Properties of HVOF-PVD Duplex Coatings: History
Please note this is an old version of this entry, which may differ significantly from the current revision.

The morphology (surface and cross-section) of the high-velocity oxygen–fuel coupled physical vapor deposition (HVOF-PVD)  duplex coating and its mechanical (stress and load-bearing capacity), tribological (wear and lubrication), and corrosion (chemical and electrochemical) behavior are described and discussed for surface protective concern. The duplex coating involves a combination of a thick, hard HVOF bottom layer and a thin, hard yet tough PVD top layer. The hardness and modulus of the HVOF coating are between those of the soft substrate and the hard PVD coating, which thereafter provides a smooth transition and effective support between them. As a result, the HVOF interlayer can eliminate the plastic deformation of the substrate due to stress concentration under heavy load, effectively avoiding the “eggshell effect”. As expected, the duplex coating system would provide excellent load-bearing capacity. In terms of tribology, the wear resistance of the HVOF-PVD duplex coating is significantly improved compared to that of PVD monolayer coating. 

  • thermal spray
  • HVOF
  • PVD
  • microstructure
  • mechanical properties

1. Introduction

Thermal spraying is a general term for a series of coating processes. The process involves the powder material being given thermal and kinetic energy in a hot air flow medium and sprayed onto the substrate at high speed to form a coating [1][2][3][4]. Over the past few decades, a series of thermal spray technologies have been developed, such as electric arc spraying (EAS), plasma spraying (PS), detonation spraying (DS), and high-speed oxy-fuel (HVOF) spraying [5][6][7][8][9]. In particular, HVOF spraying achieves a favorable combination of thermal and kinetic energy due to its high speed (~1500 m/s) and relatively low temperature (~2000 °C) [10]. In addition, it benefits the advantage of high flexibility (such as the deposition of cermets, oxide and oxide-free ceramics coatings) and low cost for mass production [11][12]. Thus, HVOF coating as a protective candidate has been widely used in various industrial fields, such as aviation, aerospace, petroleum, and marine components as well as systems [13][14][15]. It can be observed that the raw material powder and the spraying process are two key factors for the coatings prepared by HVOF spraying. Therefore, designing and optimizing the raw material powder and spraying process parameters is quite crucial before coating deposition. Typically, the powder material consists of a metal/ceramic primary phase and metal binder phase (Co, Cr, Ni, etc.) with a particle size distribution of 10–40 μm [16][17][18]. At present, a variety of commercial feedstock powders have been developed, mainly including but not limited to WC-based, Cr3C2-based, and Fe-based powders [19][20][21]. Moreover, many researchers have conducted structural and compositional modifications based on commercial feedstock powders to obtain high-quality HVOF spray coatings [22][23][24]. In addition, the HVOF spraying parameters particularly involving the feature and flow rate of working gas and the ratio of oxygen/fuel gas make a great contribution to the temperature, airflow velocity and decomposed composition during deposition, which could change the structure and properties of coatings, such as strength, toughness and residual stresses, to a great extent [10][25]. As a result, it is empirically known that the performance of HVOF spray coating shows strong dependence upon the combined effect of feedstock powder materials and the spraying processes.

2. Mechanical Properties

It can be understood that the HVOF interlayer provides effective support for the PVD top layer. In addition, the scratch test results also show that the HVOF interlayer can significantly improve the interfacial bond strength of the PVD coating. In conclusion, the dual-phase coating design greatly eliminates the stress concentration at the interface between the PVD coating and the soft substrate, effectively inhibiting the plastic deformation of the substrate under heavy load, thereby significantly improving the load-bearing capacity of the PVD coating [28]. Incidentally, once the thickness of the HVOF interlayer covers the stress concentration region, its thickness value has little effect on the load-bearing capacity of the PVD coating. This point can be concluded from the simulation and experimental results of Zheng and Li et al. [26][29].

3. Tribological Performance

While under the same test parameters, the PVD coating in the HVOF-PVD duplex coating was not severely delaminated, which only showed deep furrows and small separations under shear action. It is not difficult to find that the wear resistance of the duplex coating has made a qualitative leap after introducing the HVOF interlayer between the soft substrate and the PVD coating. It can be attributed to the successful transfer of surface contact stresses and improved adhesion in the duplex coating system [36]. It should be further pointed out that the hardness and thickness of the HVOF interlayer will also affect the wear resistance of the duplex coating to a certain extent [26][37]. However, the impact of these factors appears to be negligible.

