Investigation on the Effects of Explosive Welding Parameters on the Mechanical Properties and Electrical Conductivity of Al-Cu Bimetal

The joints of dissimilar materials are widely used in industrial applications due to their technical and beneficial advantages. The dissimilar combination of aluminum and copper is generally difficult for fusion welding. This is because of formation of undesired intermetallic phases which reduces electrical conductivity in the joint interfaces. Therefore, in order to restrict these limitations solid states welding methods such as explosive welding have been suggested. Hence, in this research the effect of explosive welding parameters on microstructure, mechanical and electrical properties were investigated. Stand-off distance and thickness of explosive material were taken as the variable parameters which were affect the microstructure, mechanical and electrical properties. After conducting the Explosive welding process, Microstructural investigations using Optical and Scanning Electron Microscope which is equipped with Energy Dispersive Spectroscopy was performed. Also, for investigation of mechanical properties, hardness test was done. The results of microscopic investigations demonstrated that with increasing the thickness of explosive material, the joint interface was transformed from linear to wavy appearance. Also, the results showed that the Al-Cu interface had a higher hardness in comparison to the hardness of Al and Cu. Evaluations showed that forming the CuAl and CuAl2 intermetallic phases in the joint interface are the reason for increasing the hardness. Electrical resistance values of 0/3, 0/55, 0/38 and 0/40 mS/cm were obtained for Al-1050, Cu, Al-Cu joint interface of A and B samples.