Effect of Heating Time on Rigid Restraint Thermal Self-Compressing Bonding of TC4 Alloy

TC4 alloy was bonded by a new solid-state bonding process named as rigid restraint thermal self-compressing bonding at different heating time. Effect of heating time on bond interface, microstructure and mechanical properties was investigated through the optical microscope observation, scanning electron microscope analysis and mechanical properties test to the joints produced at different heating time. In the meantime, thermal stress-strain history during bonding was analyzed by finite element analysis. Results show that with the increase of heating time, the dwell time over high temperature, the action time of compressive stress and the transversal compressive plastic strain increase which promote the atom diffusion between butt-specimens and thus the number of voids retained at bond interface decreases. When the heating time is improved to more than 300 s, sound solid-state joint with good bond interface, homogeneous microstructure and good mechanical properties is obtained.,