Abstract :
The occurrence of hydrogen attack in electrolytic copper and in copper deoxidized with phosphorous, during model heating in oil and in friction welded specimens was investigated. Dissimilar-metal joints, i.e. copper/TZM (titanium–zirconium–molybdenum based alloy) joints and copper/austenitic steel joints, were subjected to microstructural examinations and tensile strength tests.
Microcracks near the weld surface, caused by hydrogen attack, were found to occur in the friction welded dissimilar-metal electrolytic copper joints subjected to resoaking at a temperature of 500 °C. This phenomenon did not occur in the joints made using deoxidized copper. The tensile strength of the dissimilar-metal copper joints was tested before and after the additional soaking. It was found that the tensile strength of the friction welded electrolytic copper/steel and electrolytic copper/TZM joints considerably decreased after the additional soaking.
