Nano-Borides and Silicide DispersedComposite Coating on AISI 304 Stainless

Steel by Laser-Assisted HVOF SprayDeposition

Prashant Sharma and Jyotsna Dutta Majumdar

(Submitted October 30, 2013; in revised form February 12, 2014)

The study concerned a detailed microstructural investigation of nano-borides (Cr2B and Ni3B) and nano-silicide (Ni2Si) dispersed c-nickel composite coating on AISI 304 stainless steel by HVOF spray depo-sition of the NiCrBSi precursor powder and subsequent laser surface melting. A continuous wave diodelaser with an applied power of 3 kW and scan speed of 20 mm/s in argon shroud was employed. Thecharacterization of the surface in terms of microstructure, microtexture, phases, and composition werecarried out and compared with the as-coated (high-velocity oxy-fuel sprayed) surface. Laser surfacemelting led to homogenization and refinement of microstructures with the formation of few nano-silicides of nickel along with nano-borides of nickel and chromium (Ni3B, Cr2B, and Cr2B3). A detailedmicrotexture analysis showed the presence of no specific texture in the as-sprayed and laser-meltedsurface of Cr2B and Ni3B phases. The average microhardness was improved to 750-900 VHN as com-pared to 250 VHN of the as-received substrate. Laser surface melting improved the microhardnessfurther to as high as 1400 VHN due to refinement of microstructure and the presence of silicides.

Keywords HVOF spraying, laser melting, microhardness,microstructure, nano-boride, nano-silicide

1. Introduction

Laser, as a source of monochromatic and coherentradiation, may be applied for the modification of micro-structure and/or composition of the near surface region ofcomponent (Ref 1, 2). High-velocity oxy-fuel coating(HVOF) is a thermal spray deposition technique, where theheat generated through the burning of oxy-fuel mixture(flame of oxygen and liquid petroleum gas) is used formelting of precursor powders and subsequently sprayedover the substrate at a velocity higher than the velocity ofsound (>600 m/min) (Ref 3). Development of dense coat-ing (>97% theoretical density) and formation of refined/metastable microstructure are the notable advantagesassociated with the HVOF spray deposition (Ref 3). How-ever, the presence of fine micro-porosities and thick inter-splat boundary gaps cause problems for the application ofthe coated component in harsh environment like aggressivecorrosive media and impact loading. In the past, HVOFspraying has been successfully applied on steel substrate to

improve its wear and corrosion resistance properties(Ref 3-5). In an earlier attempt, hard and wear resistantnano-borides (of chromium, Cr2B; and nickel, Ni3B)-dispersed composite coating (in c-Ni matrix) was developedon AISI 304 stainless steel by HVOF spray deposition ofNiCrBSi (Ref 6). Though there was a substantial enhance-ment in microhardness (750-945 VHN), however, a verylarge residual compressive stress was introduced in thecoated surface (�235 MPa). Moreover, the presence of asharp interface and porosities (3%) was observed on thecoated surface. In the past, laser surface alloying/claddinghas been applied to develop NiCrBSi coating and boride-dispersed coatings on different substrates to improve itswear and corrosion resistance (Ref 7-11).

Laser-assisted HVOF spraying is a hybrid process, wherea coating is developed by high-velocity oxyfuel spraying andsubsequently melting with laser beam to develop a cladlayer on the surface with a strong bonding at the inter-face—resulting in cladding (Ref 12). In the present study, adetailed characterization of nano-borides (Cr2B and Ni3B)and nano-silicide (Ni2Si) dispersed c-nickel compositecoating on AISI 304 stainless steel has been undertaken bylaser-assisted HVOF spray deposition of NiCrBSi.

2. Experimental

2.1 HVOF Spraying of NiCrBSi Coating

In the present study, stainless steel samples of dimen-sion: 20 mm 9 20 mm 9 5 mm were sand blasted (using

Prashant Sharma and Jyotsna Dutta Majumdar, Department ofMetallurgical and Materials Engineering, Indian Institute ofTechnology, Kharagpur, W.B. 721302, India. Contact e-mail:jyotsna@metal.iitkgp.ernet.in.

JTTEE5

DOI: 10.1007/s11666-014-0085-2

1059-9630/$19.00 � ASM International

Journal of Thermal Spray Technology

Peer

Revie

wed

Al2O3 particles of 10-25 lm particle size) and subjected tothermal spraying using high-velocity oxy-fuel sprayingtechnique (Hypojet-2700) using NiCrBSi (detailed com-position is summarized in Table 1) of particle size rangingfrom 45 to 60 lm as the feedstock material. Thermalspraying was conducted by melting the powder and sub-sequently fragmentation and deposition of the moltendroplets at a very high pressure using compressed air. Theparameters used for HVOF spray deposition are summa-rized in Table 2.

