超音波を用いた材料裏面の粗さ評価に及ぼす入射角と周波数の影響

抄録

Three-dimensional back-surface roughness was evaluated by ultrasonic testing. The root-mean-square roughness of back-surface was evaluated by intensity ratio of the wave reflected by rough surface to smooth surface. The effects of incident angle and frequency of ultrasonic were investigated experimentally. Also the relationship between the ultrasonic sound field intensity at back-surface and the range of measured roughness was evaluated. It was found that the measured back-surface roughness by the proposed method corresponds to the roughness within the range where the intensity of sound field is 40 % of the peak value at the back-surface. In order to evaluate back-surface roughness with high accuracy, following factors are important. First, the incident angle should be set 0°. Second, the frequency component used for the measurement should have a high intensity. Third, the change of the intensity ratio should be large when the roughness changes.