X-Ray Stress Measurement and Mechanical Properties of TiN Films Coated on Aluminum and Aluminum Alloy Substrates by Arc Ion Plating and Ion Beam Mixing

抄録

TiN coatings on cutting tools have greatly succeeded in prolongation of tool lives. In the present study, TiN film deposition was tried on a surface of aluminum and aluminum alloy substrates by means of an arc ion plating (AIP) method and an ion beam mixing (IBM) method. The aim is to develop aluminum-based materials having strong wear resistance. In order to examine the hardness and residual stress of TiN films, the bias the voltage and N₂ gas pressure were varied in the AIP treatment and the titanium deposition rate was changed in the IBM treatment. Vickers hardness test revealed high values (HV=1800-2400). The TiN films coated by the AIP and the IBM methods exhibited very high {111} and {110} preferred orientations, respectively. The two-exposure X-ray stress measuring method was used to measure residual stresses in the TiN film. Large compressive residual stresses of -6.3--2.3GPa were developed at lower N₂ gas pressures for the AIP method and at higher Ti deposition rates for the IBM method. A wear experiment was also made with a ball-on-disk type wear testing machine. The depth and the width of wear traces on the surface of specimens were greatly reduced when TiN coatings were applied.