4. Corrosion Behavior

In addition to electrochemical corrosion, chemical corrosion is also another common corrosion phenomenon that produces loss and damage to materials [47][48]. Tang et al. [39] studied the hot corrosion behavior of HVOF (Cr3C2-NiCr) coatings and HVOF-PVD (Cr3C2-NiCr/CrN) duplex coatings in mixed salts at 550 °C.

This entry is adapted from the peer-reviewed paper 10.3390/coatings12101395

References

  1. Tan, J.; Looney, L.; Hashmi, M. Component repair using HVOF thermal spraying. J. Mater. Process. Technol. 1999, 92, 203–208.
  2. Zhang, H.; Wang, X.Y.; Zheng, L.L. Studies of splat morphology and rapid solidification during thermal spraying. Int. J. Heat Mass Transf. 2001, 44, 4579–4592.
  3. Yang, K.; Min, L.; Zhou, K.; Deng, C. Recent Developments in the Research of Splat Formation Process in Thermal Spraying. J. Mater. 2012, 2013, 1–14.
  4. Paredes, R.; Amico, S.; d’Oliveira, A. The effect of roughness and pre-heating of the substrate on the morphology of aluminum coatings deposited by thermal spraying. Surf. Coat. Technol. 2006, 200, 3049–3055.
  5. Niranatlumpong, P.; Koiprasert, H. Phase transformation of NiCrBSi–WC and NiBSi–WC arc sprayed coatings. Surf. Coat. Technol. 2011, 206, 440–445.
  6. Pfender, E. Fundamental studies associated with the plasma spray process. Surf. Coat. Technol. 1988, 34, 1–14.
  7. Wang, J.; Zhang, L.; Sun, B.; Zhou, Y. Study of the Cr3C2–NiCr detonation spray coating. Surf. Coat. Technol. 2000, 130, 69–73.
  8. Stewart, D.; Shipway, P.; McCartney, D. Abrasive wear behavior of conventional and nanocomposite HVOF-sprayed WC–Co coatings. Wear 1999, 225, 789–798.
  9. Wang, Q.; Chen, Z.; Ding, Z. Performance of abrasive wear of WC-12Co coatings sprayed by HVOF. Tribol. Int. 2009, 42, 1046–1051.
  10. Yu, J.; Liu, X.; Yu, Y.; Li, H.; Liu, P.; Huang, K.; Sun, R. Research and Application of High-Velocity Oxygen Fuel Coatings. Coatings 2022, 12, 828.
  11. Brezinova, J.; Guzanová, A.; Draganovska, D.; Maruschak, P.O.; Landová, M. Study of selected proper-ties of thermally sprayed coatings containing WC and WB hard particles. Acta Mech. Autom. 2016, 10, 296–299.
  12. Brezinova, J.; Guzanová, A.; Tkáčová, J.; Brezina, J.; L’achova, K.; Draganovska, D.; Pastorek, F.; Maruschak, P.; Prentkovskis, O. High velocity oxygen liquid-fuel (HVOLF) spraying of WC-based coatings for transport industrial applications. Metals 2020, 10, 1675.
  13. Wang, Q.; Zhang, S.; Cheng, Y.; Xiang, J.; Zhao, X.; Yang, G. Wear and corrosion performance of WC-10Co4Cr coatings deposited by different HVOF and HVAF spraying processes. Surf. Coat. Technol. 2013, 218, 127–136.
  14. Picas, J.; Forn, A.; Matthäus, G. HVOF coatings as an alternative to hard chrome for pistons and valves. Wear 2006, 261, 477–484.
  15. Wielage, B.; Wank, A.; Pokhmurska, H.; Grund, T.; Rupprecht, C.; Reisel, G.; Friesen, E. Development and trends in HVOF spraying technology. Surf. Coat. Technol. 2006, 201, 2032–2037.
  16. Picas, J.; Punset, M.; Baile, M.T.; Martín, E.; Forn, A. Effect of oxygen/fuel ratio on the in-flight particle parameters and properties of HVOF WC-CoCr coatings. Surf. Coat. Technol. 2011, 205, S364–S368.
  17. Roy, M.; Pauschitz, A.; Bernardi, J.; Koch, T.; Franek, F. Microstructure and mechanical properties of HVOF sprayed nanocrystalline Cr3C2-25 (Ni20Cr) coating. J. Therm. Spray Technol. 2006, 15, 372–381.
  18. Zhang, C.; Liu, L.; Chan, K.C.; Chen, Q.; Tang, C.Y. Wear behavior of HVOF-sprayed Fe-based amorphous coatings. Intermetallics 2012, 29, 80–85.
