Research on Acoustic Properties of Artificial Inhomogeneities in Calibration Samples for Ultrasonic Testing of Polyethylene Pipe Welds

This article investigates the acoustic properties of artificial discontinuities in reference specimens for the ultrasonic testing of welded joints in polyethylene pipes. An analysis is conducted on the reflectivity of various materials (air, sand, heat-resistant silicate-based sealant, and aluminum foil) and their correspondence to real defects occurring in weld seams. A theoretical analysis of reflection coefficients is performed, along with laboratory studies using digital radiography and ultrasonic testing. The results demonstrate that heat-resistant silicate sealant is the most suitable material for simulating defects, as its acoustic properties closely match those of real inclusions, and its geometric parameters remain stable during the welding process. The use of such specimens enhances the reliability of ultrasonic testing and reduces the likelihood of errors in defect classification.