Ultrasonic control of polymers by the echo method is difficult due to the high attenuation of acoustic waves in the material. To eliminate defects in finished products, enterprises are interested in finding a method for controlling internal defects in kaprolon blanks. The paper proposes flaw detection of kaprolon blanks by the echo method. For this purpose, the velocity of propagation of the longitudinal wave and its attenuation in the caprolon were determined, and the dimensions of the near zone for the transducers A111–2.5-K12, A121–2.5-40 (the angle of entry of the longitudinal wave into the caprolon is 31°) were calculated. An ultrasonic flaw detector with a probe pulse amplitude of 480 V is proposed, which is important for monitoring materials with a high attenuation coefficient. AVG-diagrams have been constructed for defects simulating pores. The calculated data showed convergence with the results of flaw detection of nylon samples with an artificial defect.
A.V. Platunov (Wed,) studied this question.