AMMTIAC Quarterly, Vol. 3, No. 3 - Antimicrobial Titania … · oxide coated polymer nanofibers with a diameter on the order of 100 nm and a coating thickness ranging from 20 to 80

http://ammtiac.alionscience.com/quarterly


The AMMTIAC Quarterly is published by the Advanced Materials, Manufacturing, and Testing InformationAnalysis Center (AMMTIAC). AMMTIAC is a DoD-sponsored Information Analysis Center, administrativelymanaged by the Defense Technical Information Center (DTIC). Policy oversight is provided by the Office of theSecretary of Defense, Director of Defense Research and Engineering (DDR&E). The AMMTIAC Quarterly isdistributed to more than 18,000 materials, manufacturing, and testing professionals around the world.

Inquiries about AMMTIAC capabilities, products, and services may be addressed to:Michea l J . MorganD i rec to r, AMMTIAC

PHONE : 937.431.9322 x103EMA I L : amm t i a c@a l i o n s c i e n c e . c omU R L : h t t p : //amm t i a c . a l i o n s c i e n ce . c om

We welcome your input! To submit your related articles, photos, notices, or ideas for future issues, please contact:AMMTIACATTN: BENJAMIN D. CRAIG201 Mill StreetRome, New York 13440

PHON E : 315 .339 . 7019FA X : 315 . 339 . 7107

EMA I L : amm t i a c@a l i o n s c i e n c e . c om

Editor-in-ChiefBenjamin D. Craig

Publication DesignCynthia LongTamara R. Grossman

Copy EditorPerry Onderdonk

Information ProcessingCaron Dibert

Inquiry ServicesRichard A. Lane

Product SalesGina Nash

Recently, the Defense Science Board (DSB) released a report titledDefense Imperatives for the New Administration. The intent of thereport is to describe the critical issues that require attention from thenew Secretary of Defense to prevent military failure. While the newpresidential administration has selected the Secretary of Defense fromthe previous administration to continue to serve, the issues describedare nonetheless critical. The report is organized according to the fiveprimary missions of the Department of Defense (DoD):

1. Protect and defend the homeland

Throughout the latter half of the 20th century, the most significant threat tothe US homeland was the specter of a full arsenal exchange with the (former)Soviet Union – a threat dealt with by symmetrically assuring the destructionof their homeland. Mutually Assured Destruction, and deterrence more gener-ally, seemed sufficient to protect the homeland from attack. This complacencywas shattered along with the World Trade Center on September 11, 2001.

The DSB report suggests that one of the critical needs is to reduce ourvulnerability to Weapons of Mass Destruction (WMD). In addition toimproving foreign and domestic intelligence with regard to WMD, theDSB recommends restricting access to WMD materials, such as Cesium-137, a radioactive isotope used commonly by the medical community. Interms of technology needs, the development of advanced detection anddecontamination capabilities are required to assure our preparedness.

2. Maintain capability to project force around the world, to deter ordefeat

US conventional forces are currently second to none, but the defenseacquisition system is so slow that it continuously compromises our technologylead, and in effect extrapolates the past to the future…The Department’sexcessively slow processes limit its ability to exploit current technology…

The DSB recommends that the DoD look to the commercial sector to seeeffective and efficient business practices. In addition, the report suggests thatas technology and industry become globalized the DoD needs to developeffective strategies for leveraging this globalized industrial sector withoutcompromising its security. The Board also recommends that theDepartment embrace spiral development (i.e., continuously building, test-ing, and improving) as a conventional approach rather than an irregular one.

3. Bring stability to nations and regions

Since the end of the Cold War, 80 percent of our supplemental funds foroperations have been for stability operations. We have not yet learned to use

technology to reduce the cost of stability operations as we have for combatoperations, but technology has significantly amplified the capabilities ofinsurgents to disrupt US operations.

Part of the DSB’s focus in this area was on information sharing andcommunication technology to better achieve political objectives duringstabilization and reconstruction operations.

4. Thwart terrorism and bring terrorists to justice – anytime and anywhere

Excepting nuclear weapons, most weapons of mass destruction/disruption arelocally available or producible and need not be imported across a scrutinizednational border. Hazardous materials are located throughout the UnitedStates.

In addition to readily accessible hazardous materials, the availabilityand accessibility of defense-related information, while important and nec-essary for collaboration, is a reminder of the importance of safeguardinginformation that could be damaging if accessed by those with the will andmeans of inflicting harm on US interests worldwide.

5. Support state and local authorities in providing domestic catastropherelief

Disrupting even a single defense contractor’s operations could significantlyhinder combat operations abroad.

The example given in the report is the notion that a variety of missiles aremanufactured in Tucson, Arizona, and if this locality is disrupted througha domestic attack or other catastrophe it could threaten the supply chainand impede a military deployment elsewhere in the world. The reporturges all, including the private sector and individuals, to “nurture a cultureof preparedness to significantly reduce the consequences of attacks on thehomeland.”

These are but a few excerpts and descriptions of what is contained inthe report, and there are many more recommendations made by theDSB. While these primary mission responsibilities are succinctlydiscussed at a very high level, it is important to periodically reflect onthem to ensure that our daily efforts as scientists, engineers and pro-gram managers are best oriented to make them readily and effectivelyachievable.

Ben Craig, Editor

The entire report can be found at:http://www.acq.osd.mil/dsb/reports/2008-11-Defense_Imperatives.pdf

“It has been more than two generations since the presidency transitioned with American troopsengaged in significant combat operations…” – Defense Science Board



http://ammtiac.alionscience.com The AMMTIAC Quarterly, Volume 3, Number 3 3

ABSTRACTTitanium dioxide or titania (TiO2) has well-known photoactiveantimicrobial attributes. It also readily forms on titaniumimplants. Recently conducted in vitro studies have demonstratedincreased osteoblast functions of nanostructured TiO2 necessaryto promote the efficacy of orthopedic implants. Titania-basedceramics (bulk material, thin films, nanoscale powders, etc.) aregenerally synthesized by using either a highly corrosive andtoxic titanium tetrachloride (TiCl4) and titanium oxychloride(TiOCl2) or rather expensive and moisture-sensitive titaniumisopropoxide [Ti(C3H7O)4] as the starting chemicals. In thispaper, the technique of electrospinning has been used to fabricatenon-woven, breathable titania nanomats† employing titanylnitrate as a benign and inexpensive precursor.

INTRODUCTIONTitanium dioxide (also known as rutile) in pure or doped formhas been extensively used in a number of applications, rangingfrom food coloring, paints, cosmetics, catalysts, anti-biofouling,photovoltaic solar cells, and sunscreens to gas sensors. In addi-tion, due to its suitable energy band gap (≈ 3.2 -3.5 electron volts,eV), titania has also gained interest in photonic band gap crystalsfor the visible spectrum of light due to its high refractive index(nrutile ≈ 2.9) and low absorption properties [1]. Recently, self-cleaning wool-polyamide, polyester and cotton textiles coatedwith TiO2 have been also reported [2-7]. One of the unique phys-ical properties of titania is its photocatalysis – a photo-activated antimicrobial/disinfective activity where free radicalsgenerated from TiO2 oxidize organic matter upon activation bylight. This property makes the material a candidate for numerousmedical applications where infection control is needed. By inter-posing an effective procedure based on nanotechnology, the bonehealing can be made safer and to take place at an acceleratedpace, simultaneously eliminating or mitigating the probability ofwound infection. However, the unique photocatalytic propertyof nanostructured titania as a wound and bone fracture disinfec-tant has not been exploited hitherto. Constructing non-woven

