Research Article Corrosion Response of Ti6Al4V and Ti15Mo ...downloads.hindawi.com/journals/ijc/2013/739841.pdf · Corrosion Response of Ti6Al4V and Ti15Mo Dental Implant Alloys in

Hindawi Publishing CorporationInternational Journal of CorrosionVolume 2013 Article ID 739841 7 pageshttpdxdoiorg1011552013739841

Research ArticleCorrosion Response of Ti6Al4V and Ti15Mo Dental ImplantAlloys in the Presence of Listerine Oral Rinse

Rahul Bhola1 Charu Chandra2 Faisal M Alabbas13 Sukumar Kundu14

Brajendra Mishra1 and David L Olson1

1 Department of Metallurgical and Materials Engineering Colorado School of Mines Golden CO 80401 USA2Department of Chemistry University of Delhi Delhi 110007 India3 Department of Inspection Saudi Aramco Dhahran 31311 Saudi Arabia4Department of Metallurgy and Materials Engineering Bengal Engineering and Science University Shibpur Howrah 711103 India

Correspondence should be addressed to Rahul Bhola bholarahulgmailcom

Received 18 July 2013 Accepted 7 October 2013

Academic Editor Sebastian Feliu

Copyright copy 2013 Rahul Bhola et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The influence of a commonly used antibacterial mouth rinse Listerine on the corrosion behavior of one of the commonly usedtitanium alloys Ti6Al4V (two-phase structure ie 120572 and 120573) and a newer Ti15Mo (single 120573 phase) in normal saline solution hasbeen investigated using electrochemical techniques Interfacial electrochemical changes occurring at the oxide-solution interfacehave been analysed using EIS circuit modeling Listerine acts as a corrosion inhibitor for Ti15Mo alloy and a corrosion promoterfor Ti6Al4V alloy

1 Introduction

Listerine is a commonly used mouth rinse with antiplaqueanticaries and antibacterial properties It is used in severaldental applications following periodontal procedures androutine oral prophylaxis It was awarded theAmericanDentalAssociationrsquos seal of recognition in 1987 for its clinical efficacyin plaque control and gingival improvement [1]

Listerine antiseptic developed by Warner-Lambert wasthe first over-the-counter mouth rinse [2] Listerine con-tains different essential oils which are phenolics such asthymol eucalyptol menthol and methyl salicylate and areknown to retard plaque buildup and reduce gingivitis [3ndash10] Thymol eucalyptol and menthol are known to possessproven antibacterial activity and are found in thyme (Thymusvulgaris) eucalyptus (Eucalyptus globulus) and peppermint(Mentha piperita) respectively Methyl salicylate has anti-inflammatory activity and is found in meadowsweet (Fil-ipendula ulmaria) and willow (Salix spp) [2] The effect ofListerine on plaque was ascribed to its bactericidal propertiesrelated to the alteration of bacterial cell wall which has beenwell documented in vitro and in vivo [11ndash15]

A newly inserted prosthesis and various surroundingtissues may get exposed to Listerine from minutes to daysdepending upon the therapy performed and the local andsystemic patient factors It is thus important to understandthe effect of Listerine on the electrochemical and corrosionbehavior of titanium alloys in order to predict treatmentprognosis Cestarolli et al [16] have compared the effect ofmouthwashes including Listerine and a simulated body fluidon the corrosion behavior of an Fe-Cr-Ni alloyThe corrosionresistance of this alloy was the highest in the presence of Lis-terine mouthwash However the present study simulates theuse of Listerine as an oral prophylactic rinse in other wordsthe condition when the concentration of saliva gets altereddue to the presence of Listerine in the mouth The effect ofthis normal saline-Listerine solution has thus been exploredon the behavior of titanium alloys when used as prosthesesin patients The conventional dental implants comprise theTi6Al4V alloy but owing to its higher modulus of elasticityand thereby creating a greater modulus mismatch with thebone (stress shielding effect) newer beta alloys Ti15Mo withlower elastic modulus are being developed for use as implantsin oral cavity

2 International Journal of Corrosion

25120583m

(a)

25120583m

(b)

Figure 1 Microstructure of the titanium alloys (a) Ti6Al4V (b) Ti15Mo

The aim of this investigation is to explore the influenceof Listerine addition on the electrochemical behavior ofTi6Al4V (two phases structure ie 120572 and 120573) and Ti15Mo(single 120573 phase) alloys in normal saline

