Structural properties of Ti/Al clads manufactured by explosive welding and annealing

The paper presents a comprehensive study on the titanium and aluminum clads manufactured by explosive welding. Particularly, the microstructure evolution of the Al/Ti interface at 825 K and various annealing time was examined. In the state directly after explosive welding, the wavy morphology of the connection was locally composed of four intermetallic phases: TiAl$_{3}$, TiAl$_{2}$, TiAl and Ti$_{3}$Al, forming small and peninsula-like morphology(vortex). The annealing process mainly caused growth of the TiAl$_{3}$ phase as a continuous layer. The studies of the growth kinetics showed four stages: incubation period (up to 1.5 h), the growth govern by the chemical reaction(1.5–5 h), mixed mechanism of chemical reaction and volume diffusion and finally the volume diffusion growth(36–100 h). The orientation maps revealed significant differences concerning the microstructure and texture of welded metals. Directly after explosive welding process, aluminum possessed a typical rolled texture, while intitanium intensive twinning was observed. After annealing, due to the secondary recrystallization, abnormal grain growth was observed in aluminum, while in titanium annihilation of deformation twins took place. The hardness profile made across the welded area after annealing showed the highest values between 365–750 HVin vortex regions at the Al/Ti interface