TiO2 nanothreads and nanomats possessing a three-dimensionalscaffold structure and optimal porosity, in conjunction withphoto-activated antimicrobial activity, could provide a significantimprovement in the management of segmental bone defectsparticularly in the presence of infection. A photoactive TiO2nanomat either in pristine form or impregnated with antibacteri-al agents can be used as an effective ultralight disinfectant gauzefor wound healing upon brief activation by light.Considering that the natural scaffold (extracellular matrix or

ECM) consists of a multilayered fibrous and porous architecture,the possibility of utilizing electrospinning as a novel nanomanu-facturing technique applicable to tissue engineering has emerged.Several researchers have explored the feasibility of fabricating bio-threads containing live cells in benign polymeric matrices thatcould be used for a number of applications including woundhealing and tissue growth. Electrospun fibers are found to possessfeatures that bear morphologic similarity to the ECM of naturaltissue such as high porosity and effective mechanical properties.They therefore meet the essential design criteria of an ideallyengineered scaffold [8-9]. Recently, the authors have successful-ly carried out preliminary experiments to attach cells to theelectrospun polymeric (poly vinyl pyrrolidone or PVP) as well asceramic (alumina) nanofibers [10].With the goal of using nanomats to combat wound infection

due to its photoactive attributes, this paper describes the fabrica-tion and characterization of non-woven titania nanofibers using asimpler and more benign precursor than that which has usuallybeen used in the case of titania synthesis. In this case, an aqueoustitanyl nitrate (TiO(NO3)2) was synthesized from watersoluble titanium fluoride, as described in the ExperimentalProcedure section. First, an appropriate ceramic-polymer (ceramer)composite of titania electrospun as a continuous non-wovennanofibrillar mat was fabricated from an optimizedmixture of suitable inorganic and polymeric precursor blend.The ceramer composite was then processed carefully and the trans-formation of ceramer to high purity, crystallized and morphologi-cally optimized titania was followed by a well-conceived heat-

Abdul-Majeed Azad*Sara Lynne McKelvey

The University of ToledoToledo, OH

Zainab Al-FirdausPerrysburg High School

Perrysburg, OH



The AMMTIAC Quarterly, Volume 3, Number 34

treatment and the systematic phase evolution. The structural andmorphological features of the products, subsequent to each of suchheat-treatments, were verified by X-ray diffraction (XRD), scan-ning electron microscopy (SEM), and transmission electronmicroscopy (TEM) coupled with energy dispersive spectroscopyand selected area electron diffraction (EDS–SAED) techniques.The photoactive efficacy of these electrospun titania nanofibers iscurrently under investigation and will be reported separately.

EXPERIMENTAL PROCEDUREGranular polyvinyl pyrrolidone (PVP, average molecular weight~1.3×106) was used as the polymeric component of the inorgan-ic-organic composite. A 15 wt.% PVP solution was made by dis-solving PVP powder in reagent grade ethanol under constant andvigorous stirring. Due to the pronounced volatility of ethanolduring and after the preparation and the tendency of the solutionto dry out and leave a stiff gel in the container upon prolongedstorage, the PVP solution was prepared in small batches and onlywhen electrospinning was to be carried out. The inorganic pre-cursor used for electrospinning the ceramer composite of titaniawas made from titanium (IV) fluoride (TiF4, purity 98%). In atypical batch preparation, 1.3254 g of titanium tetrafluoride wasdissolved by adding to 50 ml of deionized (DI) water in smallincrements over a period of 90 minutes under constant stirringand gentle heating until it dissolved completely giving a cleartransparent solution of 0.214 M strength. The resulting solutionwas diluted with 230 ml of DI water, to which 20 ml of 7.4 Mammonium hydroxide (NH4OH) was added slowly under con-stant stirring. A white precipitate of titanium hydroxide(Ti(OH)4) was formed and was allowed to settle for 2 hours.The supernatant liquid was tested by adding a few drops ofammonium hydroxide. Absence of the formation of freshprecipitate indicated that the reaction was complete.The Ti(OH)4 suspension was allowed to settle overnight and

tested again for additional precipitation the next day. The super-natant liquid was decanted, and the precipitate was washed withDI water and centrifuged several times until the decanted liquidacquired a near neutral pH (~8). Fifteen milliliters of concentrat-ed nitric acid (HNO3) was added to the hydrated solidTi(OH)4[TiO2·xH2O] under constant stirring, until the precipi-tate began to dissolve. Ten milliliters of HNO3 was added againafter 30 minutes and the precipitate promptly began to dissolve.Subsequently, every 25 minutes additional HNO3 was added indecreasing volume increments (5 ml, 3 ml, and 2 ml, bringing thetotal amount of concentrated nitric acid to 40 ml) to completelydissolve the hydrated titanium hydroxide and to form titanylnitrate (TiO(NO3)2, TN), which is a clear solution with a distinc-tive luster. It is worth noting that the titanyl nitrate solution isrelatively unstable over long periods and tends to become cloudyand to re-form hydrated titania. Therefore, the precursor was syn-thesized only when needed and was used soon after preparation.In order to optimize the electrospinning conditions, the pre-

cursor solutions (TN and PVP) were mixed in different volume/volume (v/v) ratios and stirred into homogeneous viscous solu-tions. Each of these mixtures (1:1, 1:2 and 2:3 v/v) was drawninto a 10 ml capacity clinical syringe. A precision-tip 25-gaugestainless steel needle was attached to the syringe, which wasmounted on a programmable syringe pump. The preferredorientation of the syringe pump in this work was horizontal. A

custom-made direct current power supply with a high voltagesystem (30 kV maximum) using a modified version of a circuitdesign developed at NASA Glenn Research Center [11] was usedfor electrospinning (e-spinning). One terminal of the powersupply was connected to the needle, while the other was connect-ed to a grounded stainless steel collector plate.However, for the ease of sample handling and subsequent

thermal processing, ceramic plates instead of metal were used as acollector. In order to enhance the fiber collection area, a modifiedcollection set-up was devised. Two (4.5 in. × 4.5 in.) dense alumi-na plates (0.0625 in. thick) were employed. The plates were kepta half inch apart and connected together to a common junctionby attaching short lengths of electrical wires to the center of eachplate through blocks of one square inch of aluminum foil stuck tothe back of the plates with double-sided tape. This allowed thefibers to spread and collect across the plates and including theempty space between them. Other details of this set-up aredescribed elsewhere [12-13].Using the high-voltage power supply, an electrical impulse was

applied between the needle and the collectors in order to initiatethe e-spinning. After the voltage was turned on, the syringe pumpwas started. The voltage was tweaked precisely until the fibersbegan to form steadily and collect on the plate, placed threeinches away from the tip of the needle; the optimized voltagein this case was found to be 16 kV. A flow rate of 0.02 ml/h waschosen, and the ceramer fibers were spun continuously with shortintermittent interruptions of the run for periodic cleaning of theclogged needle tip.After spinning was complete, small amounts of the as-spun

composite fibers were used for characterization by scanning elec-tron microscopy. This exercise allowed the determination ofwhich mixture of the two precursors was the more optimal interms of the quality of the fibers (free from intertwining, twisting,branching, liquid globule entrapment, etc.). The remaining fiberscollected on the ceramic plates were fired at 700°C for one hourin static air as per the following heating rate-temperature-soaktime profile: 22°C (room temperature) to 500°C at a rate of½ °C/min. with a hold at 500°C for one hour; 500°C to 700°Cat a rate of ½ °C/min. with a hold at 700°C for one hour,followed by cooling from 700°C to the room temperature at arate of 1 °C/min. The rather small heating and cooling rates werechosen so as to ensure the removal of organic components with-out destroying the nanofibrillar morphological features in the endproduct and also to avoid the disintegration of the titaniananofibers into powdery grains. Subsequent to cooling, the sam-ples were collected for characterization by a host of analyticaltechniques, such as X-ray diffraction, scanning and transmissionelectron microscopy, energy dispersive spectroscopy and selectedarea electron diffraction. The results of photoactivity evaluationand biocidal efficacy of the electrospun titania nanofibers will bereported subsequently.