2 Materials and Methods

21 Materials Preparation Titanium alloy samples Ti6Al4V(01 C 02 Fe 0015 H 003 N 02 O 6 Al 4V and 8945 Ti) and Ti15Mo (005 C 01 Fe 0015H 001 N 015 O 15 Mo and 8467 Ti) providedby ATI Wahchang (Albany USA) were used for the presentinvestigation The specimens were finished with differentgrades of SiC grit papers up to 2400 grit polished to a mirrorfinish and finally degreased with acetone

Normal saline solution (sodium chloride inj USP HOS-PIRA composition 526 gLminus1 sodium chloride 222 gLminus1anhy sodium acetate 502 gLminus1 sodium gluconate 037 gLminus1potassium chloride and 03 gLminus1 magnesium chloride hex-ahydrate) having pH 66 was used to make two differentconcentrations of Listerine

Listerine solution (LISTERINE Johnson amp Johnson com-position 0092 eucalyptol 0042 menthol 006 methylsalicylate 0064 thymol 216 alcohol (ethanol) sorbitolpoloxamer 407 benzoic acid zinc chloride sucralose sodiumbenzoate and water) was used for the preparation of 25 and50 solutions respectively

22 Microstructural Measurements The metal specimenswere degreased dried and mounted in bakelite resinMechanical grinding was done with SiC papers on a watercooled grinding stage Polishing was performed using gradu-ally decreasing sizes of diamond abrasive from 6120583m to 1 120583mand finally using an alumina abrasive (with decreasing parti-cle size from 050120583m to 025 120583m) and cold saturated hydrousoxalic acid suspension on a short circular velvet cloth Thespecimens were washed in deionized water and ethanol andair-dried before etching An etchant commonly known as theKrollrsquos reagent a hydrous solution comprising 2mLHF (40conc) and 6mL HNO

3

(65 conc) in 100mL H2

O (deion-ized) was used for etching The microstructure obtainedwas determined using Olympus stereo microscope

23 Electrochemical Measurements A three-electrode cellassembly consisting of titaniumalloy as theworking electrode(WE) platinumwire as the counter electrode (CE) and a sat-urated calomel electrode as the reference electrode (RE) wasused for the electrochemical measurements Electrochemicaltesting was performed in a closed system at 298K tempera-ture under naturally aerated conditions using a PARPotentio-stat 273A coupled to a PAR FRA 1255 using ZPlotCorrwaresoftware The sequence of electrochemical techniques hasbeen described below

Electrochemical Impedance Spectroscopy (EIS) Impedancemeasurements were performed at the open circuit potential(OCP) at 1 hour and 24 hours of immersion The frequencysweep was applied from 105 to 10minus2Hzwith the AC amplitudeof 10mV

Potentiodynamic Polarization Potentiodynamic polarizationmeasurements were performed at 24 hours of immersion bypolarizing the working electrode from an initial potential ofminus500mV versus OCP upto a final potential of 2V versus REA scan rate of 1mVs was used for the polarization sweep

3 Results and Discussion

The optical micrographs of annealed Ti6Al4V and Ti15Moalloys are shown in Figure 1 The microstructure of Ti6Al4Valloy primarily consists of white large grains of the 120573 phasewhich is primarily a body center cubic crystal structure(BCC) along with small volume fraction of 120572 phase at thegrain junctions primarily hexagonal close pack structure(HCP) On the other hand the microstructure of Ti15Moalloy primarily consists of large equiaxed grains of the120573phase(BCC) along with twin boundary

The EIS data of Ti6Al4V and Ti15Mo alloys in normalsaline solution in the absence and presence of Listerine wasfound to fit the equivalent circuit models shown in Figure 2where 119877

119904

is the solution resistance 119877ct is the charge transferresistance119882 is theWarburg impedance due to diffusion andCPE is the constant phase element for the capacitance of thepassive oxide film The impedance of the CPE is given by

119885 (CPE) = [119876(119895120596)119899]minus1

(1)

International Journal of Corrosion 3

Rs

CPE

Rct

(a)

Rs

CPE

wRct

(b)

Figure 2 Circuit models used to fit EIS data for Ti6Al4V and Ti15Mo alloys

minus750000

minus500000

minus250000

0

0250000

250000 500000 750000 1000000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)

