Journal of Thermal Spray Technology

, Volume 28, Issue 1–2, pp 174–188 | Cite as

Influence of Powder Microstructure on the Microstructural Evolution of As-Sprayed and Heat Treated Cold-Sprayed Ti-6Al-4V Coatings

  • Venkata Satish Bhattiprolu
  • Kyle W. Johnson
  • Grant A. CrawfordEmail author
Peer Reviewed


Cold spray repair of high-value titanium alloy components has gained considerable interest; however, the influence of deposition conditions on the resulting microstructure and properties is not well established. This work examines the influence of feedstock powder type on the microstructural evolution of cold spray-deposited Ti-6Al-4V powders following deposition and after low-temperature heat treatment. Plasma-atomized, gas-atomized, and hydride de-hydride Ti-6Al-4V powders were deposited on Ti-6Al-4V substrates using cold spray technology and subsequently annealed at 550 °C for 5 h. Powders and cold spray depositions were characterized using x-ray diffraction, optical microscopy, scanning electron microscopy, and electron backscatter diffraction. Atomized and hydride de-hydride powders were characterized by a martensitic alpha and equiaxed alpha microstructure, respectively. Phase analysis revealed hydride de-hydride powders to contain beta phase regions near alpha grain boundaries; however, beta phase was not observed in atomized powders. Atomized coatings retained their powder microstructure in particle interiors but demonstrated ultra-fine grain formation near particle boundaries, likely due to dynamic recrystallization. In contrast, hydride de-hydride powders showed a larger increase in microstrain after deposition, without ultra-fine grain formation. Heat treatment resulted in recovery and recrystallization for all coatings and, in the case of atomized coatings, resulted in beta phase precipitation in regions that experienced large plastic strains.


annealing cold gas dynamic spraying Ti-6Al-4V precipitation EBSD 



The authors are thankful for the financial support of U.S. Army Research, Development and Engineering Command under Contract No. WI5QKN-16-C-0094.

Compliance with Ethical Standards

Conflict of interest

The authors have no conflicts of interest to disclose.


