固溶后冷轧变形量对2195铝锂合金组织和力学性能的影响

Effect of Cold Rolling Deformation on Microstructure and Mechanical Properties of Solution-treated 2195 Al-Li Alloy

对固溶后的2195铝锂合金挤压板材进行5%~25%的冷轧变形,并对变形后的板材进行了人工时效处理,通过组织分析和拉伸实验,研究了固溶后冷轧对2195铝锂合金挤压板材组织和性能的影响.结果表明:当冷轧变形量增加到20%时,板材厚度方向局部纤维状组织之间呈45°剪切带;当冷轧变形量继续增大到25%时,剪切带出现在板材整个厚度方向上.冷轧板材经过时效处理(155℃保温28 h)后,屈服强度、抗拉强度和延伸率随冷轧变形量的增加均先升高后降低.冷轧变形量为10%时,试样时效后的屈服强度、抗拉强度和延伸率达最大值,分别为575,604 MPa和13.7%.时效试样的屈强比先由未冷轧变形的90.8%增加到20%冷轧变形量的97.4%,再略降至25%冷轧变形量的97.1%.综合分析组织和力学性能,认为2195铝锂合金挤压板材固溶后的冷轧变形量应控制在10%左右.

The extruded and solution-treated plates of 2195 Al-Li alloy were cold rolled by the reduction of 5%~25%followed by an artificially aging process,and then the effect of cold rolling deformation on its microstructure and mechanical properties were studied through microstructure analysis and tensile test.The results show that the 45°shear bands begin to appear among some fibrous structures in the thickness direction of the plate after the reduction reaches 20%.Furthermore,the bands can be distributed in the whole thickness of the plate when the reduction increases to 25%.After aging treatment(155℃for 28 h),the yield,tensile strength and final elongation of the cold-rolled plates firstly increase and then decrease with the reduction increase.When the reduction is 10%,the yield,tensile strength and final elongation of the plate reach their maximum values of 575 MPa,604 MPa and 13.7%,respectively.After aging,the yield-tensile strength ratio of the sample increases from 90.8%to 97.4%with the reduction from 0 to 20%,and then slightly decreases to 97.1%with further increasing reduction to 25%.Therefore,for the extruded and solution-treated 2195 Al-Li alloy plate,the reduction of cold rolling should be controlled around 10%.