Ti64-normal salineTi64-normal saline + 25 LisTi64-normal saline + 50 Lis

(a)

1h

Frequency (Hz)10

010

minus110

minus210

110

1

102

102

103

103

104

104

105

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

105

106

minus100

minus75

minus50

minus25

0

25

2120579

(deg

)|Z|(Ω

cm2)


(b)

24hminus750000

minus500000

minus250000

0

0250000

250000 500000 750000 1000000

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

Frequency (Hz)10

010

minus110

minus210

110

1

102

102

103

103

104

104

105

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

105

106

minus100

minus75

minus50

minus25

0

25

24h

|Z|(Ω

cm2)

2120579

(deg

)


(d)

Figure 3 Impedance plots (Bode amp Nyquist) for Ti6Al4V alloy in normal saline solution in the absence and presence of 25 and 50Listerine at 1 h ((a) and (b)) and 24 h ((c) and (d)) of immersion


Table 1 EIS parameters for Ti6Al4V alloy in normal saline solution in the absence and presence of 25 and 50 Listerine at 1 h and 24 h ofimmersion

System 119877119904

(Ω cm) 119877ct (Ω cm2) 119876 (S cmminus2 (s radminus1)119899) 119899

Normal saline (1 h) 1920 686 times 105

301 times 10minus5 0919

Normal saline + 25 Lis (1 h) 1924 413 times 105










where119876 is the constant of CPE 120596 is the angular frequency inrad 119904minus1 and 119899 is the exponential termwhich can vary between1 for pure capacitance and 0 for a pure resistor [17] 119899 is ameasure of surface heterogeneity and the lower is its valuethe higher is the surface roughening of the metalalloy [18]Diffusional impedance is characterized by three parameters119882(119877)119882(119879) and119882(119875)119882(119877) corresponds to the length ofdiffusion impedance 119882(119879) is the diffusion time constantand119882(119875) is the phase factor (0 lt 119882(119875) lt 1)

Figure 3 shows the impedance plots for Ti6Al4V alloy andthe corresponding impedance parameters evaluated from thecircuit modeling have been listed in Table 1

Ti6Al4V alloy fits the circuit model shown in Figure 2(a)The alloy exhibits the presence of a charge transfer elec-trochemical reaction in normal saline solution and alsoupon Listerine additions At both 1 hour and 24 hours ofimmersion both concentrations of Listerine show a decreasein the charge transfer resistance of the alloy with the higherconcentration producing a large decrease The heterogeneityparameter 119899 shows a decrease in the same order implyingthat the surface becomes increasingly rough with increasedadditions of ListerineThese observations suggest that Lister-ine interferes with oxide growth in solution over the surfaceof Ti6Al4V alloy and rather brings about the dissolution ofthe oxide In addition the solution resistance has increasedupon addition of Listerine to normal saline and the increase ishigher for higher Listerine concentrations which is due to thecontribution from organic compounds present in Listerine

Moreover in each of these solutions the charge transferresistance has increased from 1 hour to 24 hours of immer-sion even in the presence of ListerineThe increase in119877ct withimmersion time is however less in case of 50 Listerinecompared to the other two solutions

Figure 4 shows the potentiodynamic polarization plotsfor Ti6Al4V alloy at 24 hours of immersion and the corre-sponding polarization parameters have been listed in Table 2It appears from the 119868corr values that 25 Listerine producesonly a small increase in the corrosion rate compared to 50ListerineThese results support the results obtained fromEISThe anodic current densities in the presence of Listerine donot differ much from normal saline solution near 119864corr but50 Listerine shows an increase in cathodic current densitiesnear 119864corr which causes a higher overall corrosion rate in thepresence of 50 Listerine The cathodic and anodic slopeshave however not changed upon Listerine addition whichimplies that the cathodic and anodic reaction mechanismoccurring over the Ti6Al4V surface has not been altered

Table 2 Polarization parameters for Ti6Al4V alloy in normal salinesolution in the absence and presence of 25 and 50 Listerine

System 119864corr (V versus SCE) 119868corr (A cmminus2)Normal saline minus0267 120 times 10

minus8

Normal saline + 25 Lis minus0343 167 times 10minus8


20

15

10

05

0

minus05

minus10

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4

Current density (Acm2)


Pote

ntia

l (V

vers

us S

CE)

Figure 4 Potentiodynamic polarization plot for Ti6Al4V alloy innormal saline solution in the absence and presence of 25 and 50Listerine at 24 h of immersion

