Effect of Hot Rolling on Microstructure and Mechanical Properties of Stir Cast AZ 61 Alloy with Minor Additions

Objective: The microstructure and mechanical properties of modified AZ 61 alloy -graphene composite (1wt. %, and 2wt. % graphene) were examined under various conditions of temperature of rolling, number of roll pass, and the amount of deformation. Method: The rolling operation was carried out in a laboratory scale rolling with the initial stock temperature of 4000C. The rolling temperatures were varied and kept at 3500C 3000C, and 2500C. After a few roll passes, the rolled stocks were reinserted within the furnace to make up for the temperature drop. The rolling was continued until the amount of thickness reduction reached 35%. The number of passes varied between 1-4. It was observed that the influence of rolling temperature was quite sensitive to the number of passes to reach the target deformation ~35%. Finding: The study on the structure and properties of hot rolled graphene-reinforced AZ-61 magnesium alloy with minor additions of scandium and calcium is scarce in the literature. Novelty: In the present investigation attempts are made to probe into the effect of graphene reinforcement in AZ-61 alloy that is compositionally modified by minor additions of scandium and calcium with the expectation of a higher level of strengthening. The results showed that maximum hardness values ranged with in 101HV to 106HV whereas, the maxima of tensile and yield strength were found to be 266 .82 MPa and 102 MPa at an elongation percent of 25%. By refining the microstructure, dynamic recrystallization enhanced the samples’ strength and ductility. AZ 61 graphene composite with minor additions of scandium and calcium achieves excellent structural homogeneity and mechanical properties after hot rolling with 2 wt. % graphene rolled at 3500C. Keywords: AZ61 Alloy; Rolling Temperature; Graphene; Composite; Tensile Strength; Deformation Percentage