退火温度对轧制态Mg-1Li-3Al-1Zn-0.3(Al5Ti1B)合金组织及力学性能的影响

Effect of annealing temperature on microstructure and mechanical properties of rolled Mg-1Li-3Al-1Zn-0.3(Al5Ti1B) alloy

利用光学显微镜(OM)、扫描电镜(SEM)和电子万能试验机研究了热轧及退火态Mg-1Li-3Al-1Zn-0.3(Al5Ti1B)合金板材的显微组织及力学性能。结果表明:合金板材经150℃退火30 min后的组织与热轧态类似,存在大量的孪晶与剪切带,在室温下拉伸时其抗拉强度可达314 MPa,屈服强度为269 MPa,伸长率为24.4%;而经300℃退火30 min后,组织变为细小的再结晶组织,各向异性现象较小,塑性较150℃退火时有所提高,断口呈现韧性断裂特征。

Microstructure and mechanical properties of rolled and annealed Mg-1Li-3Al-1Zn-0. 3 （A15Til B） alloy were analyzed by using optical microscopy （OM）, scanning electron microscope （SEM） and tensile tester. The results show that when annealed at 150 ℃ for 30 min, the microstructure of the Mg-1Li-3Al-1Zn-O. 3 （AISTilB） alloy sheet is similar to the rolled state which has a lot of twins, and shear band, and the tensile strength, yield stress and elongation of alloy are 314 MPa, 269 MPa and 24.4% respectively. When annealed at 300 ℃for 30 min, the rolled alloy experiences static recrystallization and shows a microstructure of finer and uniform equiaxed grains, a lower anisotropy and higher plasticity than that of annealed at 150 ℃, and the tensile fracture features ductile.