Influence of explosive welding parameters to the structure of interface in brass-invar thermobimetal

The influence of kinematic parameters of explosive welding of brass L63 with Invar 36N on the quality of the layers and the structure of the welding zone of thermobimetal grade TB 1353 (TB 130/17) was experimentally studied. It is shown that, since alloy L63 containing a fusible component (zinc) is used as an active layer in the thermobimetal, the choice of welding mode should be carried out taking into account the prevention of the “ejection” effect. In this case, the flow of shock-compressed gas with high pressure, moving in the gap at high speed, carries a low-melting phase; therefore, the strength of the connection is reduced up to full loss of strength, and also the phase (chemical) homogeneity of the layers in the welding zone is violated. Joints of the thermobimetals were tested with an ultrasonic flow detector. The structure of the welding zone was investigated by optical and electron microscopy on a metallographic section. The toughness of layers during breaking off was determined on ring samples. Tests on lateral bending and bending of the cladding layer inside were carried out. The optimum mode providing the explosive welding in the solid phase with 100% continuity of the adhesion layers and toughness of layers during breaking off at the level of the strength of brass and the high-grade structure of the weld zone was determined.