铝锂合金2091锻造材料力学性能研究
来源期刊：中南大学学报(自然科学版)1992年第4期
论文作者：章四琪 罗琴英 黄宝忠
文章页码：436 - 440
关键词：铝锂合金; 锻造; 力学性能
Key words：AI-Li alloy; forging; mechanical properties
摘 要：研究了铝锂合金2091锻造材料的力学性能.结果表明,固溶处理后经5%冷锻变形和170℃、2h+190℃、6h双级时效,可使材料获得较好的强度和塑性;预冷变形使时效过程增强,达到峰值强度的时效时间缩短;在时效时间为12h情况下,KIC值随时效温度的升高而降低.预冷变形促使过渡相S’(Al2CuMg)沿位错亚结构弥散析出、抑制δ’(Al3L3)相粗化和δ’的无析出带(PFZ)变窄,是铝锂合金锻造材料强塑性改善的重要原因.而提高时效温度,加速扩散过程,促进δ’相粗化和PFZ变宽,则是KIC降低的可能原因.
Abstract: The mechanical properties of a forged Al-Li alloy were investigated. The results show thatbetter strength-ductility of the alloy may be obtained by the treatment of 5% prior cold forgingand subsequently with 170'C, 2 h and 190 C, 6 h double aging after solution treatment, tile priorcold forging enhances aging response of the alloy KIc values decrease with the increase of agingtemperature from 150'C to 190'C for the same period (12 h). The main reasons for improvingstrengthductility of the alloy are the dispersed precipitation of the second strengthening phase SA12CuMg along dislocation and substructure introduced by the prior cold forging, the inhibitionof coarsening of c<sup> phase(AlaLi) and the narrowning width of PFZ. The possible reasons of decreasing KIC values are the promoted diffusion, coarsening δ' phase and widening PFZ when theaging temperature is increased.