RESULTS AND DISCUSSIONHollow titania fibers have been prepared by soaking the electro-spun poly (lactic acid) in a 1:19 (v/v) solution of titanium (IV)isopropoxide and isopropanol, followed by hydrolysis, vacuumdrying and calcination at 450°C for ten hours at a ramp rate of15 °C/min., three hours of which were in a nitrogen atmosphereand seven hours in an oxygen atmosphere. [14] The amorphous




titania fibers were shown to be porous and500 nm across. As is evident, the techniqueinvolves several time-consuming processes:electrospinning of the polymeric skeletonfirst; preparing of inorganic sol, followed bygel formation and its hydrolysis onto theelectrospun polymeric fibers before theorganics are removed to yield the desiredceramic nanofibers. Moreover, the authorsof reference 14 claim that the surface of thefiber is not flat but contains small ovalindentations, which are due to rapid phaseseparation during the electrospinningprocess, where the solvent-rich regionsresult in pore formation. This statement,equivalent to the postulation of the exis-tence of a ‘concentration gradient’ region inthe dynamic process of fiber formation, israther speculative and unsubstantiated; thisis particularly so, in the light of the absenceof any visible ‘thinning’ along the fiberlength. If this were true, some collapsingand narrowing of the uniform tubes toform ‘sheets’ should certainly be observedin the high magnification micrographsincluded in the reference.A similar procedure has also been adopt-

ed to synthesize metal (tin and titanium)oxide coated polymer nanofibers with adiameter on the order of 100 nm and acoating thickness ranging from 20 to 80nm. [15] The preparatory technique used isalso quite elaborate and involved. It usescomplex salts, such as ammonium hexa-fluorotitanate and ammonium hexafluoro-stannate, as the precursors and requires ahalide scavenger in the form of boric acid.Furthermore, as seen from the SEMimages, the metal oxide coating is unevenand non-uniform, and the TEM imagesconfirm this. Other researchers have used asol of titanium and silicon to electrospin sil-ica-doped titania nanofibers onto a rotatingdrum. [16] The ceramic fibers wereobtained by firing them for two hours inthe temperature range of 500-1000°C.However, while the SEM images of the as-spun fibers and those dried (incorrectlyreferred to as ‘calcined’ in the reference) at100°C for two hours alone are shown, nomicrographs of the fired samples wereincluded. Hence, the morphological fea-tures of the samples calcined in the range500-1000°C is unknown.The fabrication of anatase titania porous

nanofibers of controlled diameter using anethanol solution containing both PVP andtitanium (IV) isopropoxide via electrospin-ning, followed by calcination in air at

500°C, has been reported. [17] Thisresearch shows that the average fiber diam-eter ranged between 20 and 200 nmdepending upon a number of parameters,such as the strength and ratio of PVP andtitanium (IV) isopropoxide solutions, thestrength of the applied electric field, andthe flow rate of the precursor solution.

As can clearly be seen from above, thesynthesis of pure and/or doped titaniananofibers via electrospinning: (a) involveselaborate routes, or (b) uses either a com-plex compound (ammonium fluoroti-tanate, for example) in combination with ahalide scavenger, or a relatively expensiveand moisture-sensitive titanium (IV) iso-propoxide, as a precursor. Moreover, a tech-nique of coating an electrospun polymericskeleton with titania precursor followed bycalcination does not produce the as-desireduniform and homogeneous ceramic fibers.In contrast, the present work describes theprocedure of synthesizing a simple titaniumprecursor (viz., titanyl nitrate) from a lessreactive and benign source (TiF4) andemploys it in the fabrication of high quali-ty titania nanofibers.As stated above, in order to ascertain an

optimized composition that is conducive toyield uniform ceramer nanofibers, theaqueous solution containing titanyl nitrateand the PVP solution in ethanol weremixed in three different v/v ratios: 1:1, 1:2and 2:3, keeping other experimental vari-ables (applied electric field strength, flowrate, the distance between the needle andthe collector plates, etc.) constant. TheSEM images of the as-spun nanofibers fromeach batch are shown in Figure 1.

As seen from Figure 1 (a-b), the fiberspun from a 1:1 (v/v) mixture of the inor-ganic and organic components are charac-terized by the presence of a large fraction ofnearly spherical liquid globules connectingvarious segments of the fibers. Thus, itappears that this mixture is subject to thecombined phenomena of electrospraying(spherilization of the charged droplet upondischarging) and electrospinning. A largepopulation of globules, rather than linearfibers, suggests that the mixture might nothave attained the optimal viscosity in orderto satisfy the conditions of forming perfectnon-woven fibers. For this purpose, thepolymeric content of the solution wasincreased in the ratio TN:PVP = 1:2. TheSEM images displayed in Figure 1 (c-d)indicate that this strategy helped, as thedensity of liquid blobs greatly diminished,

Figure 1. SEM images of the ceramernanofibers spun from a solutioncontaining TN and PVP in volumetricratio of 1:1 (a-b), 1:2 (c-d) and 2:3 (e-f).

(a)

(b)

(c)

(d)

(e)

(f)




though was not eliminated totally. Some evidence of fiber bend-ing can also be seen, which indicates that the ratio of the twocomponents in the spinning mixture still needs to be optimized.The 2:3 (v/v) mixture of TN:PVP appeared to form the mostdesired microstructure when electrospun, as could be seen fromthe nonwoven fibers of uniform thickness in Figure 1 (e-f ). Thesubsequent discussion pertains to the fibers which were electro-spun from a homogeneous solution containing the inorganic andorganic precursors in the volumetric ratio of 2:3.

The morphological features of the fired nanofibers of electro-spun titania are shown in Figure 2a. The intact nature of thefibers in the layered mats of titania that were present in the as-spun material can be discerned in the calcined sample as well.This is by virtue of the judicious firing scheme adopted in thiswork; even a slightly higher ramp rate has been found to causesevere fiber rupturing, rendering them into a powdery mass, dueto faster combustion of the polymer with a concomitant andsudden release of a copious amount of gaseous products. Theenergy dispersive spectrum (EDS) of the same is shown in Figure2b, where the signals due to oxygen and titanium alone are seen;no peak belonging to carbon is present, meaning that the heatingprofile selected in this work was able to eliminate polymericcomponents quantitatively.The TEM images of the nanofibers fired at 700°C as per the

schedule described in the previous section are shown in Figure 3.It is evident that the heat treatment used in the present work

has preserved the fibrous artifact in the processed material.Moreover, the titania fibers are porous and less than 100 nmacross; they are comprised of interconnected monosized grains,

making the structure quite breathable and therefore amenable forthe intended medical application. Using the wavelength of theelectron beam (0.0335Å) and the length of the SAED pattern onthe film, the interplanar distances (d-spacings) for successivediffractions were calculated. They match the d-spacings reportedin literature for the anatase phase of titania. This is corroboratedby the X-ray diffraction pattern of the powdered nanofibers, asshown in Figure 4; the selected area electron diffraction signatureof the calcined fibers is also shown as an inset.

CONCLUSIONTitanium dioxide nanofibers were successfully electrospun as apolymeric composite from a benign and inexpensive titaniumprecursor, viz., titanyl nitrate and polyvinyl pyrrolidone. The as-spun ceramer fibers possessing uniform thickness upon firingwere formed into breathable titanium dioxide nanomats ofanatase modification upon a single-stage firing in air at 700°C forone hour.

ACKNOWLEDGMENTZainab Al-Firdaus was part of this research during summer 2007,when she was an 8th grade student at Perrysburg Junior HighSchool. She is currently a sophomore at Perrysburg High School.

