Post-deposition annealing effects on microstructure, mechanical and tribological properties of AlCrN films

Abstract

The post-deposition annealing of AlCrN films was conducted in an atmospheric environment for 2 h, with annealing temperatures ranging from 25 to 1000 °C. The microstructure, mechanical, and tribological properties were systematically investigated as a function of the annealing temperature. The results show that the AlN phase in the film began to oxidize at 600 °C, resulting in deterioration of the film's toughness and resistance to plastic deformation. Subsequently, the wear resistance also deteriorated, with the wear rate being nearly 16 times that of the as-deposited film. At 800 °C, the AlN obviously underwent oxidization to form Al2O3. The high temperature annealing promoted the coalescence of Cr on the film surface and caused a reaction with the Al2O3 to form a replacement solid solution of Cr–O–Al, thereby improving the mechanical properties of the annealed films. At the same time, the tribological properties of the films were not significantly deteriorated by annealing at temperatures other than 600 °C, similar to those of the films without any annealing treatment.