2.2 Laser Surface Melting of HVOF-SprayedNiCrBSi Coating

Following HVOF spraying, laser surface melting wascarried out with a 6 kW continuous wave diode laser(wavelength ~915 nm) delivered through an optical fiberhead mounted on a 6-axis Robot with a laser spot size of17 mm 9 2 mm (with top-hat intensity distribution) andabout 285 mm working distance between the laser headand the substrate using argon as shrouding environment.The parameters used for laser surface melting are sum-marized in Table 2.

2.3 Characterization of Coated Surface

After HVOF spraying and laser surface melting, themicrostructures of the coating (both the top surface andthe cross section) were characterized by scanning electronmicroscopy (SUPRA 40, Zeiss SMT AG, Germany) andhigh-resolution transmission electron microscopy (JEM-2100, JEOL, Japan). A detailed analysis of the phase andcomposition was carried out by x-ray diffraction technique(D8 Advances, Bruker AXS, Germany) and energy-dis-persive x-ray spectroscopy (EDS), respectively. Residualstress (both micro and macro) developed on the surface

was carefully measured by x-ray diffraction analysis usinga stress Goniometer for macro-stress (PW 3040/60, Pana-lytical X�pert Pro, Netherland) and peak broadeninganalysis using Scherrer�s formula (for micro-stress) (Ref 13).The detailed analysis of phase distribution and texturedistribution was carried out by electron back-scattereddiffraction (EBSD) technique attached to the scanningelectron microscopy. The EBSD pattern and image wasacquired using FLAMENCO HKL-Oxford Channel-5

Table 1 Summary of chemical composition of the pre-cursor powder NiCrBSi used for spraying

Chemical composition

Content Ni Cr B Si Fe

Wt.% 68.4 17 3.9 4.9 5.8

Table 2 Summary of process parameters of HVOF-spraying process and laser-melting process

HVOF spray system parameters

Process Fuel gas

Flow rate Pressure

Oxygen/fuelratio

Powder feedrate, g/minOxygen (SLPM(a)) Fuel gas (SLPM(a)) Oxygen (bar) Fuel gas (bar)

HVOF Spray LPG 250 60 10 7 4.3 25

Laser-processing parameters

Power, W Speed, mm/s Surface temperature, �C

3000 20 1100

(a) Flow rate unit ~ standard liter per min (slpm)

Fig. 1 Scanning electron micrographs of the top surface of (a)HVOF spray-deposited NiCrBSi alloy coating developed onAISI 304 stainless steel and the same following (b) laser surfacemelting

Journal of Thermal Spray Technology

Peer

Revie

wed

acquisition software with detector mounted with the dis-tance of 177.5 mm from the sample surface on SUPRAFESEM. All analyses were carried out at 20 kV acceler-ation voltage, aperture size of 120 lm, and high current.The microhardness of the coated surface (both on the topsurface and along the cross-sectional plane) was measuredby a Vickers microhardness tester (UHL-VMHT, Leica)using a 100 g applied load.

3. Results and Discussions

3.1 Microstructural Analysis

Figures 1(a) and (b) show scanning electron micro-graphs of the top surface of (a) HVOF spray-depositedand (b) laser-assisted HVOF spray-deposited NiCrBSialloy coating developed on AISI 304 stainless steel.Figure 1(a) shows the presence of featureless partiallyamorphous c-Ni matrix (labeled as 1), fine nano-struc-tured primary nickel borides (labeled as 2), eutectic mix-ture of nickel and nano-nickel boride (Ni3B) (labeled as3), and dispersion of nano-structured chromium boride(labeled as 4). Furthermore, the phase distribution is not

homogenous in the microstructure. The presence of thickinter-splat boundaries (labeled as 5) was also observed inthe microstructure. Furthermore, Fig. 1(a) also shows theformation two different boride precipitate rich zonesseparated by inter-splat boundaries (interface betweentwo solidified splats) with a thickness of 250 nm. Forma-tion of splats with different phase distributions is attrib-uted to local partitioning of elements during spraying. Thechromium-rich region causes formation of chromiumboride precipitates and chromium-depleted region com-bined with a low Si:B ratio caused formation of nickelborides in c-Ni matrix. Nano-structured nature of theprecipitates is attributed to the formation of coating byvery fine droplets sprayed over the substrate surface. Thegenesis of different boride formations has been explainedby Kanichi et al. (Ref 14) and Hemmati et al. (Ref 15).From Fig. 1(b) it is evident that laser surface meltingleads to further refinement of the microstructure with theuniform distribution of nano-sized chromium borides(labeled as 1) and nickel borides (labeled as 2) in therefined c-Ni matrix (labeled as 3).

