Synthesis of ZrAlN coatings with thermal stability at high temperature

摘要

Dry machining will result in elevated temperatures at the tool surface (800-1000 deg C). So, coating materials that can provide protection for cutting tools at these temperatures are of great technological interests. ZrAIN coating is proposed to possess high-temperature stable structural and mechanical properties due to the addition of the alloying element. ZrAIN coatings were grown using a dc reactive magnetron sputtering. The XRD and nano indenter were employed to investigate the effects of reaction gas partial pressure and substrate bias on structural and mechanical properties, as well as high-temperature stability. The ZrAIN coating, when deposited under optimum conditions (-37 V substrate bias and 2 X 10~(-5) Pa N_2 partial pressure), showed smooth surface with thermal stable hardness. Its internal stress was relaxed from 2.2 to 0.7 GPa after annealing. Formation of Al_2O_3 and ZrO_2 crystalline phases should be related to thermal stability of the coatings.