Figure 5 shows the impedance plots for Ti15Mo alloyand the corresponding impedance parameters deduced fromcircuit modeling are given in Table 3

Ti15Mo alloy in normal saline solution and in the pres-ence of 25 Listerine shows the presence of charge transferas well as mass transfer controlled electrochemical reactionsat both 1 hour and 24 hours of immersion However incase of 50 Listerine containing solution the alloy showsthe presence of only a charge transfer reaction At bothimmersion times the charge transfer resistance increasesin the presence of Listerine and the increase is more forthe higher Listerine concentration The overall polarizationresistance of Ti15Mo alloy in the presence of Listerine isincreased except for a decrease at 1 hour in the presence of25 Listerine In contrast to the overall trend at both


Table 3 EIS parameters for Ti15Mo alloy in normal saline solution in the absence and presence of 25 and 50 Listerine at 1 h and 24 h ofimmersion

System 119877119904

(Ω cm) 119877ct (Ω cm2) 119882(119877) (Ω cm2) 119882(119875) 119882(119879) (s) 119877

119901

(Ω cm2) 119876 (S cmminus2 (s radminus1)119899) 119899Normal saline (1 h) 767 174 times 10

3

473 times 104 0634 5407 490 times 10

4



374 times 104 0619 5920 392 times 10

4


Normal saline + 25 Lis (24 h) 2941 778 times 104 mdash mdash mdash 778 times 10

4



402 times 104 0632 5332 416 times 10

4



715 times 104 0681 1824 730 times 10

4



5


119877

119901

is the polarization resistance of Ti15Mo alloy (119877ct +119882(119877))

minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)

Ti15Mo-normal salineTi15Mo-normal saline + 25 LisTi15Mo-normal saline + 50 Lis

(a)

1h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

0

25

|Z|(Ω

cm2)

2120579

(deg

)


(b)

minus62500

minus75000

minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000 100000

24h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

24h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

25

0

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

|Z|(Ω

cm2)

2120579

(deg

)


(d)

Figure 5 Impedance plots (Bode ampNyquist) for Ti15Mo alloy in normal saline solution in the absence and presence of 25 and 50 Listerineat 1 h ((a) and (b)) and 24 h ((c) and (d)) of immersion


Table 4 Polarization parameters for Ti15Mo alloy in normal salinesolution in the absence and presence of 25 and 50 Listerine


minus7



20

15

10

05

0

minus05

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



minus10

Pote

ntia

l (V

vers

us S

CE)

Figure 6 Potentiodynamic polarization plot for Ti15Mo alloy innormal saline solution in the absence and presence of 25 and 50Listerine at 24 h of immersion

immersion hours for both concentrations this observationcan be ignored

With the increase in immersion time from 1 hour to24 hours the overall polarization resistance of Ti15Mo alloydecreases in normal saline but in the presence of bothListerine concentrations it shows an increase with time

These results show that the corrosion resistance of Ti15Moalloy is improved upon Listerine addition in normal salinesolution In other words Listerine acts as a corrosioninhibitor for Ti15Mo alloy under these conditions

Figure 6 illustrates the potentiodynamic polarizationcurves for Ti15Mo alloy at 24 hours of immersion and thecorresponding polarization parameters have been given inTable 4 The 119868corr values have decreased in the presence ofListerine which suggests the corrosion inhibition of Ti15Moalloy by Listerine in normal saline solution Furthermorethe polarization plots for Ti15Mo alloy illustrate a changein cathodic and anodic slopes upon Listerine addition tonormal saline solution which indicates that Listerine altersthe reaction mechanism of the cathodic and anodic reactionsoccurring on the Ti15Mo surface by adsorption or blockingof the active sites on the alloy surface It is possible that thecorrosion inhibition effect of Listerine for Ti15Mo alloy is dueto the influence of the organic compounds present in Lister-ine such as sodium benzoate benzoic acid methyl salicylatesorbitol menthol and thymol which are known for their

inhibition action [19ndash24] On the contrary Ti6Al4V alloyinvestigated in this study has shown higher corrosion rates inthe presence of Listerine Corrosion is a property of the sys-temwhich includes both thematerial under investigation andits environment Corrosivity of an environment will dependupon the material and the corrodibility of a material willdepend upon the environment Though Ti15Mo alloy showsa higher corrosion rate over the Ti6Al4V alloy its corrosionrate (sim5 times 10minus3mpy) belongs to the outstanding corrosionresistance category as classified by Fontana [25] and is lesslikely to be detrimental to the host tissue Moreover being a120573-alloy it has a lower modulus mismatch with bone com-pared to themixed Ti6Al4V alloy and remains a better choicefor use as an implant

