Effect of heat treatment process on the microstructure of the interface of Ti/Al laminated composite

Abstract

ABSTRACT In this paper, the effect of heat treatment process on the microstructure of the interface of Ti/Al laminated composite was studied. After explosive welding, the interface region of the Ti/Al laminated composite was composed of the bonding zone and the local melting zone. The bonding zone of the composite exhibited a wave morphology. The local melting zone was formed at the vortex of the wave bonding zone with some initial defects such as voids and microcracks, which was composed of different kinds of Ti-Al intermetallic compounds. The composite was heat-treated at 823 K, 848 K and 873 K. With the heat-treated time increased, the thickness of the bonding zone gradually increased. Based on the growth kinetics, the growth mechanism of the intermetallic compound in the bonding zone had been explained. The growth of the bonding zone was mainly controlled by the reaction mechanism and the diffusion mechanism in the early stage and the later stage, respectively. In addition, as the heat-treated time increased, the intermetallic compounds in the local melting zone were gradually transformed into Al3Ti, and the initial defects disappeared.