Multiphase films bearing Ti_2AlN by pulse plasma hollow cathode nitriding

摘要

This study aims to resolve the wear resistance and extend the use of titanium aluminides. A novel method of obtaining multiphase films bearing Ti_2AIN on the Ti-AI alloys is put forward. The Ti_(1-x)Al_x (x=0-25, 0-33 and 0-47) alloys were nitrided in a pulse plasma hollow cathode environment at 800-900°C for various durations in a mixture of 50%N_2 and 50%H_2 under pressures of 1-50-3-00 torr. The results show that the nitriding gas pressure has a strong influence on the phase structure of the surface films. The forming phases in the films are mainly composed of Ti_2AIN and TiN compounds. The presence of Ti_2AIN in the wear tracks apparently reduces the friction coefficient of the samples. The hardened phase TiN in the film improves the wear resistance of the Ti—33AI alloy.