  1. 1.
    B. Dutta and F.S. Froes, The Additive Manufacturing (AM) of Titanium Alloys, Met. Powder Rep., 2017, 7(2), p 96-106CrossRefGoogle Scholar
  2. 2.
    C. Widener, M. Carter, O. Ozdemir, R. Hrabe, B. Hoiland, T. Stamey, V. Champagne, and T. Eden, Application of High-Pressure Cold Spray for an Internal Bore Repair of a Navy Valve Actuator, J. Therm. Spray Technol., 2016, 25(1-2), p 193-201CrossRefGoogle Scholar
  3. 3.
    R. Jones, N. Matthews, C. Rodopoulos, K. Cairns, and S. Pitt, On the Use of Supersonic Particle Deposition to Restore the Structural Integrity of Damaged Aircraft Structures, Int. J. Fatigue, 2011, 33(9), p 1257-1267CrossRefGoogle Scholar
  4. 4.
    V. Champagne and D. Helfritch, Critical Assessment 11: Structural Repairs by Cold Spray, Mater. Sci. Technol., 2015, 31(6), p 627-634CrossRefGoogle Scholar
  5. 5.
    D. Goldbaum, R.R. Chromik, N. Brodusch, and R. Gauvin, Microstructure and Mechanical Properties of Ti Cold-Spray Splats Determined by Electron Channeling Contrast Imaging and Nanoindentation Mapping, Microsc. Microanal., 2015, 21(3), p 570-581CrossRefGoogle Scholar
  6. 6.
    D. Goldbaum, R.R. Chromik, S. Yue, E. Irissou, and J.-G. Legoux, Mechanical Property Mapping of Cold Sprayed Ti Splats and Coatings, J. Therm. Spray Technol., 2011, 20(3), p 486-496CrossRefGoogle Scholar
  7. 7.
    D. Goldbaum, J.M. Shockley, R.R. Chromik, A. Rezaeian, S. Yue, J.-G. Legoux, and E. Irissou, The Effect of Deposition Conditions on Adhesion Strength of Ti and Ti6Al4V Cold Spray Splats, J. Therm. Spray Technol., 2012, 21(2), p 288-303CrossRefGoogle Scholar
  8. 8.
    M.V. Vidaller, A. List, F. Gaertner, T. Klassen, S. Dosta, and J.M. Guilemany, Single Impact Bonding of Cold Sprayed Ti-6Al-4V Powders on Different Substrates, J. Therm. Spray Technol., 2015, 24(4), p 644-658CrossRefGoogle Scholar
  9. 9.
    W.Y. Li, C. Zhang, X. Guo, J. Xu, C.J. Li, H. Liao, C. Coddet, and K.A. Khor, Ti and Ti-6Al-4V Coatings by Cold Spraying and Microstructure Modification by Heat Treatment, Adv. Eng. Mater., 2007, 9(5), p 418-423CrossRefGoogle Scholar
  10. 10.
    P. Vo, E. Irissou, J.-G. Legoux, and S. Yue, Mechanical and Microstructural Characterization of Cold-Sprayed Ti-6Al-4V After Heat Treatment, J. Therm. Spray Technol., 2013, 22(6), p 954-964CrossRefGoogle Scholar
  11. 11.
    V.S. Bhattiprolu, K.W. Johnson, O.C. Ozdemir, and G.A. Crawford, Influence of Feedstock Powder and Cold Spray Processing Parameters on Microstructure and Mechanical Properties of Ti-6Al-4V Cold Spray Depositions, Surf. Coat. Technol., 2018, 335, p 1-12CrossRefGoogle Scholar
  12. 12.
    G. Bae, S. Kumar, S. Yoon, K. Kang, H. Na, H.-J. Kim, and C. Lee, Bonding Features and Associated Mechanisms in Kinetic Sprayed Titanium Coatings, Acta Mater., 2009, 57(19), p 5654-5666CrossRefGoogle Scholar
  13. 13.
    V.N.V. Munagala, V. Akinyi, P. Vo, and R.R. Chromik, Influence of Powder Morphology and Microstructure on the Cold Spray and Mechanical Properties of Ti6Al4V Coatings, J. Therm. Spray Technol., 2018, 27(5), p 827-842CrossRefGoogle Scholar
  14. 14.
    K. Binder, J. Gottschalk, M. Kollenda, F. Gärtner, and T. Klassen, Influence of Impact Angle and Gas Temperature on Mechanical Properties of Titanium Cold Spray Deposits, J. Therm. Spray Technol., 2011, 20(1-2), p 234-242CrossRefGoogle Scholar
  15. 15.
    S.H. Zahiri, W. Yang, and M. Jahedi, Characterization of Cold Spray Titanium Supersonic Jet, J. Therm. Spray Technol., 2009, 18(1), p 110-117CrossRefGoogle Scholar
  16. 16.
    N. Khun, A. Tan, W. Sun, and E. Liu, Effect of Heat Treatment Temperature on Microstructure and Mechanical and Tribological Properties of Cold Sprayed Ti-6Al-4V Coatings, Tribol. Trans., 2017, 60(6), p 1033-1042CrossRefGoogle Scholar
  17. 17.
    A. Birt, V. Champagne, R. Sisson, and D. Apelian, Microstructural Analysis of Cold-Sprayed Ti-6Al-4V at the Micro-and Nano-Scale, J. Therm. Spray Technol., 2015, 24(7), p 1277-1288CrossRefGoogle Scholar
  18. 18.
    A. Birt, V. Champagne, R. Sisson, and D. Apelian, Microstructural Analysis of Ti-6Al-4V Powder for Cold Gas Dynamic Spray Applications, Adv. Powder Technol., 2015, 26(5), p 1335-1347CrossRefGoogle Scholar
  19. 19.
