AZ31B镁合金轧板等温/差温剪切旋压成形的组织性能对比研究

Comparative Study on Microstructure and Properties of AZ31B Magnesium Alloy Rolled Plate by Isothermal/Differential Temperature Shear Spinning

分别进行了AZ31B镁合金轧板等温剪切旋压成形和差温剪切旋压成形实验,对两种成形条件下的工件微观组织和力学性能进行了对比分析。结果表明:200~300℃变形时,镁合金轧板具有良好的等温剪切旋压和差温剪切旋压可成形性;在热旋压成形时,旋压件发生了晶粒细化,但随着旋压温度上升,两种成形方式的旋压件平均晶粒尺寸均增加。在200℃旋压成形时,差温剪切旋压件组织更加细小,力学性能优于等温剪切旋压工件,其轧向(RD)与横向(TD)方向的屈服强度分别为251、233 MPa,抗拉强度分别为304、299 MPa,伸长率分别为21.1%、21.8%;随着旋压温度增至300℃,差温旋压件与等温旋压件的组织状态和力学性能趋于一致。

The experiments of isothermal shear spinning and differential temperature shear spinning of AZ31 B magnesium alloy rolled sheet were carried out respectively. The microstructure and mechanical properties of the workpiece under the two forming conditions were compared and analyzed. The results show that the magnesium alloy plate deformed at200-300℃ has good formability of isothermal shear spinning and differential temperature shear spinning. During hot spinning forming, grain refinement occurs in spinning parts. But with the increase of spinning temperature, the average grain size of the spinning pieces under the two forming modes increases. The grain size of AZ31 B Mg alloy processed by differential temperature shear spinning at 200℃ is smaller than that by isothermal shear spinning, so that the mechanical properties of the workpiece are better than those of the isothermal shear spinning workpiece. The yield strength, ultimate tensile strength and elongation of rolling direction(RD) and transverse direction(TD) reaches 251, 304 MPa, 21.1% and 233, 299 MPa, 21.8%,respectively. With the increase of spinning temperature to 300℃, the microstructure and mechanical properties of differential temperature spinning part and isothermal spinning part tend to be consistent.