Controlling intermetallic compounds formation in commercially pure titanium/electrolytic tough pitch copper dissimilar joint

Abstract

Welding titanium to copper is challenging due to the differences in their thermophysical properties and the formation of intermetallic compounds (IMCs). This study uses gas tungsten arc welding to join commercially pure titanium sheets to electrolytic tough pitch copper without using filler metal, and electrical currents ranging from 80 to 100 A to achieve completely penetrated joints. Microstructure analysis shows the formation of a columnar structure of IMCs at the weld zone, including Ti2Cu, TiCu, Ti3Cu4, Ti2Cu3, and TiCu3. Tensile and three-point bending tests were carried out to investigate the effects of IMCs formed by welding on the mechanical properties. The maximum tensile strength was achieved for the sample with the thinnest intermetallic layer, while brittle fractures were observed in all samples.