NOTES & REFERENCES* Corresponding author; e-mail address: [email protected]† Nanomats are 3-dimensional carpet-like, supportless, independent,modular structures with nearly identical porosity in their bulk. Thesespecialized nanostructured materials can be used either as such or incombination with other components, such as dyes or drugs or both, toenhance their anticipated functional attributes.[1] Kingrey, W.D., H.K. Bowen, and D.R. Uhlmann, Introduction toCeramics, 2nd ed., John Wiley, 1990.[2] Peblow, M., Nature, Vol. 429, 2004, p. 620.[3] Bozzi, A., T. Yuranova, and J. Kiwi, J. Photochem. Photobiol. A:Chem., Vol. 172, 2005, p. 27.[4] Bozzi, A., T. Yuranova, I. Guasaquillo, D. Laub, and J. Kiwi, J.Photochem. Photobio. A: Chem., Vol. 174, 2005, p. 156.[5] Meilert, K.T., D. Laub, and J. Kiwi, J. Molec. Catal. A, Vol. 237,2005, p. 101.[6] Yuranova, T., R. Mosteo, J. Bandata, D. Laub, and J. Kiwi, J. Molec.Catal. A, Vol. 244, 2006, p. 160.[7] Daoud, W.A., J.H. Xin, and Y. H. Zhang, Surf. Sci., Vol. 599, 2005,p. 69.[8] Li, W.J., C.T. Laurencin, E.J. Caterson, R.S. Tuan, and F.K. Ko, J.Biomed. Mater. Res. Vol. 60, 2002, p. 613.[9] Kenawy, E., J.M. Layman, J.R. Watkins, G.L. Bowlin, J.A.Matthews, D.G. Simpson and G.E. Wnek, Biomaterials, Vol. 24, 2003,p. 907.

Figure 2. (a) SEM showing the intact nature of the mat structure ofthe fired fibers and (b) EDS signature in the ceramer compositefired at 700°C/1h. Figure 3. TEM images of the ceramer nanofibers fired at 700°C/1h.

Figure 4. XRD signature of the nanofibers calcined at 700°C/1h(inset: SAED pattern).

(a) (b)

200 nm 100 nm




[10] Azad, A.-M., unpublished research, 2007.[11] Eichenberg, D.J., “High-Voltage Droplet Dispenser,” NASATechBriefs, 2003, http://www.nasatech.com/Briefs/Nov03/LEW17190.html.[12] Azad, A.-M., Mater. Sci. Eng. A, Vol. 435–436, 2006, p. 468.[13] Azad, A.-M., M. Noibi, and M. Ramachandran, Bull. Polish Acad.Sci., Vol. 55, 2007, p. 195.

[14] Caruso, R.A., J.H. Schattka, and A. Greiner, Adv. Mater., Vol. 13,2001, p. 1577.[15] Drew, C., X. Liu, D. Ziegler, X. Wang, F.F. Bruno, J. Whitten,L.A. Samuelson, and J. Kumar, Nano Lett., Vol. 3, 2003, p. 143.[16] Choi, S., B.C. Chu, S.G. Lee, S.W. Lee, S.S. Im, S.H. Kim, andJ.Y. Park, J. Sol-Gel Sci. Tech., Vol. 30, 2004, p. 215.[17] Li, D. and Y. Xia, Nano Lett., Vol. 3, 2003, p. 555.

Dr. Abdul-Majeed Azad is an Associate Professor in the Department of Chemical Engineering at the University ofToledo; he has been serving the university in this capacity since August ’03. Dr. Azad began his career as a ResearchScientist studying fast breeder nuclear reactor materials with a special focus on their processing and characterizationaspects. His current interests are in the area of nanomaterials, including metals, functional ceramics and composites.Dr. Azad is particularly interested in the relevance of nanomaterials to clean energy, catalysis, sensors, biomedicalapplications and other nanotechnologies.

Ms. Sara Lynn McKelvey was born and raised in Toledo, Ohio. Ms. McKelvey received undergraduate degrees inchemical and bio-engineering from the University of Toledo in December 2008.

Ms. Zainab Al-Firdaus was born in Columbus, Ohio, and currently attends Perrysburg High School. Ms. Al-Firdausplans to attend The Ohio State University upon completion of high school. She is an ardent Jeopardu fan and plays thepiano.

AMMTIAC Success Story:Commercial Manufacturer Benefits from DoD Technology Transfer

Beyond the primary charge of providing technical solutions to thewarfighter, it is also a mission of the Information Analysis Centers(IACs) to transfer, or “spin-off,” innovative technologies to theUS industrial base, as AMMTIAC has recent-ly done. Through a commercial inquiry,AMMTIAC provided a manufacturer of wireand cable machinery with a machining solu-tion that employed technology originallydeveloped for the US Army to solve a produc-tion issue and improve product quality.The manufacturer identified the root cause of

the production issue as a poor surface finish onmachine components called forming rolls. Theserolls are grooved pieces of high strength steel used to shape individ-ual strands of wire so that they can be wrapped together to form alarger cable. Due to the weight of the components (60 lbs each) andthe complexity associated with machining the wire grooves, theproper surface finish needed to shape the wire strands is not readilyachieved by traditional machining methods (e.g., turning, grinding,etc). Engineers from AMMTIAC collaborated with the componentmanufacturer to evaluate possible solutions and decided the bestapproach is to apply a superfinish to the complex surface geometryof the forming rolls to achieve the desired surface finish.Chemically Accelerated Vibratory Surface Finishing (CAVSF),

more frequently referred to as Superfinishing, is a process that wasoriginally developed by the US Army to improve the surface

finish and fatigue life of compo-nents in helicopter transmissions.Superfinishing uses a chemically-

formulated conversion coating to oxidize thepeaks on a surface after which they are placed ina vibratory media container, where the oxidizedpeaks are removed, leaving a microscopically-smooth surface finish. Metallic componentsthat have undergone a superfinishing operationhave demonstrated a 300% improvement in thefatigue life of the surface. Transition of super-finishing technologies has netted significantresults in the automobile racing community, as

it has significantly improved the overall performance and servicelife of car transmissions and ring and pinion gears.Application of superfinishing technology to the forming rolls

produced a drastic improvement in the quality of the wire beingproduced. The improved surface finish (less than four micro-inches)has allowed the machinery manufacturer to produce individualstrands of wire that are free of defects, eliminating a long-standingproduction issue. The success achieved by superfinishing theforming rolls has lead the machinery manufacturer to considerpermanently using the superfinishing process in the productionof forming rolls. In addition, AMMTIAC is working with themachinery manufacturer to identify other machine componentsthat would benefit from the use of superfinishing technology.



We provide answers to customers looking for copies ofreports, legacy data and information, or engineeringconsulting services.

Here are just a few of the numerous inquiriessubmitted to us each month:

Given the fact that current steel making practicesproduce little in the way of inclusions that arestrung out by hot and/or cold working, what, ifany, benefit does a grain direction provide in theway of strength, toughness or fatigue resistance?

I need some more information about BlastMitigation (and a demonstration film clip, ifpossible) and the polymer coatings whichincrease blast resistance of existing andtemporary structures.

I am looking for an accelerated environmentaltest protocol that can be run for corrosion testingof zinc plated mild steel samples and a method tocorrelate these results to actual life.

Please be kind enough to supply me withinformation on the latest technologies to do NDTof pre-stressed concrete pipelines of diametersranging from 1m to 3.5m.

I need the following information about digitalradiography:1) its feasibility during maintenance/overhaul of steam generators of thermal powerplants, and 2) data of thermal power plants whichare using this technology.

Do you have information on hydrogenembrittlement data on 4340 and 300M steels?Stress versus embrittlement, baking time versushydrogen content, empirical formulas?

