中间退火对高镁铝合金组织和力学性能的影响

Effect of intermediate annealing on the microstructure and mechanical properties of high magnesium aluminum alloy

通过拉伸试验和显微组织观察等方法,研究中间退火工艺对高镁铝合金板材组织及力学性能的影响。结果表明:试样在箱式退火炉进行330℃(120~720)min退火后发生完全再结晶,且随保温时间延长,伸长率增加,晶粒趋近圆形,塑性变好;试样经380℃(120~720)min退火后同样发生完全再结晶,但相较于330℃(120~720)min退火,随着保温时间的延长,伸长率增加幅度更小,这与高温退火导致的晶粒粗大有关。模仿气垫式连续退火炉380℃0.17min快速退火后,试样平均晶粒尺寸最小,组织为分布均匀的等轴晶粒,抗拉强度、屈服强度及伸长率均明显高于箱式退火炉退火试样的。

The effect of intermediate annealing process on the microstructure and mechani-cal properties of high magnesium aluminum alloy sheets was studied through tensile testing and microstructure observation.The results show that the sample undergoes complete recrys-tallization after annealing at 330℃(120-720)min in a box annealing furnace,and with the prolongation of holding time,the elongation increases,the grains tend to be circular,and the plasticity improves.The sample undergoes complete recrystallization after annealing at 380℃(120-720)min,but compared to annealing at 330℃(120-720)min,the in-crease in elongation is less with the prolongation of holding time,which is related to the coarsening of grains caused by high-temperature annealing.After rapid annealing at 380 C for 0.17 minutes in a simulated air cushion continuous annealing furnace,the average grain size of the sample is the smallest,and the microstructure is uniformly distributed equiaxed grains.The tensile strength,yield strength,and elongation are significantly higher than those of the box-annealing-furnace annealed sample.