    J.Y. Lek, A. Bhowmik, A.W.-Y. Tan, W. Sun, X. Song, W. Zhai, P.J. Buenconsejo, F. Li, E. Liu, and Y.M. Lam, Understanding the Microstructural Evolution of Cold Sprayed Ti-6Al-4V Coatings on Ti-6Al-4V Substrates, Appl. Surf. Sci., 2018, 459, p 492-504CrossRefGoogle Scholar
  20. 20.
    A.W.-Y. Tan, W. Sun, A. Bhowmik, J.Y. Lek, I. Marinescu, F. Li, N.W. Khun, Z. Dong, and E. Liu, Effect of Coating Thickness on Microstructure, Mechanical Properties and Fracture Behaviour of Cold-Sprayed Ti6Al4V Coatings on Ti6Al4V Substrates, Surf. Coat. Technol., 2018, 349, p 303-317CrossRefGoogle Scholar
  21. 21.
    B. Vrancken, L. Thijs, J.-P. Kruth, and J. Van Humbeeck, Heat Treatment of Ti6Al4V Produced by Selective Laser Melting: Microstructure and Mechanical Properties, J. Alloy. Compd., 2012, 541, p 177-185CrossRefGoogle Scholar
  22. 22.
    M. Smagorinski and P. Tsantrizos, Production of Spherical Titanium Powder by Plasma Atomization, Adv. Powder. Metall. Part. Mater., 2002, 3, p 3-248Google Scholar
  23. 23.
    C. McCracken, D. Barbis, and R. Deeter, Key Characteristics of Hydride–Dehydride Titanium Powder, Powder Metall., 2011, 54(3), p 180-183CrossRefGoogle Scholar
  24. 24.
    A. Heidloff, J. Rieken, I. Anderson, D. Byrd, J. Sears, M. Glynn, and R. Ward, Advanced Gas Atomization Processing for Ti and Ti Alloy Powder Manufacturing, JOM, 2010, 62(5), p 35-41CrossRefGoogle Scholar
  25. 25.
    Y. Kim, E.-P. Kim, Y.-B. Song, S.H. Lee, and Y.-S. Kwon, Microstructure and Mechanical Properties of Hot Isostatically Pressed Ti-6Al-4V Alloy, J. Alloy. Compd., 2014, 603, p 207-212CrossRefGoogle Scholar
  26. 26.
    D.L. Olson, ASM Handbook: Welding, Brazing, and Soldering, ASM International, Geauga County, 1993CrossRefGoogle Scholar
  27. 27.
    H. Chandler, Heat Treater’s Guide: Practices and Procedures for Nonferrous Alloys, ASM International, Geauga County, 1996Google Scholar
  28. 28.
    B.D. Cullity and S.R. Stock, Elements of X-ray Diffraction, Pearson Education, London, 2014Google Scholar
  29. 29.
    A.K. Swarnakar, O. Van der Biest, and B. Baufeld, Thermal Expansion and Lattice Parameters of Shaped Metal Deposited Ti-6Al-4V, J. Alloy. Compd., 2011, 509(6), p 2723-2728CrossRefGoogle Scholar
  30. 30.
    D. Rafaja, T. Schucknecht, V. Klemm, A. Paul, and H. Berek, Microstructural Characterisation of Titanium Coatings Deposited Using Cold Gas Spraying on Al2O3 Substrates, Surf. Coat. Technol., 2009, 203(20), p 3206-3213CrossRefGoogle Scholar
  31. 31.
    A. Monshi, M.R. Foroughi, and M.R. Monshi, Modified Scherrer Equation to Estimate More Accurately Nano-crystallite Size Using XRD, World J. Nano Sci. Eng., 2012, 2(3), p 154-160CrossRefGoogle Scholar
  32. 32.
    B.D. Cullity and J.W. Weymouth, Elements of X-ray Diffraction, Am. J. Phys., 1957, 25(6), p 394-395CrossRefGoogle Scholar
  33. 33.
    T. Hussain, Cold Spraying of Titanium: A Review of Bonding Mechanisms, Microstructure and Properties, Key Engineering Materials, Trans Tech Publications, Zürich, 2013, p 53-90Google Scholar
  34. 34.
    C.K. Moy, J. Cairney, G. Ranzi, M. Jahedi, and S.P. Ringer, Investigating the Microstructure and Composition of Cold Gas-Dynamic Spray (CGDS) Ti Powder Deposited on Al 6063 Substrate, Surf. Coat. Technol., 2010, 204(23), p 3739-3749CrossRefGoogle Scholar
  35. 35.
    T. Ahmed and H. Rack, Phase Transformations During Cooling in α + β Titanium Alloys, Mater. Sci. Eng., A, 1998, 243(1), p 206-211CrossRefGoogle Scholar
  36. 36.
    D.C. Hurley, D. Balzar, P. Purtscher, and K. Hollman, Nonlinear Ultrasonic Parameter in Quenched Martensitic Steels, J. Appl. Phys., 1998, 83(9), p 4584-4588CrossRefGoogle Scholar
  37. 37.
    B.V. Vincente, D.R.N. Correa, T.A.G. Donato, V.E. Arana-Chavez, M.A.R. Buzalaf, and C.R. Grandini, The Influence of Small Quantities of Oxygen in the Structure, Microstructure, Hardness, Elasticity Modulus and Cytocompatibility of Ti-Zr Alloys for Dental Applications, Metals, 2014, 7(1), p 542-553Google Scholar
  38. 38.
    R. Montanari, G. Costanza, M. Tata, and C. Testani, Lattice Expansion of Ti-6Al-4V by Nitrogen and Oxygen Absorption, Mater. Charact., 2008, 59(3), p 334-337CrossRefGoogle Scholar
  39. 39.