WHAT’S YOUR QUESTION?AMMTIAC provides a government-subsidized, free technical inquiry service. We have the expertiseto jump-start or support your project — the first four hours of every question are free.

What is the AMMTIAC Inquiry Service?As one of the Department of Defense InformationAnalysis Centers (IACs), we provide up tofour free hours to answer technical andbibliographic inquiries related to our scope –materials, manufacturing and testing.

Who is Eligible to Use the Service?We have answered inquiries for individualsfrom virtually all sectors, including the Departmentof Defense and other government agencies,government contractors, industry, academia, andforeign allies of the U.S.

How Does AMMTIAC Obtain Answersto Technical Inquiries?We manage an extensive library of approximately300,000 government technical reports, conferencepapers, presentations, and journal articles related tomaterials, manufacturing, and testing.

With an experienced technical staff on hand,answers are obtained quickly through our library orother private research systems, including DTIC’sScientific and Technical Information Network(STINET) and Total Electronic Migration System(TEMS), and NASA’s Technical Reports Server(NTRS).

What If My Inquiry Takes More Than 4 Hours?Sometimes an inquiry will require extended services.These services include comprehensive literaturesearches, summarizations of literature results,material property compilations, failure analysis,selection of materials, manufacturing and testingtechnologies, test planning and engineering design.

If your inquiry requires more than four hours ofsupport, we will discuss our extended research andengineering options and provide a tailored costestimate that best suits your needs. Ultimately allparties must agree to a work contract prior to anywork beyond the four free hours of support.

How Do I Submit an Inquiry?You can submit an inquiry on our website at http://ammtiac.alionscience.com/experts, by sending an email [email protected] or by calling 315.339.7090.



INTRODUCTIONThe natural environment produces most everything humans needto survive. However, to attain knowledge, security, convenience,creature comforts and longevity, society relies on manufacturedproducts and services. Derived from the Latin phrase manu factus,meaning to make by hand[1], manufacturing affects almost everyaspect of our lives, from the cars we drive to the water we drink. Theability of a nation to meet the need of its inhabitants through theproduction of goods and services is a major determining factor inthe prosperity and longevity of that nation. The ancient Romanswere able to sustain a flourishing empire for several centuriesthrough the development of freshwater transportation technology(aqueducts) and a well-maintained system of roads. These wereachievable because Roman engineers were able to identify criticalneeds of the empire and developed products and methods to meetthose needs. This article presents an introduction to manufacturing,production processes, and the concepts, technologies, and strategiesemployed to provide the high-quality products and services thatmake modern society possible.

From Concept to Finished ProductManufacturing is the process of taking raw materials or componentsand making them into a finished product. Figure 1 illustrates thegeneral manufacturing process from initial concept to a distrib-utable product. The purpose of manufacturing a product is typical-ly to meet an identified need or to fulfill a void (i.e., the shortage orabsence of a product). Once a need or void is identified and the fea-sibility of developing and manufacturing the desired product is

assessed, it is necessary to formulate a plan to fulfill the require-ments. This is accomplished by establishing design parameters. Thematerials are then selected and a prototype is developed.If the prototype meets design and performance requirements, the

concept is then moved into the production stage. In this stage, amanufacturing process is selected and the production system is cho-sen. Quality assurance and control ensure the product meets designrequirements and performance specifications and is sufficiently freeof defects. The finished product can then be packaged and distrib-uted. The following sections present additional detail of the productdesign, development, and production processes.

PRODUCT DESIGN & DEVELOPMENTThe first step in designing a product is to properly define the need.Clearly defining a need, and with it the required performance speci-fications and operational parameters, will result in a more focused andefficient product development process. Feasibility analyses for sys-tems, assemblies, and subsystems can be conducted once the relevantparameters are set. Material choices can also be made at this point.Once the design is sufficiently mature, a prototype can be built.Through the use of metrics, design parameters, such as design

function, end user, design fit, operating environment, desired lifecycle, and desired quantity, are defined to ensure high product qual-ity. From these parameters, the range of potential materials andprocesses that may be considered for production can be more read-ily identified by the design team.

Design ParametersIdentification and definition of design specifications and perform-ance requirements is critical to the successful development of aproduct. Some considerations include design function, the end user,design fit, operating environment, desired life cycle, and desiredquantity. If these specifications and parameters are not definedupfront, the cost and time required to develop a product couldincrease unchecked, possibly at an exponential rate. It is more diffi-cult to remedy design oversights later in the development process,and the cost of correction can increase by an order of magnitude ateach successive step in the product development cycle.Design parameters also significantly influence material selection

for a product. Choosing the proper material, or combination ofmaterials, is dependent on the operating conditions, environment,and desired life span of the product. Material selection is also depend-ent on environmental restrictions, and the chosen material and/orprocessing method must comply with applicable regulations.

Product Design ToolsThere are several tools that can be used to develop performancerequirements. One of the more prevalent techniques for transforminguser needs into quantifiable design, quality, and performance criteria,


Christopher W. FinkAMMTIACRome, NYtechsolutions 9

An Introduction to Manufacturing

Figure 1. Manufacturing Process from Initial Concept to FinishedProduct.

ConceptDevelopment

Product Design&Development

Identify – needs and requirementsResearch – feasibility

Establish Metrics – Used to convert needs & requirements to design parametersSet Design Parameters

– Design requirements– Performance specifications

Concept DesignSelect MaterialsMaterial Properties– Environmental regulations

Develop Protype

Production

FinishedProduct

Select Manufacturing Process & Equipment – How to fabricate a productgiven design & materials

– Machinery– Tools

Choose Production Type – Maximize output & quality, while minimizing unit cost– Mass production– Job shop– Agile manufacturing

Maintain Quality – Meet design requirements & performance specifications– Quality assurance– Quality control– Statistical quality control

Package and distribute – finished product




at both the system and subsystem level, is Quality FunctionDeployment (QFD)[2]. QFD is a methodology for transformingthe needs that are provided by the customer into design specifica-tions and performance requirements and then quantifying how wellthe customer’s needs are met. Beyond the mere synthesis of perform-ance specifications, a QFD can be used to prioritize customer needsand evaluate subsequent engineering solutions to ensure that designand development efforts are focused appropriately.In the past, the relationship between design engineers and man-

ufacturing engineers has often been represented by the sentiment of“we design it, you build it”[3]. As a result, manufacturing staff haveoften been left to solve unanticipated production problems becausethey were not involved in the design process. A different approach,which can eliminate this mentality and potentially reduce unex-pected problems, is to employ multidisciplinary design teams.Comprised of representatives from all stages of the product devel-opment cycle, multidisciplinary design teams ensure that the prod-uct can be made from existing materials and processes, will meetdesign specifications, and will perform as required while meetingbudgetary constraints. In addition to ensuring that the proper met-rics are established, these teams ensure that the selected designoption is the best choice for all stages of production and develop-ment rather than the one that is most familiar to the design team.

Material SelectionOne of the most daunting tasks of any design activity is choosingthe materials for production. Material selection for all compo-nents is influenced by design specifications, performance require-ments, process limitations, and environmental factors. Choosinga material without first taking into account all requirements andspecifications can result in poor quality or defective productsand abnormally high maintenance and replacement costs. Inaddition, material selection can be limited by the process neededto produce a material. For example, some materials that can befabricated in a laboratory setting have difficulty being scaled upto a satisfactory production rate because the fabrication processisn’t fully developed.Designers have a tendency to develop design concepts based on

familiarity with materials and processes. While being familiar withthe materials and processes in use can be valuable, a narrow view mayexclude combinations of materials and processes that could prove tobe a more efficient and produce higher quality components[4].