Figures 2(a)-(d) show the transmission electronmicrographs of (a) HVOF-sprayed coating and the cor-responding selected area electron diffraction patterns of

Fig. 2 Transmission electron micrographs of (a) HVOF-sprayed coating and the corresponding selected area electron diffractionpatterns (b) zone 1, (c) zone 2, and (d) zone 3 as labeled in Fig. 6(a)

Journal of Thermal Spray Technology

Peer

Revie

wed

(b) zone 1, (c) zone 2, and (d) zone 3 as labeled inFig. 2(a). From Fig. 2(a) it may be noted that the micro-structure of HVOF spray-deposited surface consists of finedispersion of borides with particle size ranging from 3 to6 nm. A detailed analysis of the transmission electronmicrograph shows that there are two types of precipitateenriched region with a sharp contrast differences. Differ-ent regions are marked in Fig. 2(a) as 1, 2, and 3,respectively. The region marked as 1 is the partiallyamorphous matrix phase as evident from the selected areaelectron diffraction (SAED) pattern in Fig. 2(b). The darkprecipitate labeled as 2 is chromium boride (Cr2B) withorthorhombic crystal structure with [001] zone axis asevident from the selected area electron diffraction(SAED) pattern (cf. Fig. 2(c)). On the other hand, grey-colored precipitates are nickel boride (Ni3B) with anorthorhombic crystal structure with [411] zone axis(cf. Fig. 2(d)). The boride precipitates are mostly sphericalin shape and they are distributed uniformly in agglomer-ated fashion. Ni-Ni3B phase mixture is eutectic and par-tially amorphous and there is the presence of phaseboundaries between Ni, Cr2B, and Ni3B.

Figures 3(a)-(c) show the transmission electron micro-graphs of (a) laser-melted coating and the correspondingresolved lattice fringes of (b) zone 1 and (c) zone 2 of theregions labeled in Fig. 3(a). From Fig. 3(a) it may benoted that the microstructure is refined and homogenouswith the presence of chromium boride (Cr2B) and nickelboride (Ni3B) dispersed in c-Ni matrix. The presence ofchromium boride and nickel boride as separate precipi-tates in contrast to its presence in agglomerated form (asobserved in HVOF spray-deposited coating) is attributedto melting of coating by laser beam, its intermixing due toconvection dominated mass flow and rapid solidification.The average particle size of borides, however, varied from10 to 50 nm. The interphase boundary between chromiumboride (Cr2B) and nickel boride (Ni3B) are diffusive innature.

Figure 4 shows the x-ray diffraction profiles of the topsurface of HVOF spray-deposited NiCrBSi coating (plot 1)and the same after laser melting (plot 2). From Fig. 4 it

Fig. 4 X-ray diffraction patterns of HVOF-sprayed Ni basecoating (plot 1), and the same following laser surface melting(plot 2)

Fig. 3 Transmission electron micrographs of (a) laser-meltedcoating developed by HVOF spray deposition technique and thecorresponding resolved lattice fringes of zone 1 and zone 2 shownin Fig. 7(b) and (c), respectively, as labeled in Fig. 7(a)

Journal of Thermal Spray Technology

Peer

Revie

wed

may be noted that there are the presence of chromiumboride (Cr2B) and nickel boride (Ni3B) and c-Ni in themicrostructure. In addition, Ni was partially amorphous innature which is also evident from transmission electronmicroscopy (cf. Fig. 2). From Fig. 4 it may be noted thatdue to laser surface melting of HVOF spray-depositedcoating there is formation of borides of nickel and chro-mium (Ni3B, Cr2B, and Cr2B3) and silicides of nickel

(Ni2Si). Hence, it may be concluded that due to lasersurface melting, silicides and borides are the major con-stituents in the microstructure in contrast to c-Ni andborides (Ni3B and Cr2B) as observed in HVOF spray-deposited coating.

