ULTRASONIC QUALITY CONTROL OF SOLDERED AND WELDED JOINTS IN ELECTRICAL CONTACTS

Electrical contact units are components of electrical switching devices, which are widely used in many industries, including defense, aviation, space, where not only the performance of the equipment, but also, often, people’s lives depend on the quality of the components used. Therefore, the quality of electrical contact units is a priority in the production of switching devices. The purpose of the study is to demonstrate the possibility of using ultrasonic testing to assess the quality of soldered and welded joints in electrical contact assemblies. Materials and methods. The quality of the connections was studied on various contact assemblies using the ultrasonic testing method with a special transducer. To confirm the results of ultrasonic testing, metallographic studies and mechanical tests of the contact assemblies were also carried out. Results. A comparative analysis of the results of ultrasonic quality control of soldered and welded joints with the results of metallographic studies and mechanical tests of contact parts for shear along the surface of the joints on three different types of contact units is carried out. The presence of a direct correlation between the results of ultrasonic quality control of soldered and welded joints and the results of their metallographic studies and mechanical tests on all the electrical contacts under study is shown. Possible causes of low quality and strength of connections in individual contact units under study are analyzed. Conclusions. The possibility of using the ultrasonic testing method to assess the quality of soldered and welded joints in electrical contact assemblies is shown. The results of ultrasonic testing are confirmed by metallographic studies and mechanical tests of the contact assemblies.