Environmental Factors in Material SelectionIn addition to design specifications, performance parameters, andprocess limitations, environmental factors can have a significantimpact on the selection of materials for a product. For example, theRemoval of Hazardous Substances (RoHS) Directive was enactedby the European Union (EU) in July 2006, with the goal ofrestricting “the use of certain hazardous substances in electrical andelectronic equipment”[4]. The hazardous substances outlined forrestriction in the 2006 RoHS Directive are lead, cadmium, mercu-ry, hexavalent chromium, polybrominated biphenyl (PBB), andpolybrominated diphenyl ether (PBDE). Restriction on the use of

lead has had a significant impact on the international electronicsindustry, as manufacturers have had to switch to lead-free soldersfor new electronic components in order to meet EU regulations.While there is no US equivalent to RoHS, the directive has hada significant impact on US commercial manufacturing sinceUS-based manufacturers must adhere to these regulations tomaintain a global market share.

PrototypingTypically, the last step before scaling up production is building aprototype of the product. Physical prototypes are built to validatethe product’s design and material choices, and to ensure that theproduct meets performance specifications and design require-ments. In some cases, prototypes may also be employed to validateone or more production processes.The process of prototyping can be very expensive, since produc-

tion machinery and materials may have to be obtained to build aprototype, which may or may not meet requirements. However,these costs are necessary since the design must be validated beforeit can enter into full production. Toward the end of 20th century,the growing need for an easier method of creating models and pro-totype parts led to the invention of rapid prototyping (RP) systems.

Rapid PrototypingRapid prototyping systems, such as 3-D printing, additive fabrica-tion, and solid free-form fabrication, transform computer-aideddesign (CAD) drawings into layers (thin cross-sections that collec-tively make up a component). These layers are then manufacturedone on top of another until the model is complete.[5]Stereolithography, which was the first type of RP system created,was invented in 1986.[5] Through the use of processes like fusedeposition modeling, selective laser sintering (SLS), and stereolith-ography, the RP industry has revolutionized the way new productsare designed and manufactured. It no longer takes hours to set upthe tooling and computer numerical control (CNC) systems tomake prototypes and short-run parts. Rapid prototyping enablesdesign teams to quickly fabricate functional models and identifycandidate production processes.

THE PRODUCTION PROCESSDetermining how to make a product in many cases is just as diffi-cult as deciding what product to make to fulfill a need. The selec-tion of the manufacturing process that will be used to fabricate aproduct is often dictated by the design of the product; however,process limitations can alter the final design of the product whenthe processes available lack the ability to produce the desired mate-rial with properties that meet performance requirements. Forinstance, the process for manufacturing a certain product may notbe sustainable outside of a prototype setting, resulting in the needfor a materials substitution or even a complete component redesign.In addition to material limitations, tool selection can affect manu-facturing processes. The term “tool” represents more than simplehand tools; it represents any and all equipment (e.g., CNC machin-ery, automated systems, etc.) needed to produce a component.

techsolutions 9http://ammtiac.alionscience.com/quarterly



Manufacturing Process and Equipment SelectionOnce the basic product has been developed, the manufacturingprocesses are selected. For example, to fabricate a plastic componentthe proper molding process (e.g., traditional injection molding, resintransfer molding, or vacuum assisted resin transfer molding) must beselected to ensure product quality and meet customer demand.Maintaining product quality while meeting production demand aretypically the primary considerations when selecting a manufacturingprocess. In addition, the manufacturing process is often selectedbased on the design of the product. In some cases, after the processis selected the design is altered to accommodate the limitations of thefabrication process (e.g., machine production capacity).Machinery and tools needed to fabricate the product are selected as

part of the manufacturing process. Similar to the selection of themanufacturing process, there are many factors (too many to discuss inthis article) that are considered when selecting machinery and tools.For instance, the machinery must be able to handle the productionrate, and it is often selected based on the ability to hold a dimension-al tolerance, durability, and ease of maintenance. The manufacturingprocesses and machinery must also adhere to the production method-ology that best meets these production requirements.The production rate requirements for a manufacturing line are

largely determined based on product demand. The production raterequirements influence the amount of flexibility in a line.Production lines with minimal product variety but large productionquantities traditionally yield a lower unit cost (cost per product).The lower unit cost is partially attributed to the simplicity ofthe manufacturing line, but it is primarily less because the initialstartup costs are distributed over a larger number of units produced.However, production lines that have limited flexibility have difficul-ty adapting to changing customer needs.

CNC MachiningInvented in 1947 by John Parsons[6], a CNC machine is anymachine that uses computer logic code to control movements andperform material shaping operations[7]. The logic code used to con-trol a CNC machine is generated from an electronic version of anengineering drawing. The drawing is entered into a computer-aidedmachining (CAM) program, which subsequently assigns tool pathsand writes the logic code required to perform the operation. CNCis used for several types of machining equipment, including lathes,milling machines, laser cutters, abrasive waterjet cutters, and stamp-ing machines.CNC machines produce higher quality components and have

lower reject rates than conventional machines because of their abil-ity to maintain precise coordinates on all work axes. CNC machinesalso produce components at a faster rate because they have shortersetup and cycle times. In addition to producing higher quality com-ponents at a faster rate, CNC machinery can be easily adapted forboth low volume and mass production, thereby eliminating theneed for expensive specialty production machinery. As the technol-ogy behind CNC systems has evolved, smaller manufacturing cellswith the ability to produce several different components with evenhigher accuracies have been developed.

Rapid MachiningRapid machining is considered in some manufacturing circles to bethe next evolution of CNC machining. Both additive (i.e., building

one layer at a time) and subtractive (i.e., machining from a solidblock) prototyping systems have become conventional design toolsbecause they offer product designers a greater selection of produc-tion materials and can make parts with greater accuracy, produce abetter surface finish, and can be produced much faster than previ-ous prototyping processes. 3D printing and other RP systems haveestablished themselves solidly as viable agile, rapid manufacturingsolutions that will continue to foster change in the 21st centurymanufacturing industry.

Robotics and AutomationAlong with CNC machining and rapid prototyping, the use ofautomated processes and robotics has revolutionized the manufac-turing industry (see Figure 2). The earliest use of industrial robotsin a manufacturing environment was during the 1960’s, when thefirst programmable transfer machine (i.e., robot) was introduced.This machine, nicknamed Unimate after the parent company, wasused by General Motors to weld cast auto body parts[8].The term automation quickly gained broad usage as processes

became less dependent on human intervention. Originally devel-oped to reduce direct labor costs[9], automation has improvedprocess efficiency, safety, and overall quality. Automation and robot-ics have transformed the manufacturing industry by shorteningprocess cycle times and eliminating the need for workers in someprocesses. For example, in the automotive industry all welding ofautomobile chassis is performed by robots. Not only is robotic weld-ing completed faster than welding performed by humans, but thewelds are consistently more accurate. This automated processenables manufacturers to produce cars faster and reduce the overallcost of building a car.Robots are used in almost all facets of manufacturing processes.

In many factories, robots and automated processes are used for eachstep of product assembly, including inspection, packaging, and stor-ing for shipment. Automated systems have eliminated human errorin most processes; they have also eliminated human involvement inmany hazardous procedures. For instance, robots now handle andstore hazardous materials and perform other dangerous tasks thatwere previously carried out by humans.Robotics and automation have made manufacturing processes safer,

AMMTIACA D VA N C E D M AT E R I A L S , M A N U FA C T U R I N G A N D T E S T I N G

Figure 2. CNC milling of components for the Joint Strike Fighter[10].




more accurate, and faster, while simultaneously eliminating the needfor many assembly workers. These advances have reduced the numberof lower skill jobs but have also created a demand for a new level ofskilled workers to supervise the automated processes. These new jobsare needed to prevent errors from occurring during the manufacturingprocess and to minimize the impact of errors when they do occur.

