METHOD OF ULTRASOUND FLAW DETECTION IN STRUCTURE OF MATERIAL PRODUCTS Russian patent published in 1995 - IPC

FIELD: non-destructive flaw-detection. SUBSTANCE: method involves generation of pulses of compressional waves by wide-band ultrasound source. Plane- parallel rod, which length conform to equation l_rod≥ 2l/v_rod/v, where l is length of tested product, v_rod and V are speeds of compressional waves in rod and tested product respectively, is used for several alternations of carrier frequency which are fit into each electric pulse generated by ultrasound source. Then ultrasound source is moved along product surface and is rotated around its axis. Echo pulses that are reflected from place, where rod and tested product have contact, are received. Then second echo pulses are subtracted from first ones. Flaws in structure of tested product are judged by functional characteristics and shape of change of envelope of differential signal. EFFECT: increased reliability of flaw detection due to detection of three-dimensional defects having various geometric sizes. 1 dwg