AA7075板材热处理的增塑机制及成形性能

结合生产工艺过程,研究了成形所需固溶处理、工序衔接所需自然时效、性能恢复所需人工时效对板材力学性能和成形性能的影响;通过金相显微镜、扫描电子显微镜和能谱分析等手段,探索热处理对板材显微组织与宏观力学性能的影响。结果表明：AA7075板材经固溶(480 ℃,0.5 h)水淬且自然时效处理后,最大力总伸长率提高85%、屈服强度降低60%,后经人工时效(120 ℃,12 h)处理,板材可完全恢复力学性能;固溶后,板材成形极限大幅提高,回弹比率显著减小;后继时效处理对弯曲角变化影响微弱。

Plasticizing Mechanism and Formability of AA7075 Sheet Heat Treatment

Combined with production processes, effects of solution treatment required for forming, natural aging required for process connection, and artificial aging required for performance recovery on the mechanics properties and forming properties of the sheets were studied. The influences of heat treatment on the microstructure and macroscopic mechanics properties of the sheets were investigated by optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The results show that the percentage of total elongation at maximum force increases by 85% and yield strength decreases by 60% after the AA7075 sheets are heat-treated with solution treatment(480 ℃, 0.5 h) and natural aging. The sheets may restore mechanical properties completely after artificial aging(120 ℃, 12 h). The forming properties of the sheets are greatly improved and the rebound rate of the sheets is reduced significantly after solution treatment. The influence of subsequent aging treatment on the bending angle changes are weak.