Effect of heating time on bonding interface, atom diffusion and mechanical properties of dissimilar titanium joints produced by thermal self-compressing bonding
(1. Aeronautical Key Laboratory for Welding and Joining Technologies, AVIC Beijing Aeronautical Manufacturing Technology Research Institute, Beijing 100024, China;
2. School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China)
Abstract: Solid-state bonding between pure titanium and Ti6Al4V (TC4) alloy was conducted by a new bonding method named as rigid restraint thermal self-compressing bonding. Effects of heating time on bonding interface, atom diffusion and mechanical properties of the joints were studied. Results show that atom diffusion between pure titanium and TC4 alloy significantly takes place during bonding. The diffusion depths of Al and V in pure titanium side are increased with increasing heating time. Due to the enhancement of atom diffusion, bond quality of the bonding interface is improved along with the increase of heating time. The heating time seems to have little effect on microhardness distribution across the joint. However, the tensile strength and ductility of the joint have close relation to heating time. Prolonging heating time can improve the tensile strength and ductility of the joint, especially the latter. When the heating time increases to 450 s, solid-state joint with good combination of strength and ductility is attained.
Key words: dissimilar titanium alloys joining; rigid restraint thermal self-compressing bonding; atom diffusion, mechanical properties