Fabrication and characterization of a bimetallic Al/Cu tube using the tube sinking process

Abstract

In this work, two types of bimetallic tubes were fabricated from aluminum alloy and pure copper using the tube sinking process. The joint quality of the bimetallic tubes was evaluated using the so-called push experiment to determine the bonding shear strength. In addition, different microstructural studies were conducted in order to study the interface character of the layers. It was found that the bonding shear strength of the aluminum-clad copper was slightly higher than that of the copper-clad aluminum. Also, the former exhibited lower bonding shear strength variation than the latter. The discontinuous intermetallic components were detected at the latter interface for both types of bimetallic tubes. Also, it was interesting to note that a relatively thick aluminum oxide layer was found to be formed partially at the copper-clad aluminum tube layer interface. Signs of the cold pressure welding mechanism based on the film theory were indicated in aluminum-clad copper, whereas localized oxidation and wear phenomenon between the aluminum and copper layers deteriorated the bonding strength in copper-clad aluminum.