Figures 5(a)-(e) show the EBSD phase mapping(shown in Fig. 5b) of the band contrast image (shown inFig. 5a) and Kikuchi band patterns of (c) Ni3B, (d) Cr2B,

Fig. 5 Electron back-scattered diffraction (EBSD) mapping showing the (a) band contrast image and the corresponding (b) phasedistribution map and Kikuchi band patterns of (c) Ni3B (d), Cr2B, and (e) Cr2B3 corresponding to zone 1, zone 2, and zone 3 of Fig. 5(b),respectively

Journal of Thermal Spray Technology

Peer

Revie

wed

Fig. 6 Orientation mapping (OM) of (a) Cr2B, (b) Ni3B, and (c) Cr2B3 phases as shown in Fig. 5(b). The colors represent thecrystallographic orientation according to the inverse pole figure coloring (ipf) shown in legend of the corresponding figure

Fig. 7 Pole figures of (a) Cr2B and (b) Ni3B phases

Journal of Thermal Spray Technology

Peer

Revie

wed

and (e) Cr2B3 corresponding to zone 1, zone 2, and zone 3,shown in Fig. 5(b), respectively. From Fig. 5(b) it may benoted that there is the presence of both chromium boridesand nickel borides i.e., Cr2B, C2B3, and Ni3B in themicrostructure. Nickel is not visible in the mapping as it ispartially amorphous. The area fraction of Ni3B is maxi-mum in the microstructure (44.1%) followed by C2B(28.2%), Cr2B3 (27.7%), and Ni. Furthermore, the phasedistribution is not uniform in the microstructure.

Figures 6(a)-(c) show the orientation mapping of thedifferent phases in Fig. 5(b). Different colors represent thecrystallographic orientation according to the inverse polefigure coloring (ipf) shown in legend of the corresponding

figure. From Fig. 6(a) it may be noted that the grainslabeled as (1) are oriented along (110) plane, (2) along(010) plane, and (3) along (001) plane of Cr2B. In a fewlocations as marked by 4 and 5 there is orientation mis-match between the grains. White regions in Fig. 6(a)represent the absence of different phases except theidentified grains of the rest phases. Figure 6(b) also rep-resents that the few grains of Ni3B phase as labeled (1)oriented along (100), (2) (010), and (3) (001). The area offraction of mismatched grains for Ni3B phase is little lar-ger in comparison to Cr2B phase. Similarly, Fig. 6(c)shows the orientation of Cr2B3 phase along (1) (100), (2)(010), and grain (3) (001). The phase identification of Ni

Fig. 8 (a-f) Electron back-scattered diffraction (EBSD) mapping of (a) band contrast image and the corresponding (b) phase map andKikuchi band patterns of (c) Ni3B (d), Cr2B, (e) Cr2B3, and (f) Ni corresponding to zone 1, zone 2, zone 3, and zone 4, respectively, inFig. 8(b)

Journal of Thermal Spray Technology

Peer

Revie

wed

could not be undertaken due to its partial amorphizationin the microstructure and the absence of a distinct Kikuchipattern.

Figures 7(a) and (b) show the pole figures of(a) Cr2B and (b) Ni3B. From Fig. 7(a) it may beconcluded that there is no specific texture observed inCr2B phase. However, the strength of orientation ofgrains is maximum along {100} and {110} planes as

compared to {111} plane (cf. the corresponding poleplot). From Fig. 7(b) it may be noted that there is nospecific texture observed in Ni3B phase; however, thestrength of orientation of grains is maximum along {100}plane as compared to {110} and {111} (cf. the corre-sponding pole plot).

Figures 8(a)-(f) show the EBSD phase mapping (shownin Fig. 8b) and the corresponding Kikuchi band patterns

Fig. 9 Orientation mapping of (a) Cr2B, (b) Cr2B3, and (c) Ni3B phases in laser-melted sample; and (d) strain contour map

Journal of Thermal Spray Technology

Peer

Revie

wed

of (c) Ni3B (d), Cr2B, (e) Cr2B3, and (f) Ni correspondingto zone 1, zone 2, zone 3, and zone 4 shown in Fig. 8(b).From Fig. 8(b) it may be noted that there is an enrichedmass fraction of Ni3B (91.8%), in the microstructure. Thepresence of both Cr2B (4.1%) and C2B3 (3.3%) wasobserved whose distribution was uniform throughout. The

presence of very small fraction of Ni (0.85%) was alsonoticed in the microstructure.

