Methods of testing materials by ultrasonic irradiation

摘要

703,511. Ultrasonic couplings. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Nov. 14, 1951 [Nov. 17, 1950], No. 25721/51. Divided out of 703,480. Class 40 (4) [Also in Group XXXVIII] Ultrasonic sheer waves are transmitted into a body 2 by means of an array of piezo-electric transducer elements 1 and a coupling 4. The array may be of the kind described in Specification 703,508, [Group XL (b)]. The material of the coupling is chosen so that the wave velocity in the coupling is less than the wave velocity in the body 2 and the angle of incidence is such that the sheer component S is transmitted and the pressure component is totally reflected. The angle of incidence can be varied within limits by changing the ultrasonic frequency. Roughened surfaces on the part 7 above a saw cut 5, scatter and absorb the complementary wave Q. Specification 664,763, [Group XXXVIII], also is referred to.