Characterization of crystal structure in the bonding interface between TC17 and TC4 alloys

摘要

The Ti-5Al-2Sn-2Zr-4Mo-4Cr (TC17)/Ti-6Al-4 V (TC4) bonding interface at a bonding temperature of 820 degrees C, bonding pressure of 10 MPa and bonding time of 10 min was obtained, in which sufficient elemental diffusion occurred between TC17 and TC4. Special attention was paid to characterize the crystal structure in TC17/TC4 bonding interface via transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) techniques. The results showed that face-centered cubic titanium occurred in TC17 side of bonding interface, in which the face-centered cubic titanium and body-centered cubic titanium showed Kurdjumov-Sachs orientation relationship. Based on the orientation relationship and lattice parameter, the expansion of unit cell from body-centered cubic titanium to face-centered cubic titanium was about 2%. Besides, the disordered lattice appeared on the phase boundary between face-centered cubic titanium and hexagonal closed-packed titanium in TC4 side of bonding interface.