Influence of rolling temperature on microstructural evolution and mechanical behavior of AZ31 alloy with accumulative roll bonding

The effect of rolling temperature on AZ31 alloy with accumulative roll bonding (ARB) had been investigated. The results showed that dynamic recrystallization occurs and forming shear bands in the direction of shear stress, exhibit the shape that width decreases from the surface to the inside when ARB at 450 °C. Strength was increased result by strain hardening after ARB process, with compromise of elongation was attributable to the internal crack. Microhardness was enhanced after ARB, while decreasing with the increase rolling temperature. Because of the formation of shear band, microhardness of outer plate was lower than inner plate. Interface bonding strength was increased by improving ARB temperature. Interface bonding is a process in which dynamic recrystallization occurs on both sides of the interface, fine recrystallized grains constantly swallowed and replace the original grains until the interface is annihilated. Crack initiation in shear band and extends along the shear band.