Microstructure and Mechanical Properties of TiAlON/TiAlN/TiAl Films

Abstract

TiAlON/TiAlN/TiAl hard films are prepared by multi-arc ion plating technology using the Ti-50Al (at%) alloy target. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface and cross-fracture compositions and the phase structures of the as-deposited TiAlON/TiAlN/TiAl hard films are observed and measured by scan electronic microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The mechanical properties, including micro-hardness and adhesive strength between film and substrate, of the as-deposited TiAlON/TiAlN/TiAl hard films are investigated. The effects of oxygen partial pressure on the as-deposited films are discussed. It is revealed that the increase of oxygen decreased liquid droplets distribution density to some extent, caused complicated phase structure. Nevertheless, the good adhesive strength and the improved hardness with a maximum of 3900HV are achieved.