1983 年 4 巻 3 号 p. 149-156
New techniques are described for characterizing solid surfaces by means of acoustic microscopy. Acoustic microscopy can visualize subsurface layers of a solid unobservable with optical or electron beam techniques. This advantage makes possible the evaluation of ceramic fracture toughness, a property that determines wear and erosion resistance. Also possible is the study of the delamination mechanism of PVD films under repeated sliding contacts. Another advantage of acoustic microscopy is that it can measure the velocity and attenuation of surface acoustic waves on a small area of solid surfaces. These waves penetrate into the solid by about one wavelength and can probe the elastic properties of a surface layer whose thickness is determined by the acoustic frequency. Good correlation was found between the hardness of TiN PVD film and the increase in velocity of the surface acoustic waves, or between the hardness of heat-treated steel and surface wave attenuation. It is proposed that the combined application of these new techniques will serve as a comprehensive means of characterization of metals and ceramics.