Influence of rolling on microstructure and mechanical properties of vacuum die-casting AM50 alloy sheet

In order to investigate the change of microstructure and mechanical properties of vacuum die-casting AM50 magnesium alloy sheet at different rolling deformation amounts,a small rolling machine was used for mutli-pass rolling.The microstructural observation and tensile tests at room temperature were performed.The results show that the multi-pass rolling can be conducted at room temperature for the present alloy,but the annealing treatment of 310 ℃×10 min is needed between each pass.And the total deformation amount can reach 45%.With increasing the total deformation amount,the rolling streams gradually form.In addition,the grains are elongated,and the average grain size decrease gradually.When the formation amount is 40%,the size of grains is approximately 2～4 μm along the rolling direction,and is about 5～10 μm along the rolling extension direction.With increasing the deformation amount,the plasticity and strength of the alloy increase.When the total deformation amount reaches 40%,the alloy exhibits the highest plasticity and strength values,where the yield strength is 282 MPa,the ultimate tensile strength is 329 MPa and the elongation is 8.8%.