2195铝锂合金应力松弛时效成形工艺制度

Stress Relaxation Aging Forming Process System of 2195 Al-Li Alloy

以2195-T8态铝锂合金为研究对象,探究工艺参数对其应力松弛时效行为的影响规律。试样经过固溶、淬火,进行不同预变形、时效温度及时效时间条件下的应力松弛时效实验。通过室温拉伸,测得应力松弛时效后试样的力学性能。基于正交试验的极差分析和方差分析,探究了预变形、时效温度和时效时间3个工艺参数对应力松弛量、屈服强度和延伸率的影响权重占比;进一步研究发现预变形不仅可以提高2195铝锂合金时效后的强度,还降低了应力梯度对材料力学性能不均匀性的影响;查明了实现2195铝锂合金应力松弛时效形性协同制造的合理工艺制度:180℃+4%预变形+时效时间12~16 h。研究工作为大型铝锂合金构件应力松弛时效形性协同制造工艺窗口的确定提供了重要支撑。

In this paper,2195-T8 Al-Li alloy is taken as the research object to explore the influence rules of process parameters on its stress relaxation aging behavior.After solid solution and quenching,the samples are subjected to stress relaxation aging experiments under different pre-deformation,aging temperature,and aging time conditions.The mechanical properties of the samples after stress relaxation aging are measured by stretching at room temperature.Based on the range and variance analyses of the experimental results,the influence weight proportions of three process parameters,i.e.,aging temperature,pre-deformation,and aging time,on the stress relaxation amount,yield strength,and elongation are investigated.Further research shows that the pre-deformation can not only improve the strength of 2195 Al-Li alloy after aging,but also reduce the stress gradient influence on the mechanical property nonuniformity of the material.The reasonable technological system for the precision-property collaborative manufacturing of 2195 Al-Li alloy with stress relaxation aging is found out:180℃+4%pre-deformation+aging time in the range from 12 h to 16 h.The research work provides an important support for the determination of the precision-property cooperative manufacturing process window of large Al-Li alloy components with stress relaxation aging.