Microstructures and tensile properties of hot-rolled AZ31-xCa sheets

Abstract

In this study the effects of Ca addition on the rollability, microstructures and tensile properties of AZ31 alloy were evaluated. In Ca containing alloys, reduction ratio and preheating temperature are the most important variables to make good sheet without any crack. The number and length of side crack increased with increasing Ca content. With increasing the reduction ratio per pass and decreasing the preheating temperature, crack initiates easily at the side. The dendritic grains were changed to fine equiaxed grains through hot rolling by dynamic recrystallization. The Al2Ca precipitates which were segregated to grain boundaries during solidification were rearranged parallel to the rolling direction. The tensile properties of hot-rolled AZ31-xCa sheets were decreased slightly by addition of Ca.