Fabrication of vacuum-arc Ti-Al-N coatings using multicomponent SHS-compacted cathodes
The results of experiments on the deposition of vacuum-arc Ti-Al-N coatings using aluminum-containing pressed cathodes based on nonstoichiometric titanium carbide TC0.5 are presented. The composition and morphology of coatings are investigated using electron probe microanalysis and scanning electron microscopy. Hardness and elasticity modulus were determined using the nanoindentation method. It is established that carbon is absent in the coating, while the fraction of aluminum in it decreases compared with its content in the cathode material. A superhard coating with nanohardness H = 59 GPa and the Young modulus E = 475 GPa is obtained from the cathode with the calculated composition TiC0.5-30%Al. By the ratio of hardness to the elasticity modulus, which equals H/E = 0.124, this coating is an amorphous-crystalline material. When using cathodes based on refractory nonstoichiometric titanium carbide, the content of the drop phase in coatings substantially lowers with no separation of the plasma flow. In general, the application of multicomponent SHS-compacted cathodes based on nonstoichiometric titanium carbide TiC0.5 makes it possible to fabricate superhard nanocrystalline coatings according to the standard technology using a serial vacuum-arc installation.