Figures 9(a)-(c) show the orientation mapping of (a)Cr2B, (b) Cr2B3, and (c) Ni3B phases in laser-meltedsample as shown in Fig. 8(b). From Fig. 9(a) it may benoted that the grains of Cr2B labeled as (1) are indexed as

Fig. 10 Pole figures showing the character of (a) Cr2B, (b) Cr2B3, (c) Ni3B, and (d) Ni

Journal of Thermal Spray Technology

Peer

Revie

wed

(110) plane, (2) are indexed as (010) plane, and a fewlabeled as (3) are indexed as (001) plane. The degree ofmismatching grain is very low here. In Fig. 10(b) it is alsoseen that grains of Cr2B3 labeled as (1) are indexed as(100) plane, (2) are indexed as (010) plane, and (3) areindexed as (001) planes. On the other hand, the IPFmapping of Ni3B phase (Fig. 9(c)) grains labeled as (1) areindexed as (100) plane, labeled s (2) are indexed as (010)plane, and labeled as (3) are indexed as (001) planes.Figure 9(d) shows the strain contour in the microstructureof the laser-melted surface. From Fig. 9(d) it may be notedthat the lattice strain developed in the microstructureranges from 0.05 to 1.05%. Furthermore, the maximumnumbers of grains are subjected to a strain level of 0.35.Only a few grains possess a strain value as high as 1.05.

A detailed study of pole figures of laser-melted sampleare displayed in Fig. 10(a)-(d) showing the character for(a) Cr2B, (b) Cr2B3, (c) Ni3B, and (d) Ni. From Fig. 10(a)it may be concluded that there is no specific textureobserved in Cr2B phase. Figure 10(b) it may be noted thatthere is no specific texture observed in Cr2B3 phase;however, the strength of orientation of grains is maximumalong {100} plane as compared to {110} and {111} (cf. thecorresponding pole plot) planes. From Fig. 10(c) it may benoted that there is no specific texture observed in Ni3Bphase; however, the strength of orientation of grains isalso maximum along {100} plane as compared to {110} and{111} planes (cf. the corresponding pole plot). FromFig. 10(d) it may be noted that there is the presence oftexture in Ni phase; however, the strength of orientationof grains is also maximum along {100} and {111} planes ascompared to {110} plane.

3.2 Mechanical Properties of HVOF-SprayedNiCrBSi Coating

A detailed evaluation of microhardness in the coatedregion (on the top surface and along the cross-sectionalplane) was undertaken to understand the effect of laser

surface melting followed by HVOF spray deposition onthe microhardness of the top surface and its distribution.Figure 11 shows the microhardness profile with the depthfrom the surface of the coating developed by HVOFspraying (plot 1), and the same followed by laser surfacemelting on AISI 304 stainless steel (plot 2). From Fig. 11 itmay be noted that the average microhardness of thecoating in the as-coated and as-melted conditions is im-proved to 900 VHN and 1200 VHN, respectively, ascompared to the as-received substrate (250 VHN). Thesignificant increase in microhardness of the coating isattributed to the presence of nano-structured borides (ofCr2B and Ni3B) in grain refined and partially amorphousc-Ni matrix. The marginal variation of microhardness withdepth is attributed to the presence of composite structure.An increased hardness due to laser surface melting isattributed to refinement of microstructures and the pre-sence of silicides in the matrix along with borides.

4. Summary and Conclusions

In the present study, attempts have been made todevelop hard and wear resistant nano-borides (of chro-mium, Cr2B; and nickel, Ni3B)-dispersed composite coating(in c-Ni matrix) on AISI 304 stainless steel by laser-assisted HVOF spray deposition technique and has beencompared with the same deposited by HVOF spraying.From the detailed analysis the following conclusions maybe drawn:

1. Under optimum processing condition, HVOF spray-ing forms an adherent and continuous coating with thepresence of uniformly dispersed nano-borides (Cr2Band Ni3B) in metastable and partially amorphous c-Nimatrix.

2. Due to laser surface melting, there is an increasedrefinement of microstructures with formation of nano-borides of nickel and chromium (Ni3B, Cr2B, andCr2B3) and nano-silicides of nickel (Ni2Si), which arealso confirmed by transmission electron microscopicinvestigation.

3. A detailed microtexture analysis shows the presenceof no specific texture in Cr2B phase; however, thestrength of orientation of grains is maximum along{100} plane in comparison to {110} and {111} planes.Similarly, there is no specific texture observed in Ni3Bphase; however, the strength of orientation of grains ismaximum along {100} plane as compared to {110} and{111} planes. Due to the absence of significantlycrystallinity no distinct orientation could be obtainedfor c-Ni phase.

