Influence of bias potential on the tribological behavior and physical-mechanical properties of TiAlSiY-based nanostructured coatings

Nanostructured multicomponent (TiAlSiY)N coatings were fabricated by the vacuum-arc cathodic evaporation (CAPVD). The bias potential was -200 V and -500 V during the deposition process. The nanograin structure with small average crystallite size of about 7.5 nm and [110] preferred orientation were observed in the coatings deposited at high substrate bias (-500 V). Crystallites of about 41.6 nm in size and a preferred orientation with [111] axis were formed in coatings when the bias was -200 V. In this case, the nanostructured coating demonstrated the maximum hardness H = 49.5 GPa (superhardness). Additionally, the studied samples exhibited high abrasion and crack resistance, low wear at tribological tests. The testing of a polycrystalline cubic boron nitride (PCBN) cutter plate covered with (TiAlSiY)N coating fabricated at -200 V revealed an increase in the coefficient of resistance during cutting by 1.66 times in comparison with the base tool material.