  19. Lovelock, H.L.D.V. Powder/processing/structure relationships in WC-Co thermal spray coatings: A review of the published literature. J. Therm. Spray Technol. 1998, 7, 357–373.
  20. Guilemany, J.M.; Fernández, J.; Delgado, J.; Benedetti, A.V.; Clement, F. Effects of thickness coating on the electrochemical behavior of thermal spray Cr3C2–NiCr coatings. Surf. Coat. Technol. 2002, 153, 107–113.
  21. Huang, B.; Zhang, C.; Zhang, G.; Liao, H. Wear and corrosion resistant performance of thermal-sprayed Fe-based amorphous coatings: A review. Surf. Coat. Technol. 2019, 377, 124896.
  22. Poblano-Salas, C.; Cabral-Miramontes, J.; Gallegos-Melgar, A.; Ruiz-Luna, H.; Aguilar-Escobar, J.; Espinosa-Arbelaez, D.; Espinoza-Beltrán, F.; Trapaga-Martínez, G.; Muñoz-Saldaña, J. Effects of VC additions on the mechanical properties of bimodal WC–Co HVOF thermal sprayed coatings measured by nanoindentation. Int. J. Refract. Met. Hard Mater. 2015, 48, 167–178.
  23. Yin, B.; Liu, G.; Zhou, H.; Chen, J.; Yan, F. Sliding wear behavior of HVOF-sprayed Cr3C2–NiCr/CeO2 composite coatings at elevated temperature up to 800 °C. Tribol. Lett. 2010, 37, 463–475.
  24. Wang, Q.; Zhang, Y.; Ding, X.; Wang, S.; Ramachandran, C.S. Effect of WC grain size and abrasive type on the wear performance of HVOF-sprayed WC-20Cr3C2-7Ni coatings. Coatings 2020, 10, 660.
  25. Li, M.; Christofides, P.D. Modeling, and control of high-velocity oxygen-fuel (HVOF) thermal spray: A tutorial review. J. Therm. Spray Technol. 2009, 18, 753–768.
  26. Li, W.; Zhao, Y.; He, D.; Song, Q.; Sun, X.; Wang, S.; Zhai, H.; Zheng, W.; Wood, R.J. Optimizing mechanical and tribological properties of DLC/Cr3C2-NiCr duplex coating via tailoring interlayer thickness. Surf. Coat. Technol. 2022, 434, 128198.
  27. Wänstrand, O.; Larsson, M.; Kassman-Rudolphi, Å. An experimental method for evaluation of the load-carrying capacity of coated aluminum: The influence of coating stiffness, hardness, and thickness. Surf. Coat. Technol. 2000, 127, 107–113.
  28. Chen, W.; Mao, T.; Zhang, B.; Zhang, S.; Meng, X. Designs and preparation of advanced HVOF-PVD duplex coating by a combination of HVOF and arc ion plating. Surf. Coat. Technol. 2016, 304, 125–133.
  29. Zheng, W.; He, D.; Li, W.; Shang, L.; Song, Q.; Zhang, G.; Zhai, H.; Cheng, B. AlCrN/Cr3C2–NiCr duplex coating towards high load-bearing and dry sliding antiwear applications. Ceram. Int. 2022, 48, 18933–18943.
  30. Hogmark, S.; Jacobson, S.; Larsson, M. Design, and evaluation of tribological coatings. Wear 2000, 246, 20–33.
  31. Donnet, C.; Erdemir, A. Historical developments and new trends in tribological and solid lubricant coatings. Surf. Coat. Technol. 2004, 180, 76–84.
  32. Voevodin, A.A.; O’Neill, J.P.; Zabinski, J.S. Nanocomposite tribological coatings for aerospace applications. Surf. Coat. Technol. 1999, 116–119, 36–45.
  33. Li, W.; Tang, P.; Shang, L.; He, D.; Wang, L.; Zhang, G.; Jin, K. Tribological behaviors of CrN/Cr3C2-NiCr duplex coating at elevated temperatures. Surf. Coat. Technol. 2019, 378, 124926.
  34. Shang, L.; Li, W.; He, D.; Tang, P.; Zhang, G.; Lu, Z. Mechanical and high-temperature tribological properties of Cr3C2-NiCr/TiN duplex coating. J. Mater. Eng. Perform. 2020, 29, 7207–7220.
  35. Panjan, P.; Drnovšek, A.; Gelman, P.; Čekada, M.; Panjan, M. Review of growth defects in thin films prepared by PVD techniques. Coatings 2020, 10, 447.