Selecting a Production SystemA production system is an operational method that is established tomeet all facets of a customer’s production requirements. The threemost common production system types are mass production, jobshop production, and agile production. Setting up a successfulproduction system is a delicate balancing act between achieving pro-ductivity requirements (i.e., rate and variety) and managing costs.Therefore, the optimummanufacturing lines (e.g., processes, machin-ery, and tools) are set up using the production system that will producethe highest quality goods at the lowest cost, while possessing theflexibility in machinery to adjust to meet changing customer needs.The type of production system that is selected depends mostly on

the number of parts needed in a production run and the variety ofparts desired. The quantity of parts to be produced is typically setin a production forecast. This forecast also helps production man-agers order the proper types and quantities of raw materials to beginproduction, regardless of the type of production system.

Mass Production (High Volume, Low Variety)The concepts of mass production and the assembly line originatedin Henry Ford’s Highland Park production facility in the early 20thcentury[11]. Mass production is most commonly used to manufac-ture a large quantity of product. Facilities that perform traditionalmass production are typically capable of producing large quantitiesof a limited variety of products. The production of goods in largequantities is traditionally the least expensive method per unit ofproduct because the production costs are distributed over thousands,sometimes millions, of products. However, the lack of process agili-ty can hinder mass production facilities because transitioningprocesses and machinery to make new products can be expensive.

Job Shop (Low Volume, High Variety)A job shop production facility traditionally adapts to accommodatethe job at hand and typically produces several types of componentsin smaller quantities. These facilities often modify the productionline after completion of each run in order to accommodate the nextproduct. Job shops are especially useful for fabricating spare parts orcritical out-of-date parts because the part can be produced quickly.Moreover, the machinery in job shops is versatile and can be set upto fabricate a variety of products. Several large production facilitieswill have an internal job shop to handle refurbishing or orders forindividual parts (usually warranty-related). However, most inde-pendent job shops are small facilities that have five to ten machinesand between ten and 40 employees. Figure 3 shows an example ofthe layout for a low volume, high variety assembly line.

Agile Manufacturing (High Volume, High Variety)An agile manufacturing facility combines the production ratecapabilities of a mass production facility with the versatility tomanufacture a variety of products. Establishing a production facil-ity to manufacture products at a high rate while possessing theability to adapt to meet customer demand can be challenging andrequires extensive personnel support. Production lines must be setup to enable a rapid reconfiguration of the process without sacri-ficing quality or producing an unacceptable amount of waste. Toestablish an agile production facility, production teams create toolkits for each product. These kits consist of any and all tooling (e.g.,drill bits) and accessories (e.g., brackets that secure material formachining) that are used to fabricate a given product.To optimize space in a fast-paced manufacturing facility, pro-

duction lines are operated as lean as possible. This allows thevacant space to be used to store excess inventory. Running a leanproduct line means that the throughput (i.e., the amount of workthat can be done in a period of time) is maximized while the work-in-progress (i.e., unfinished products) is minimized. A product“pull” methodology is employed rather than a “push” to ensurethat parts are produced only as they are needed. In a pull system,when a production station reaches a certain inventory level, the

techsolutions 9

BR

ENG PARK

ASB 820 ASB 230OFFICES

226

223

224

210 210 210P/U P/U

TOOL PARKFUNCTIONAL TEST EQUIPMENT TOOL PARK

ASB280

STD TOOL&

TOOL INSPV. STAB.

L.E. INSTL.529

M.C.S.C.

BR

STAGING& STORAGE

S.C. CLASS.PARTS

FUNCT.TEST

S.C.

225 225

FAJ FAJ

220 220

FAJ FAJ

220 220

HARNESS & CONSOLE ASSEMBLYS.C.S.C. BR

BR

F.F.

200FAJ

4123 4125

4126

412241214120411941184117

4124

RTP / 200 P/U

200 P/U / RTP

4116

Figure 3. Example of a Job-Shop (Low Volume, High Variety) Assembly Line: F-22 Final Assembly.




operators signal to processes upstream (i.e., closer to the beginningof the production line) that a certain amount of a component (e.g.raw material or semi-finished product) is needed to ensure that theflow of products is continuous. As a result of following this method-ology, products are manufactured as needed, and no unnecessaryinventory is retained.When running a high production-rate, agile manufacturing facil-

ity, a concerted effort must be undertaken to ensure that the prod-ucts meet quality standards. Since there are a variety of productsbeing fabricated, the potential for defects and parts that need to bereworked increases. Quality control measures and processes areestablished to ensure that a high level of quality is maintained acrossall production lines.Agile manufacturing facilities need to be operated with a spirit of

innovation and a focus on continuous improvement. An openforum for improving the processes used to manufacture a product isvital, as workers from all levels of production will be able to giveinput that leads to improved production efficiency and quality.

QualityThe ability to manufacture high quality products is paramountand often supersedes production rate and cost. A product is deter-mined to be of sufficient quality when customer expectations andrequirements are met or exceeded in all areas. Fabricating qualityproducts requires a fluid relationship between management, whoset the quality standards, processes, and methodologies, and theproduction operators.Quality Assurance (QA) and Quality Control (QC) measures are

implemented to ensure that the customer expectations are met. Thedefinitions of QA and QC are commonly mistaken for one anoth-er. According to the American Society of Quality (ASQ), QA isdefined as “the planned and systematic activities implemented in aquality system so that quality requirements for a product or servicewill be fulfilled,” whereas QC is defined as “The observation tech-niques and activities used to fulfill requirements for quality”.[12]The essential difference between the two is that QA is performedbefore manufacturing takes place, while QC takes place during andafter the manufacturing process.

Statistical Quality ControlStatistical quality control (SQC) is an example of a QC methodol-ogy that is used to ensure that products of the highest quality can bemade efficiently. Process controls, like SQC, place an emphasis onmaintaining control of the process to ensure quality. Typically, prod-ucts have a critical dimension that must be precisely controlled. Ifthese dimensions fall within a standard deviation range from themean (average) dimension (see Figure 2), the process is said to becontrolled. The concept of statistical process control was originatedby Walter Shewart, an engineer at Bell Labs in the 1920’s[13]. Theevolution of quality control methodologies has led to the use ofstatistical methods to help identify the root cause of defects. Inmany cases, employing quality control methods to identify rootcauses of defects is built into a business management theory.

Measurement ToolsThe ability to measure and ensure a certain level of quality is only asgood as the tools used to assess the quality of a product. There is awide range of tools available to assess the physical attributes of acomponent, regardless of its size or shape. For example, measure-ment of the inner diameter of a hole can be performed using anadjustable measuring device, such as a caliper or micrometer, or apre-measured validation device (commonly referred to as a go/no-gogage). When measuring dimensions on a smaller scale, a device calledan optical comparator will magnify a given area of the component,which is then compared to a scaled drawing of the part. When adimension needs to be measured to the hundred-thousandth or mil-lionth of an inch, a computer-operated device called a coordinatemeasurement machine (CMM) is used to take measurements andcompare them to an electronic version of the component drawing.

COMMERCIAL MANUFACTURING VS. DEFENSEMANUFACTURINGWhile manufacturing for the commercial and defense sectors havesome similarities, they are easily distinguished by their differences.Commercial manufacturing is driven by profit and maintaining orincreasing their market share among the consumer base. In thedefense sector, national defense and system readiness are paramountissues, as they are the expressed missions of the DoD. It is true that

AMMTIACA D VA N C E D M AT E R I A L S , M A N U FA C T U R I N G A N D T E S T I N G

Figure 4. Sample Control Chart.

