Thermal stability of Ti-Si-N super hard nanocomposite coatings

Ti-Si-N coatings were deposited on HSS (high speed steel) substrates by pulsed D.C. PCVD with an self-made industrial equipment. Investigations on the microstructure and microhardness of these coatings at both normal temperatures and elevated temperatures were performed. The present study was emphasis on the thermal stability of Ti-Si-N super hard nano composite coatings with different Si contents, including the dependence of Si contents and the annealing temperatures, the microstructure, the crystallite size and microhardness of Ti-Si-N coatings. The results indicate that the coatings show a superiority of the thermal stability, the micro-hardness and the crystallite size even at 900 degrees C. It may be due to the coating still disassembles following the rule of amplitude modulation disassembly theory.