  36. Bemporad, E.; Sebastiani, M.; Casadei, F.; Carassiti, F. Modelling, product, action, and characterization of duplex coatings (HVOF and PVD) on Ti–6Al–4V substrate for specific mechanical applications. Surf. Coat. Technol. 2007, 201, 7652–7662.
  37. Pougoum, F.; Qian, J.; Laberge, M.; Martinu, L.; Klemberg-Sapieha, J.; Zhou, Z.; Li, K.Y.; Savoie, S.; Schulz, R. Investigation of Fe3Al-based PVD/HVOF duplex coatings to protect stainless steel from sliding wear against alumina. Surf. Coat. Technol. 2018, 350, 699–711.
  38. Pougoum, F.; Qian, J.; Martinu, L.; Klemberg-Sapieha, J.; Zhou, Z.; Li, K.Y.; Savoie, S.; Lacasse, R.; Potvin, E.; Schulz, R. Study of corrosion and tribocorrosion of Fe3Al-based duplex PVD/HVOF coatings against alumina in NaCl solution. Surf. Coat. Technol. 2019, 357, 774–783.
  39. Tang, P.; He, D.; Li, W.; Shang, L.; Zhang, G. Achieving superior hot corrosion resistance by PVD/HVOF duplex design. Corros. Sci. 2020, 175, 108845.
  40. Monticelli, C.; Balbo, A.; Zucchi, F. Corrosion and tribocorrosion behavior of cermet and cermet/nanoscale multilayer CrN/NbN coatings. Surf. Coat. Technol. 2010, 204, 1452–1460.
  41. Li, Y.; Qu, L.; Wang, F. The electrochemical corrosion behavior of TiN and (Ti, Al)N coatings in acid and salt solution. Corros. Sci. 2003, 45, 1367–1381.
  42. Duan, H.; Du, K.; Yan, C.; Wang, F. Electrochemical corrosion behavior of composite coatings of sealed MAO film on magnesium alloy AZ91D. Electrochim. Acta 2006, 51, 2898–2908.
  43. Zhang, Y.; Wang, Q.; Chen, G.; Ramachandran, C.S. Mechanical, tribological, and corrosion physiognomies of CNT-Al metal matrix composite (MMC) coatings deposited by cold gas dynamic spray (CGDS) process. Surf. Coat. Technol. 2020, 403, 126380.
  44. Mda, B.; Munk, C.; Ys, C.; Cmk, A.; Akk, D.; Pk, B.; Mm, B.; Pm, D.; Park, B.; Rkg, C. Modification of surface hardness, wear resistance and corrosion resistance of cold spray Al coated AZ31B Mg alloy using cold spray double layered Ta/Ti coating in 3.5wt%NaCl solution. Corros. Sci. 2020, 176, 109029.
  45. Gong, Y.; Geng, J.; Huang, J.; Chen, Z.; Wang, H. Self-healing performance and corrosion resistance of novel CeO2-sealed MAO film on aluminum alloy. Surf. Coat. Technol. 2021, 417, 127208.
  46. Zhao, Y.; Xu, F.; Zhang, D.; Xu, J.; Shi, X.; Sun, S.; Zhao, W.; Gao, C.; Zuo, D. Enhanced tribological and corrosion properties of DLC/CrN multilayer films deposited by HPPMS. Ceram. Int. 2022, 48, 25569–25577.
  47. Santosh, K.; Manoj, K.; Amit, H. Combating hot corrosion of boiler tubes—A study. Eng. Fail. Anal. 2018, 94, 379–395.
  48. Wang, Z.; Ma, G.; Li, Z.; Ruan, H.; Yuan, J.; Wang, L.; Ke, P.; Wang, A. Corrosion mechanism of Ti2AlC MAX phase coatings under the synergistic effects of water vapor and solid NaCl at 600 °C. Corros. Sci. 2021, 192, 109788.
  49. Wang, J.; Li, D.; Shao, T. Hot corrosion and electrochemical behavior of NiCrAlY, NiCoCrAlY and NiCoCrAlYTa coatings in molten NaCl-Na2SO4 at 800 °C. Surf. Coat. Technol. 2022, 440, 128503.
  50. Verdian, M.M.; Raeissi, K.; Salehi, M. The Corrosion performance of HVOF and APS thermally sprayed NiTi intermetallic coatings in 3.5% NaCl solution. Corros. Sci. 2010, 52, 1052–1059.
  51. Liu, C.; Bi, Q.; Matthews, A. EIS comparison on corrosion performance of PVD TiN and CrN coated mild steel in 0.5 N NaCl aqueous solution. Corros. Sci. 2001, 43, 1953–1961.
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