Thermal Explosion Reaction Induced Rapid Deposition of Metal Carbides on the Surface of Diamond Particles

A mixture of metal (Ti, Cr, or W) powders and diamond particles was subjected to vacuum-heat treatment. The high temperature generated by the thermal-explosion reaction of the Ni–Al compact promoted the rapid sublimation of the metal powders, forming a carbide coating. Results showed that these metal elements evaporated rapidly and were deposited onto the surface of the diamond particles after the thermal explosion. The difference carbide coating was formed onto the surface of diamond particles. The carbides that formed in the coating were nanoscale or sub-microscale. Finally, the formation mechanism of coatings was explained from the perspectives of reaction thermodynamics and saturated evaporation pressure.