热轧变形量对7085铝合金微观组织与力学性能的影响

Effect of hot rolling deformation on microstructures and mechanical properties of aluminum alloy 7085

实验研究了热轧变形量对7085铝合金微观组织、力学性能及位错密度的影响。结果表明,增加热轧变形量能显著影响合金的微观组织和力学性能。随着轧制变形量的增加,合金内部引入大量位错并在晶界处形成位错塞积,合金再结晶程度逐渐增大（当变形量达到80%时,发生完全再结晶）,晶粒被显著拉长,晶界处的粗大第二相被破碎,时效态平均晶粒尺寸减小,室温强度增大。而当轧制变形量增加到90%时,晶粒逐渐粗化,导致室温强度有所降低。通过X射线衍射分析数据计算可知,当变形量达到80%时,合金内位错密度最高,位错对强度的贡献也达到峰值。

The effect of hot rolling deformation on microstructures,mechanical properties and dislocation density of aluminum alloy 7085 was investigated by experiment. The results show that increasing hot rolling deformation amount can significantly affect the microstructure and mechanical properties of the alloy. With the increase of rolling deformation,a large number of dislocation is introduced inside the alloy which cause the formation of dislocation pile-up at the grain boundaries,the recrystallization degree increases gradually（full recrystallization occurs when the deformation is 80%）,the grains are elongated significantly,the coarse second phase is broken up,the mean grain size of aging state decreases,and the strength at room temperature increases. However,when the deformation increases to 90%,the grains become coarse gradually and the strength at room temperature decreases. It is calculated by X-ray diffraction data that when the deformation is 80%,the dislocation density is the maximum and its contribution to strength reaches the peak.