4 Conclusions

Antiplaque and antimicrobial action of Listerine is wellacknowledged in the clinical communityThe titanium alloysinvestigated in normal saline solution in this study Ti6Al4V(120572 and 120573 phases) and Ti15Mo (120573 phase) exhibit variablecorrosion behavior in the presence of Listerine with Ti6Al4Valloy showing an increase in corrosion rate and Ti15Moshowing a decrease in corrosion rate upon Listerine addition

Appropriate care must hence be taken during alloyselection for prosthetic applications in a specific clinicalsituation as the increased corrosion and release of byproductsinto the surrounding tissues in the presence of antibacterialmouthwashes under certain conditions could be detrimentaland bring about a mild to severe adverse reaction which mayfinally lead to treatment failure

A corrosion inhibitor could be used additionally to pre-vent dissolution of the prosthesis in the presence of mouth-washes causing corrosion of alloys

References

[1] W C Waggoner Clinical Safety and Efficacy Testing of Cos-metics vol 8 of Cosmetic science and technology series MarcelDekker New York NY USA 1990

[2] L A Cindy The Antibiotic Alternative The Natural Guide toFighting Infection and Maintaining a healthy Immune SystemHealing Arts Press 2000

[3] J Fornell Y Sundin and J Lindhe ldquoEffect of Listerine on dentalplaque and gingivitisrdquo Scandinavian Journal of Dental Researchvol 83 no 1 pp 18ndash25 1975

[4] J M Gordon I B Lamster and M C Seiger ldquoEfficacy oflisterine antiseptic in inhibiting the development of plaque andgingivitisrdquo Journal of Clinical Periodontology vol 12 no 8 pp697ndash704 1985

[5] P Axelsson and J Lindhe ldquoEfficacy ofmouthrinses in inhibitingdental plaque and gingivitis in manrdquo Journal of Clinical Peri-odontology vol 14 no 4 pp 205ndash212 1987

[6] S Mankodi N M Ross and K Mostler ldquoClinical efficacy oflisterine in inhibiting and reducing plaque and experimentalgingivitisrdquo Journal of Clinical Periodontology vol 14 no 5 pp285ndash288 1989

[7] L G DePaola C D Overholser T F Meiller G E Minahand C Niehaus ldquoChemotherapeutic inhibition of supragingival


dental plaque and gingivitis developmentrdquo Journal of ClinicalPeriodontology vol 16 no 5 pp 311ndash315 1989

[8] C D Overholser T F Meiller L G DePaola G E Minahand C Niehaus ldquoComparative effects of 2 chemotherapeuticmouthrinses on the development of supragingival dental plaqueand gingivitisrdquo Journal of Clinical Periodontology vol 17 no 8pp 575ndash579 1990

[9] N M Ross S M Mankodi S M Mostler C H Charles andL L Bartels ldquoEffect of rinsing time on antiplaque-antigingivitisefficacy of listerinerdquo Journal of Clinical Periodontology vol 20no 4 pp 279ndash281 1993

[10] M Brecx E Brownstone L MacDonald S Gelskey andM Cheang ldquoEfficacy of Listerine Meridol and chlorhexidinemouthrinses as supplements to regular tooth-cleaning mea-suresrdquo Journal of Clinical Periodontology vol 19 no 3 pp 202ndash207 1992

[11] J Swarbrick and J C Boylan Encyclopedia of PharmaceuticalTechnology vol 2 Marcel Dekker New York NY USA 2002

[12] N M Ross C H Charles and S S Dills ldquoLong-term effects oflisterine antiseptic on dental plaque and gingivitisrdquo Journal ofClinical Dentistry vol 1 no 4 pp 92ndash95 1989

[13] S Jenkins M AddyWWade and R G Newcombe ldquoThemag-nitude and duration of the effects of somemouthrinse productson salivary bacterial countsrdquo Journal of clinical periodontologyvol 21 no 6 pp 397ndash401 1994