    J.-M. Oh, B.-G. Lee, S.-W. Cho, S.-W. Lee, G.-S. Choi, and J.-W. Lim, Oxygen Effects on the Mechanical Properties and Lattice Strain of Ti and Ti-6Al-4V, Met. Mater. Int., 2011, 17(5), p 733-736CrossRefGoogle Scholar
  40. 40.
    G. Welsch, R. Boyer, and E. Collings, Materials Properties Handbook: Titanium Alloys, ASM International, Geauga County, 1993Google Scholar
  41. 41.
    C. Lee and J. Kim, Microstructure of Kinetic Spray Coatings: A Review, J. Therm. Spray Technol., 2015, 24(4), p 592-610CrossRefGoogle Scholar
  42. 42.
    M. Rokni, S. Nutt, C. Widener, V. Champagne, and R. Hrabe, Review of Relationship Between Particle Deformation, Coating Microstructure, and Properties in High-Pressure Cold Spray, J. Therm. Spray Technol., 2017, 26(6), p 1308-1355CrossRefGoogle Scholar
  43. 43.
    F.J. Humphreys and M. Hatherly, Recrystallization and Related Annealing Phenomena, Elsevier, Amsterdam, 2012Google Scholar
  44. 44.
    M.J. Donachie, Titanium: A Technical Guide, ASM International, Geauga County, 2000Google Scholar
  45. 45.
    J.R. Davis and A.S.F. Metals, ASM Handbook 2. Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM International, Geauga County, 1998Google Scholar
  46. 46.
    A.-M. Bandar, P. Vo, R. Mongrain, E. Irissou, and S. Yue, Effect of Heat Treatment on the Microstructure and Mechanical Properties of Stainless Steel 316L Coatings Produced by Cold Spray for Biomedical Applications, J. Therm. Spray Technol., 2014, 23(4), p 641-652CrossRefGoogle Scholar
  47. 47.
    M. Rokni, C. Widener, and G. Crawford, Microstructural Evolution of 7075 Al Gas Atomized Powder and High-Pressure Cold Sprayed Deposition, Surf. Coat. Technol., 2014, 251, p 254-263CrossRefGoogle Scholar
  48. 48.
    Y. Zou, W. Qin, E. Irissou, J.-G. Legoux, S. Yue, and J.A. Szpunar, Dynamic Recrystallization in the Particle/Particle Interfacial Region of Cold-Sprayed Nickel Coating: Electron Backscatter Diffraction Characterization, Scr. Mater., 2009, 61(9), p 899-902CrossRefGoogle Scholar
  49. 49.
    K. Kim, M. Watanabe, J. Kawakita, and S. Kuroda, Grain Refinement in a Single Titanium Powder Particle Impacted at High Velocity, Scr. Mater., 2008, 59(7), p 768-771CrossRefGoogle Scholar
  50. 50.
    R.E. Reed-Hill, R. Abbaschian, and R. Abbaschian, Physical Metallurgy Principles, Van Nostrand, New York, 1973Google Scholar
  51. 51.
    T. Sakai, A. Belyakov, R. Kaibyshev, H. Miura, and J.J. Jonas, Dynamic and Post-Dynamic Recrystallization Under Hot, Cold and Severe Plastic Deformation Conditions, Prog. Mater Sci., 2014, 60, p 130-207CrossRefGoogle Scholar
  52. 52.
    S. Mironov, Y. Zhang, Y. Sato, and H. Kokawa, Crystallography of Transformed β Microstructure in Friction Stir Welded Ti-6Al-4V Alloy, Scr. Mater., 2008, 59(5), p 511-514CrossRefGoogle Scholar
  53. 53.
    D. Banerjee and J. Williams, Perspectives on Titanium Science and Technology, Acta Mater., 2013, 61(3), p 844-879CrossRefGoogle Scholar
  54. 54.
    M. Simonelli, Microstructure Evolution and Mechanical Properties of Selective Laser Melted Ti-6Al-4V. Marco Simonelli, 2014Google Scholar
  55. 55.
    H. Beladi, Q. Chao, and G.S. Rohrer, Variant Selection and Intervariant Crystallographic Planes Distribution in Martensite in a Ti-6Al-4V Alloy, Acta Mater., 2014, 80, p 478-489CrossRefGoogle Scholar
  56. 56.
    S.H. Zahiri, D. Fraser, and M. Jahedi, Recrystallization of Cold Spray-Fabricated CP Titanium Structures, J. Therm. Spray Technol., 2009, 18(1), p 16-22CrossRefGoogle Scholar
  57. 57.
    W. Xu, M. Brandt, S. Sun, J. Elambasseril, Q. Liu, K. Latham, K. Xia, and M. Qian, Additive Manufacturing of Strong and Ductile Ti-6Al-4V by Selective Laser Melting via in Situ Martensite Decomposition, Acta Mater., 2015, 85, p 74-84CrossRefGoogle Scholar
  58. 58.
    C.M. Kay and J. Karthikeyan, High Pressure Cold Spray: Principles and Applications, ASM International, Materials Park, 2016Google Scholar

Copyright information

© ASM International 2018

Authors and Affiliations

  • Venkata Satish Bhattiprolu
    • 1
  • Kyle W. Johnson
    • 2
  • Grant A. Crawford
    • 1
    Email author
  1. 1.Department of Materials and Metallurgical EngineeringSouth Dakota School of Mines and TechnologyRapid CityUSA
  2. 2.VRC Metal SystemsRapid CityUSA

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