Enhancing grain refinement and mechanical properties of AA1100/MgAZ31/AA1100 composites by using different roll bonding techniques

Abstract

This paper examines the microstructure and mechanical properties of AA1100/Mg AZ31/AA1100 composites processed by conventional accumulative roll bonding (ARB) and cross accumulative roll bonding (CARB) methods. Based on the results, with an increase in deformation strain, Mg layers gradually lose their continuity in the form of localized necking and fragmentation. However, changing the strain path and pre-annealing the initial sheets could retard and homogenize the plastic instabilities. According to the results of electron back-scattering diffraction (EBSD), applying severe plastic deformation led to refined-grain structures with equiaxed grains. The finer grains were obtained in composites processed by the CARB method following the pre-annealing treatment. Employing this procedure also intensified the basal-type texture and circled its shape. The strong basal texture and grain refinement led to the highest Mg alloy and Al hardness values of 99 and 64 HV, respectively. Furthermore, changing the strain path and pre-annealing treatment increased the elongation by 46% in the seventh pass compared to ARBed samples. Also, this procedure increased the ultimate strength from 375 to 391 MPa and gave rise to yield strength from 164 to 176 MPa.