Evaluation of tensile strength and fatigue strength of commercial pure aluminum/tough pitch copper friction-welded joints by deformation heat input

Abstract

The relationships between the deformation heat input at the upset stage and joint strength, and between upset burn-off length and joint strength were examined on 1050 pure aluminum to C1100 tough pitch copper friction-welded joints. Joint quality was evaluated from tensile strength and fatigue strength. It was found that the deformation heat input at the upset stage or the upset burn-off length could be correlated well with joint strength, and when the deformation heat input at the upset stage or upset burn-off length exceeded a certain value, a stable tensile strength was obtained. The mixing layer consists of intermetallic compounds and A1050 was formed at the weld interface, and joints having thick mixing layer fractured at the weld interface. Joint efficiencies of sound joints for the fatigue limit of the A1050 base metal was 88–100%. Judging from the fatigue limit, the sound joints could be produced when either the deformation heat input at the upset stage or the upset burn-off length exceeded a certain value.