4. The average microhardness was improved to 750-900VHN as compared to 250 VHN of the as-receivedsubstrate. Laser surface melting improves the microh-ardness further to as high as 1400 VHN due to refine-ment of microstructure further and the presence ofsilicides.

Fig. 11 Microhardness profiles with the depth from the surfaceof the coating developed by HVOF spraying (plot 1) and thesame followed by laser surface melting (plot 2) on AISI 304stainless steel substrate

Journal of Thermal Spray Technology

Peer

Revie

wed

Acknowledgment

Partial financial supports from the Council of Scientificand Industrial Research (CSIR), N. Delhi; Department ofScience and Technology (DST), N. Delhi; and KalpanaChawla Space Technology Centre, IIT Kharagpur aregratefully acknowledged.

References:

1. J. Dutta Majumdar and I. Manna, Ed., Introduction to Laser-Assisted Fabrication of Materials, Laser-Assisted Fabrication ofMaterials, Springer Series in Materials Science, vol. 161, Springer,Berlin, 2013, p 1-67. DOI:10.1007/978-3-642-28359-8_1

2. Suleiman.M. Elhamali, K.M. Etmimi, and A. Usha, The Effect ofLaser Surface Melting on the Microstructure and MechanicalProperties of low Carbon Steel, World Acad. Sci. Eng. Technol.,2013, 75, p 3-20

3. S. Kuroda, J. Kawakita, M. Watanabe, and H. Katanoda, WarmSpraying—A Novel Coating Process Based on High-VelocityImpact of Solid Particles, Sci. Technol. Adv. Mater., 2008, 9, p 17

4. Y. Ishikawa, J. Kawakita, S. Osawa, T. Itsukaichi, Y. Sakamoto,M. Takaya, and S. Kuroda, Evaluation of Corrosion and WearResistance of Hard Cermet Coatings Sprayed by Using an Im-proved HVOF Process, J. Therm. Spray Technol., 2005, 14(3), p384-390

5. K. Raghu Ram Mohan Reddy, M.M.M. Sarcar, and N. Raman-aiah, Tribological Behavior of WC-Co/NiCrAlY Coatings on Ti-6Al-4V, Int. J. Adv. Sci. Technol., 2013, 57, p 37-44

6. P. Sharma and J. Dutta Majumdar, Microstructural Character-ization and Properties Evaluation of Ni-Based Hardfaced Coat-ing on AISI, 304 Stainless Steel by High Velocity OxyfuelCoating Technique, Metall. Mater. Trans. A, 2012, 44A, p 372-380

7. J.M. Miguel, J.M. Guilemany, and S. Vizcaino, Tribological Studyof NiCrBSi Coating Obtained by Different Processes, Tribol. Int.,2003, 36, p 181-187

8. I. Hemmati, V. Ocelı́k, and J.Th.M. De Hosson, Effects of the AlloyComposition on Phase Constitution and Properties of LaserDeposited Ni-Cr-B-Si Coatings, Phys. Procedia, 2013, p 302-311

9. M. Zhong, W. Liu, and H. Zhang, Corrosion and Wear Resis-tance Characteristics of NiCr Coating by Laser Alloying withPowder Feeding on Grey Iron Liner, Wear, 2006, 260, p 1349-1355

10. C. Tassin, F. Laroudie, M. Pons, and L. Lelait, Improvement ofthe Wear Resistance of 316L Stainless Steel by Laser SurfaceAlloying, Surf. Coat. Technol., 1996, 80, p 207-210

11. J. Dutta Majumdar, B. Ramesh Chandra, and I. Manna, LaserComposite Surfacing of AISI 304 Stainless Steel with TitaniumBoride for Improved Wear Resistance, Tribol. Int., 2007, 40, p146-152

12. A. Cockburn, M. Bray, and W. O�Neill, The Laser Assisted ColdSpray Process, Laser User, 2008, 53, p 30-31

13. B. D. Cullity, Addison-Wesley Publishing Company Inc., Philip-pines, Elements of X-ray Diffraction, 1967

14. T. Kanichi and K. Hidaka, Hard Facing Nickel-Base Alloy, U.S.Patent 4,404,049, U.S. Patent and Trademark Office, Alexandria,VA, 1984

15. I. Hemmati, V. Ocelı́k, and J.Th.M. De Hosson, Effects of theAlloy Composition on Phase Constitution and Properties of La-ser Deposited Ni-Cr-B-Si Coatings, Phys. Procedia, 2013, 41, p302-311

Journal of Thermal Spray Technology

Peer

Revie

wed