Microstructure and Wear Resistance of Plasma-sprayed and Detonation-sprayed (TiCrC)Ni Composite Coatings
摘要
The microstructure and wear resistance of thermal spray composite coatings produced from nickel-clad titanium–chromium carbide ((TiCrC)–33 wt.% Ni) by plasma and detonation spraying were examined. The microstructure of the plasma-sprayed and detonation-sprayed coatings was multiphase and consisted of a nickel-based metal matrix with uniformly distributed grains of complex titanium and chromium carbides. The microhardness of the dark gray carbide phase was 24 GPa in the plasma-sprayed coatings and 21.6 GPa in the detonation-sprayed coatings. To evaluate wear resistance, flat samples with plasma-sprayed and detonation-sprayed (TiCrC)Ni composite coatings were produced. For comparison, reference samples were prepared from the industrial KKhN-35 material (65 wt.% Cr3C2–35 wt.% NiCr) and from ShKh15 steel (equivalents: G52986 in the USA, 1.3505 in the EU, and 100Cr6 in France) with 58–63 HRC hardness. To evaluate wear rate, a method for rapid testing of coatings by dry friction using the ASK-01 system was developed and tested. The friction test unit simulated sliding friction of a ShKh15 steel counterface against a fixed flat sample with a thermal spray coating. The wear of the tested samples was measured, and the results were computer processed and interpreted. All coating samples showed greater wear resistance than the ShKh15 steel sample. The linear wear of the coatings was 3.7–4.1 times less than that of the steel sample. The plasma-sprayed and detonation-sprayed (TiCrC)Ni coatings had greater wear resistance than the plasma-sprayed coating made of the industrial KKhN-35 material. The detonation-sprayed coating from the (TiCrC)–33 wt.% Ni composite of PKKhT-33 grade exhibited the best wear resistance under dry sliding friction against ShKh15 steel. Its linear wear was approximately 1.3 times less than that of the plasma-sprayed KKhN-35 and PKKhT-33 coatings, while its weight loss was approximately 3–5 times less.