[14] L G DePaola G E Minah C Daniel Overiiolser et alldquoEffect of an antiseptic mouthrinse on salivary microbiotardquoTheAmerican Journal of Dentistry vol 9 no 3 pp 93ndash95 1996

[15] P PanM L Barnett J Coelho C Brogdon andMB FinneganldquoDetermination of the in situ bactericidal activity of an essentialoil mouthrinse using a vital stain methodrdquo Journal of ClinicalPeriodontology vol 27 no 4 pp 256ndash261 2000

[16] D T Cestarolli V A Alves and L A Da Silva ldquoIn situ and exsitu characterization of a Fe-Cr-Ni alloy in mouthwashes andHankrsquos solutionrdquo Chemical Papers vol 62 no 3 pp 326ndash3282008

[17] C H Hsu and F Mansfeld ldquoConcernng the conversion of theconstant phase element parameter Y0 into a capacitancerdquoCorrosion vol 57 no 9 pp 747ndash748 2001

[18] S Chongdar G Gunasekaran and P Kumar ldquoCorrosion inhi-bition of mild steel by aerobic biofilmrdquo Electrochimica Acta vol50 no 24 pp 4655ndash4665 2005

[19] P Agarwal and D Landolt ldquoEffect of anions on the efficiencyof aromatic carboxylic acid corrosion inhibitors in near neutralmedia experimental investigation and theoretical modelingrdquoCorrosion Science vol 40 no 4-5 pp 673ndash691 1998

[20] F Mansfeld Corrosion Mechanisms vol 139 Marcel DekkerNew York NY USA 1987

[21] P Premkumar K Kannan andMNatesan ldquoEvaluation ofmen-thol as vapor phase corrosion inhibitor for mild steel in NaClenvironmentrdquo Arabian Journal for Science and Engineering vol34 no 2 pp 71ndash79 2009

[22] L J Aljinovic and V Gotovac ldquoAdsorption and corrosion inhi-bition properties of thymolrdquo Journal of Applied Electrochemistryvol 15 no 5 pp 767ndash770 1985

[23] R K Dinnappa and S M Mayanna ldquoBenzoic acid and substi-tuted benzoic acids as interfacial corrosion inhibitors for copperin HClO

4

rdquo Journal of Applied Electrochemistry vol 11 no 1 pp111ndash116 1981

[24] R T Ignash I E Zarinya and B A Berge ldquoSynthesis and studyof polyol borates as corrosion inhibitors for steel and nonferrous

metalsrdquo Russian Journal of Applied Chemistry vol 82 no 12 pp2146ndash2150 2009

[25] MG FontanaCorrosion Engineering McGraw-Hill NewYorkNY USA 3rd edition 1986

Submit your manuscripts athttpwwwhindawicom

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Smart Materials Research



MetallurgyJournal of


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Nano

materials


Journal ofNanomaterials


25120583m

(a)

25120583m

(b)

Figure 1 Microstructure of the titanium alloys (a) Ti6Al4V (b) Ti15Mo

The aim of this investigation is to explore the influenceof Listerine addition on the electrochemical behavior ofTi6Al4V (two phases structure ie 120572 and 120573) and Ti15Mo(single 120573 phase) alloys in normal saline

2 Materials and Methods

21 Materials Preparation Titanium alloy samples Ti6Al4V(01 C 02 Fe 0015 H 003 N 02 O 6 Al 4V and 8945 Ti) and Ti15Mo (005 C 01 Fe 0015H 001 N 015 O 15 Mo and 8467 Ti) providedby ATI Wahchang (Albany USA) were used for the presentinvestigation The specimens were finished with differentgrades of SiC grit papers up to 2400 grit polished to a mirrorfinish and finally degreased with acetone

Normal saline solution (sodium chloride inj USP HOS-PIRA composition 526 gLminus1 sodium chloride 222 gLminus1anhy sodium acetate 502 gLminus1 sodium gluconate 037 gLminus1potassium chloride and 03 gLminus1 magnesium chloride hex-ahydrate) having pH 66 was used to make two differentconcentrations of Listerine

Listerine solution (LISTERINE Johnson amp Johnson com-position 0092 eucalyptol 0042 menthol 006 methylsalicylate 0064 thymol 216 alcohol (ethanol) sorbitolpoloxamer 407 benzoic acid zinc chloride sucralose sodiumbenzoate and water) was used for the preparation of 25 and50 solutions respectively

