The effect of hot rolling process on macro-texture and high-temperature mechanical properties of AZ31B alloy modified by Ca and Ce

Abstract

This study examines the high-temperature tensile properties of AZ31 and AZ31-1.0Ca-0.2Ce alloys in different rolling directions. Tensile test results at 250 °C showed that the ductility of AZ31-1.0Ca-0.2Ce alloy increased threefold in the 90° perpendicular direction to rolling direction. Moreover, both strength and elongation values of AZ31-1.0Ca-0.2Ce alloy were higher than those of AZ31. Macro-texture measurements revealed that AZ31 and AZ31-1.0Ca-0.2Ce alloys showed strong and weakened basal texture in the rolling direction, respectively. The combined effect of secondary phases and texture weakening increased the high-temperature ductility (49%) of AZ31-1.0Ca-0.2Ce. In the rolling direction, yield (YS) and ultimate tensile strength of AZ31-1.0Ca-0.2Ce were obtained as 115 and 121 MPa, respectively. These values were higher than AZ31 alloy due to the stronger texture of the non-basal planes. The fracture surface of AZ31 samples proved that the rough and crack-dominated surface led to brittle fracture formation. However, fine-sized dimples resulted in a ductile fracture in AZ31-1.0Ca-0.2Ce samples.