Effect of intermetallic compounds (IMCs) on the interfacial bonding strength and mechanical properties of pre-rolling diffusion ARBed Al/Ti laminated composites

Abstract A combination of pre-rolling diffusion process (PR) and accumulative roll bonding (ARB) was applied to fabricate multilayered Al/Ti laminated composite with a great emphasis on the effect of the optimized interface structure on mechanical properties. The evolution of microstructure and mechanical properties during PR process were analyzed. We found that compared to the conventional rolling process (CR), a better combination between strength and ductility was achieved after the PR process, which was attributed to the improved interface bonding. In addition, the inhomogeneous microstructural distribution in multilayered Al/Ti laminated composites indicated that their formation was related to the friction between roller and sheet surface and the inhomogeneous deformation between constituent layers. The annealing behavior at 550 °C for various times in terms of the growth kinetic and structure of intermetallic compound (IMC) and its effect on the mechanical properties were studied. The evolution of the thickness of the IMC layer and quantitative analysis revealed that the growth behavior obeyed a two-stage development for various periods of time. Such unusual growth behavior was attributed to the effect of grain size in the IMC layer, which caused the grain boundary diffusion. Furthermore, an increasing fraction of fined grains, which was introduced by the IMC layer after annealing, strengthened the Al/Ti laminated composite.