INVESTIGATION OF MULTILAYER SUPERHARD Ti-Hf-Si-N/NbN/Al_2O_3 COATINGS FOR HIGH PERFORMANCE PROTECTION

摘要

In this work we first obtained multilayered solid micro-and nanostructured coatings produced by several deposition techniques based on Ti-Hf-Si-N/NbN/Al_2O_3 on the steel substrate. It was found that the investigated coatings, along with high hardness (H) from 47 to 56 GPa and modulus of elasticity (E) from 435 to 570 GPa, the plasticity index We = (0.08-0.11), have a fairly low coefficient of friction (μ) which varies from 0.02 to 0.001 for a given mode of deposition. It is also shown that these multilayered coatings have high thermal stability (above 1000C). The annealing temperature up to 1070°C in a vacuum about 10~(-2) Pa showed that the coating in the upper layers consisting of Ti-Hf-Si-N/NbN the size of nanograins increases from 25 to 56 nm (for the Ti-Hf-Si-N) and from 14-15 to 35-37 nm for NbN. The increase of steel microhardness at the "coating - substrate" interface, is due to the presence of the hardening near the border with coating formed as a result of impact during abrasive blasting and deposition of coating.