Study on Elastic Constants and Residual Stress of Ceramic Hard Films
Kenji KANEKO, Shigeru YONETANI, Manabu YASUOKA and Hiroyasu TOMODA
Abstract:Recently, for the purpose of increasing the wear resistance of tools, the hard ceramics, TiC or TiN, are coated by the PVD technology on the surface. The physical properties of such deposited thin films differ from those of the bulk materials. In this study, the TiC or TiN films deposited to various thickness on the stainless steel substrate are prepared. The elastic constants of each film in the single and double layers are measured by the mechanical and the X-ray diffraction method. It is found that the elastic constants measured by the X-ray diffraction method are higher than that by the mechanical method. And@then, the elastic modulus and compressive residual stress of each layer in the double-layer coatings are somewhat lower than that of single-layer coatings because of decrease in the texture and the internal strain. Key Words:Elastic constants, Residual stress, TiC, TiN-PVD film, Preferred orientation, Internal strain, Double-layer coating, X-ray diffraction method