Investigating the properties of bimetallic aluminum-clad copper tubes produced by friction stir welding

Highlights: • Using FSW method, bimetallic Aluminum-clad copper tube was produced. • Effect of welding parameters on microstructural properties was investigated. • Increasing the rotational speed increases the hardness in the stir zone. Using the Friction Stir Welding (FSW) method and incorporating a new fixture, copper and aluminum tubes were welded in a lap joint configuration, producing bimetallic copper-aluminum tubes with appropriate interdiffusion. Moreover, the effects of welding parameters such as the rotational and traverse speeds on the macro- and microstructure, the hardness profile, and the shear strength of the samples were investigated. The results showed a stronger joint is achieved by increasing the traverse speed from 30 to 60 mm/min and reducing the rotational speed from 1000 to 710 rpm. Furthermore, it was found that the curvature of the tubes and the difference in their physical properties are quite challenging when welding copper and aluminum tubes using this method.