22 Microstructural Measurements The metal specimenswere degreased dried and mounted in bakelite resinMechanical grinding was done with SiC papers on a watercooled grinding stage Polishing was performed using gradu-ally decreasing sizes of diamond abrasive from 6120583m to 1 120583mand finally using an alumina abrasive (with decreasing parti-cle size from 050120583m to 025 120583m) and cold saturated hydrousoxalic acid suspension on a short circular velvet cloth Thespecimens were washed in deionized water and ethanol andair-dried before etching An etchant commonly known as theKrollrsquos reagent a hydrous solution comprising 2mLHF (40conc) and 6mL HNO

3

(65 conc) in 100mL H2

O (deion-ized) was used for etching The microstructure obtainedwas determined using Olympus stereo microscope

23 Electrochemical Measurements A three-electrode cellassembly consisting of titaniumalloy as theworking electrode(WE) platinumwire as the counter electrode (CE) and a sat-urated calomel electrode as the reference electrode (RE) wasused for the electrochemical measurements Electrochemicaltesting was performed in a closed system at 298K tempera-ture under naturally aerated conditions using a PARPotentio-stat 273A coupled to a PAR FRA 1255 using ZPlotCorrwaresoftware The sequence of electrochemical techniques hasbeen described below

Electrochemical Impedance Spectroscopy (EIS) Impedancemeasurements were performed at the open circuit potential(OCP) at 1 hour and 24 hours of immersion The frequencysweep was applied from 105 to 10minus2Hzwith the AC amplitudeof 10mV

Potentiodynamic Polarization Potentiodynamic polarizationmeasurements were performed at 24 hours of immersion bypolarizing the working electrode from an initial potential ofminus500mV versus OCP upto a final potential of 2V versus REA scan rate of 1mVs was used for the polarization sweep

3 Results and Discussion

The optical micrographs of annealed Ti6Al4V and Ti15Moalloys are shown in Figure 1 The microstructure of Ti6Al4Valloy primarily consists of white large grains of the 120573 phasewhich is primarily a body center cubic crystal structure(BCC) along with small volume fraction of 120572 phase at thegrain junctions primarily hexagonal close pack structure(HCP) On the other hand the microstructure of Ti15Moalloy primarily consists of large equiaxed grains of the120573phase(BCC) along with twin boundary

The EIS data of Ti6Al4V and Ti15Mo alloys in normalsaline solution in the absence and presence of Listerine wasfound to fit the equivalent circuit models shown in Figure 2where 119877

119904

is the solution resistance 119877ct is the charge transferresistance119882 is theWarburg impedance due to diffusion andCPE is the constant phase element for the capacitance of thepassive oxide film The impedance of the CPE is given by

119885 (CPE) = [119876(119895120596)119899]minus1

(1)


Rs

CPE

Rct

(a)

Rs

CPE

wRct

(b)


minus750000

minus500000

minus250000

0

0250000

250000 500000 750000 1000000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(a)

1h

Frequency (Hz)10

010

minus110

minus210

110

1

102

102

103

103

104

104

105

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

105

106

minus100

minus75

minus50

minus25

0

25

2120579

(deg

)|Z|(Ω

cm2)


(b)

24hminus750000

minus500000

minus250000

0

0250000

250000 500000 750000 1000000

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

Frequency (Hz)10

010

minus110

minus210

110

1

102

102

103

103

104

104

105

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

105

106

minus100

minus75

minus50

minus25

0

25

24h

|Z|(Ω

cm2)

2120579

(deg

)


(d)




System 119877119904





















minus8



20

15

10

05

0

minus05

minus10

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



Pote

ntia

l (V

vers

us S

CE)






System 119877119904

(Ω cm) 119877ct (Ω cm2) 119882(119877) (Ω cm2) 119882(119875) 119882(119879) (s) 119877

119901


3

473 times 104 0634 5407 490 times 10

4



374 times 104 0619 5920 392 times 10

4



4



402 times 104 0632 5332 416 times 10

4



715 times 104 0681 1824 730 times 10

4



5


119877

119901


minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(a)

1h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

0

25

|Z|(Ω

cm2)

2120579

(deg

)


(b)

minus62500

minus75000

minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000 100000

24h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

24h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

25

0

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

|Z|(Ω

cm2)

2120579

(deg

)


(d)





minus7



20

15

10

05

0

minus05

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



minus10

Pote

ntia

l (V

vers

us S

CE)







