Influence of Intermediate Heating in Cross Accumulative Roll-Bonding Process on Planar Isotropy of the Mechanical Properties of Commercial Purity Aluminium Sheet

Abstract

In this study, the cross accumulative roll-bonding (CARB) process, as an improved technique of the conventional accumulative roll-bonding (ARB), was conducted on the AA1050 sheet up to 10 passes in two processing modes. The specimens were either preheated before the rolling step of CARB passes and promptly roll bonded (warm CARB) or were processed at room temperature (cold CARB). The microstructure of samples was characterized using a scanning electron microscope. The effect of intermediate heat treatment on the planar homogeneity of the mechanical properties in the CARB (and even ARB) deformed sheets has not been examined yet. Hence, the present research focuses on the comparison of the planar isotropy of tensile properties between warm and cold CARB products. Also, the uniformity of microhardness distribution throughout the thickness of samples was evaluated. The warm CARB presented higher elongation, lower tensile strength and microhardness with more uniformity of the microhardness distribution, and also premier planar isotropy of the mechanical properties than the cold CARB.