预变形及时效处理对7055铝合金组织和性能的影响

Influence of Pre-Deformation and Aging on Properties and Microstructures of 7055 Al Alloy

摘要:

通过拉伸试验、金相观察、X射线衍射以及TEM观察，研究了7055铝合金固溶处理后，经不同程度冷变形和时效后的力学性能和电导率的变化以及相应的微观组织变化特点。实验结果表明，对于冷变形再T6时效的7055铝合金，随变形量的提高，强度先略有上升，而后缓慢下降。RRA态合金强度随变形量增加而持续下降。随变形量的增加，冷轧态7055铝合金的电导率逐渐下降，而T6和RRA态合金的电导率却逐渐上升。在同样变形量条件下，RRA态合金具有最高的电导率。这些变化与变形引入的位错所产生的晶格畸变以及位错促进粗大平衡相析出有关。

Abstract:

The mechanical properties, electrical conductivity and microstructures of 7055 aluminum alloy in various cold rolling reductions and tempers were investigated on the basis of tensile test, optical microscopy, X-ray diffraction and TEM. The results showed that the strength of 7055 alloy could be increased slightly after cold rolling and T6 aging at a smaller reduction, then decreased at a heavier rolling reduction, and always reduced with the increase of rolling reduction for the RRA temper alloy. The electrical conductivity of cold rolled 7055 alloy decreased with the increase of rolling reduction and increased for T6 and RRA temper alloys due to the lattice distortion and coarse precipitates from dislocations.