4 Conclusions




References


























4












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




Rs

CPE

Rct

(a)

Rs

CPE

wRct

(b)


minus750000

minus500000

minus250000

0

0250000

250000 500000 750000 1000000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(a)

1h

Frequency (Hz)10

010

minus110

minus210

110

1

102

102

103

103

104

104

105

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

105

106

minus100

minus75

minus50

minus25

0

25

2120579

(deg

)|Z|(Ω

cm2)


(b)

24hminus750000

minus500000

minus250000

0

0250000

250000 500000 750000 1000000

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

Frequency (Hz)10

010

minus110

minus210

110

1

102

102

103

103

104

104

105

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

105

106

minus100

minus75

minus50

minus25

0

25

24h

|Z|(Ω

cm2)

2120579

(deg

)


(d)




System 119877119904





















minus8



20

15

10

05

0

minus05

minus10

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



Pote

ntia

l (V

vers

us S

CE)






System 119877119904

(Ω cm) 119877ct (Ω cm2) 119882(119877) (Ω cm2) 119882(119875) 119882(119879) (s) 119877

119901


3

473 times 104 0634 5407 490 times 10

4



374 times 104 0619 5920 392 times 10

4



4



402 times 104 0632 5332 416 times 10

4



715 times 104 0681 1824 730 times 10

4



5


119877

119901


minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(a)

1h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

0

25

|Z|(Ω

cm2)

2120579

(deg

)


(b)

minus62500

minus75000

minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000 100000

24h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

24h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

25

0

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

|Z|(Ω

cm2)

2120579

(deg

)


(d)





minus7



20

15

10

05

0

minus05

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



minus10

Pote

ntia

l (V

vers

us S

CE)







4 Conclusions




References


























4












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





System 119877119904





















minus8



20

15

10

05

0

minus05

minus10

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



Pote

ntia

l (V

vers

us S

CE)






System 119877119904

(Ω cm) 119877ct (Ω cm2) 119882(119877) (Ω cm2) 119882(119875) 119882(119879) (s) 119877

119901


3

473 times 104 0634 5407 490 times 10

4



374 times 104 0619 5920 392 times 10

4



4



402 times 104 0632 5332 416 times 10

4



715 times 104 0681 1824 730 times 10

4



5


119877

119901


minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(a)

1h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

0

25

|Z|(Ω

cm2)

2120579

(deg

)


(b)

minus62500

minus75000

minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000 100000

24h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

24h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

25

0

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

|Z|(Ω

cm2)

2120579

(deg

)


(d)





minus7



20

15

10

05

0

minus05

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



minus10

Pote

ntia

l (V

vers

us S

CE)







4 Conclusions




References


























4












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





System 119877119904

(Ω cm) 119877ct (Ω cm2) 119882(119877) (Ω cm2) 119882(119875) 119882(119879) (s) 119877

119901


3

473 times 104 0634 5407 490 times 10

4



374 times 104 0619 5920 392 times 10

4



4



402 times 104 0632 5332 416 times 10

4



715 times 104 0681 1824 730 times 10

4



5


119877

119901


minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000

1h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(a)

1h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

0

25

|Z|(Ω

cm2)

2120579

(deg

)


(b)

minus62500

minus75000

minus50000

minus37500

minus25000

minus12500

0

125000 25000 50000 75000 100000

24h

Z998400(Ωcm2

)

Z998400998400(Ω

cm2)


(c)

24h

101

102

103

104

105

106

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

minus100

minus75

minus50

minus25

25

0

Frequency (Hz)10

010

minus110

minus210

110

210

310

410

5

|Z|(Ω

cm2)

2120579

(deg

)


(d)





minus7



20

15

10

05

0

minus05

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



minus10

Pote

ntia

l (V

vers

us S

CE)







4 Conclusions




References


























4












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials






minus7



20

15

10

05

0

minus05

10minus10

10minus9

10minus8

10minus7

10minus6

10minus5

10minus4



minus10

Pote

ntia

l (V

vers

us S

CE)







4 Conclusions




References


























4












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials





















4












CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



Documents

Research Article Corrosion Response of Ti6Al4V and Ti15Mo ...downloads.hindawi.com/journals/ijc/2013/739841.pdf · Corrosion Response of Ti6Al4V and Ti15Mo Dental Implant Alloys in