NON-DESTRUCTIVE TESTING OF JOINTS OF ANTIFRICTION PARTS CRIMPED BY PULSED MAGNETICDEFORMATION

Abstract: Possibilities of non-destructive testing (NDT) methods to assess the quality of permanent joints of powder metal parts were evaluated. Antifriction bushing-bushing couples used in transport braking systems were investigated. The parts made of bronze graphite were crimped by pulsed magnetic deformation by means of electromagnetic equipment with a maximum discharge energy of 30 kJ. The gap between joint parts in the couples was assessed by ultrasonic and radiographic methods. A standard ultrasonic flaw detector Krautkramer USM-25 with an Olympus 4MHzdual-element echo transducer and an industrial x-ray apparatus YXLON EVO 200D were used, correspondingly. In first trial, both methods were equally sensitive to tight and weak connection of joints, however, further studies are necessary to find quantitative estimations of the mechanical integrity. If not limited by the object size, the ultrasonic method is easier in application and can be standardized for use in production lines.