Effect of high temperature on interfacial microstructure and properties of Ti/Al composite plate

Abstract

The effects of high temperature annealing on the interface microstructure and mechanical properties of cast-rolled Ti/Al composite plates were investigated by means of SEM, EBSD, XRD, microhardness, tensile test at room temperature and T-shaped peeling test, etc. The results show that the microstructure of Ti matrix hardly changes during annealing at 550 ℃, while the Al matrix recrystallizes and begins to grow after annealing for 1 h. During the annealing process, the diffusion layer at the interface gradually thickens, and the second phase TiAl3 is generated at 15 min, and the second phase TiAl3 is connected into flakes at 1 h, and the bonding strength of the Ti/Al composite plate interface is decreased rapidly. The bonding strength of Ti/Al composite plate reaches the maximum value of 23.6 N/mm after annealing for 30 min. At 1 h annealing, the tensile strength and elongation of the cast-rolled Ti/Al composite plate reach the peak values of 236 MPa and 27.6%, respectively, which are higher than those of the cast-rolled Ti/Al composite plate.

Keywords

• casting and rolling process
• ti/al clad sheet
• high temperature annealing
• interfacial bond strength
• intermetallic compound