1/1/05

1/2/05

1/3/05

1/4/05

1/5/05

1/6/05

1/7/05

1/8/05

1/9/05

1/10/05

1/11/05

1/12/05

1/13/05

1/14/05

1/15/05

1/16/05

1/17/05

1/18/05

1/19/05

1/20/05

1/21/05

1/22/05

1/23/05

1/24/05

1/25/05

1/26/05

1/27/05

1/28/05

1/29/05

1/30/05

1/31/05

NumberofImperfections

Number of Imperfections per Production Run

� Upper Control Limit� Lower Control Limit� Sample Mean� Average Daily Imperfections

�

�

�

�

6.0

5.0

4.0

3.0

2.0

1.0

0.0

�

�

�

�

�

� �

�

�

�

�

��

��

�

��

��

��




most defense manufacturing is performed by private contractors andturning a profit is a goal but, unlike the commercial market, thedefense market is relatively fixed, thus limiting market growth. Also,all defense products are subject to stringent acquisition rules for con-tracting, known as the Defense Federal Acquisition RegulationSupplement (DFARS). Beyond purchasing and contracts, DFARSregulates many aspects of how defense contractors conduct business,such as engineering and design, supplier selection and subcontract-ing, quality metrics, and, depending on the type of contract, theamount of profit the company may take is also predetermined.However, regulatory and contractual matters are not the only dif-

ference; defense systems are traditionally produced in smaller quan-tities than commercial products. For example, Boeing has producedmore than 1,400 commercial 747 jumbo jets since their inceptionin 1969,[14] whereas they have only produced 744 B-52’s for theUS Air Force[15]. Coupled with high development costs and finiteproduction runs (the last B-52 was delivered in 1962), theDepartment of Defense has opted to use prime contractors (e.g.,Boeing, Lockheed Martin, and Northrop Grumman) to produceaircraft at their own facilities. However, commercial productionfacilities strive to run at maximum capacity with little room forsurge. Conversely, military production requires facilities to possessthe capacity to meet any surge caused by the onset of conflict,retirement of a previous system, or other eventualities. This funda-mental difference in production methodology has prompted sever-al commercial manufacturers to cease military production work.

SUMMARYEach production situation is unique and has its own challenges.However via thorough planning, careful product design, and due

diligence in production and quality management, any product canbe made to meet and possibly exceed customer requirements.Designing a product to meet a need starts with identifying theform, fit, and function of that product. Metrics like the QFDare instrumental in transforming customer needs into designrequirement and performance specifications. After developmentof requirements and specifications, materials and processes areselected that will meet those requirements. A plan for productionthat takes into account the materials, tools, and labor requiredfor production is imperative to ensure the product meets the cus-tomer’s needs. This production plan has a significant influence onthe type of production methodology (high volume/low variety, lowvolume/high variety, high volume/high variety) in the productionfacility. Selecting appropriate quality assurance measures (qualitycontrol programs, methodologies, and inspection tooling) willensure that goods made in the production facility will meet boththe design specifications and performance requirements as set forthby the design team.

REFERENCES[1] “Manufacture,” Merriam-Webster Online Dictionary, Merriam-Webster Online, November 2008.[2] Akao, Y., “Development History of Quality Function Deployment,”The Customer Driven Approach to Quality Planning and Deployment,Minato, Tokyo 107 Japan: Asian Productivity Organization, p. 339, 1994.[3] Boothroyd, G., P. Dewhurst, and W. Knight, Product Design forManufacture and Assembly, Second Edition Revised and Expanded, MarcelDekker, 2001.[4] “RoHS,” National Weights and Measures Laboratory, http://www.rohs.gov.uk/[5] “30 Years of Manufacturing Technology”, NASA Tech Briefs, Vol. 30,No. 6, June 2006.[6] “John T. Parsons,” National Inventors Hall of Fame, http://www.invent.org/Hall_Of_Fame/118.html[7] “CNC Machine Tool,” How Products are Made, http://www.madehow.com/Volume-2/CNC-Machine-Tool.html[8] “The 2003 Inductees: Unimate,” Robot Hall of Fame, http://www.robothalloffame.org/unimate.html[9] Ostwald, P.F. and J. Munoz, Manufacturing Processes and Systems,9th Edition, John Wiley & Sons, 1997.[10] F-35 Lightning II Program, Joint Strike Fighter Program, http://www.jsf.mil.[11] “The Life of Henry Ford,” The Henry Ford, http://thehenryford.org/exhibits/hf/chrono.asp.[12] “Quality Assurance and Quality Control,” American Society forQuality, http://www.asq.org/learn-about-quality/quality-assurance-quality-control/overview/overview.html.[13] “Walter A. Shewhart,” American Society for Quality, http://www.asq.org/about-asq/who-we-are/bio_shewhart.html.[14] “747 Model Summary Through October 2008,” Boeing,http://active.boeing.com/commercial/orders/displaystandardreport.cfm?cboCurrentModel=747&optReportType=AllModels&cboAllModel=747&ViewReportF=View+Report[15] “B-52 Stratofortress,” Air Force Link, http://www.af.mil/factsheets/factsheet.asp?id=83.

techsolutions 9

Figure 5. F-22 Raptor Assembly. Photo Courtesy of US Air Force




AMMTIAC DirectoryTECHNICAL MANAGER/CORDr. Khershed CooperNaval Research LaboratoryCode 63544555 Overlook Ave, SWWashington, DC 20375202.767.0181Email: [email protected]

AMMTIAC DEPUTY DIRECTORChristian E. Grethlein, P.E.201 Mill StreetRome, NY 13440-6916315.339.7009, Fax: 315.339.7107Email: [email protected]

MATERIALS TECHNICAL DIRECTORJeffrey D. Guthrie201 Mill StreetRome, NY 13440-6916315.339.7058, Fax: 315.339.7107Email: [email protected]

DEFENSE TECHNICAL INFORMATION CENTER(DTIC) POCGlenda Smith, DTIC-I8725 John J. Kingman Road, Ste 0944Ft. Belvoir, VA 22060-6218703.767.9127, Fax: 703.767.9174Email: [email protected]

CONTRACTS FACILITATORJudy E. Tallarino201 Mill StreetRome, NY 13440-6916315.339.7092, Fax: 315.339.7107Email: [email protected]

MANUFACTURING TECHNICAL DIRECTORChristian E. Grethlein, P.E.201 Mill StreetRome, NY 13440-6916315.339.7009, Fax: 315.339.7107Email: [email protected]

AMMTIAC DIRECTORMicheal J. Morgan201 Mill StreetRome, NY 13440-6916937.431.9322 x103, Fax: 315.339.7107Email: [email protected]

TECHNICAL INQUIRY SERVICES MANAGERRichard A. Lane201 Mill StreetRome, NY 13440-6916315.339.7097, Fax: 315.339.7107Email: [email protected]

NON-DESTRUCTIVE EVALUATIONAND TESTING TECHNICAL DIRECTORDr. George A. Matzkanin3096 Stevens Circle SouthErie, CO 80516303.926.0582, Fax: 303.774.0652Email: [email protected]

answers materials, manufacturing,and testing questions

C A L L : 315.339.7090

E M A I L : amm t i a c@a l i o n s c i e n c e . c om

O R

V I S I T : http : //amm t i a c . a l i o n s c i e n c e . c om/expe r t s

AMMTIAC

For a listing of upcoming materials, manufacturing & testing related events, please visit our website:http://ammtiac.alionscience.com/calendar



Prsrt StdUS Postage

PaidUtica, NY

Permit No. 566

AMMTIAC201 Mill StreetRome, NY 13440-6916

Please update and verify your subscription information at: http://ammtiac.alionscience.com/certify

Free Subscriptionhttp://ammtiac.alionscience.com/subscribe/

Inquiry Line/Ask the Experts315.339.7090



Documents

AMMTIAC Quarterly, Vol. 3, No. 3 - Antimicrobial Titania … · oxide coated polymer nanofibers with a diameter on the order of 100 nm and a coating thickness ranging from 20 to 80