淬火速率对7055铝合金组织和力学性能的影响  

Effects of quenching rates on microstructure and mechanical properties of 7055 aluminum alloy

作　　者：刘胜胆[1] 张新明[1] 黄振宝[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《材料科学与工艺》2008年第5期650-653,共4页Materials Science and Technology

基　　金：国家"973"高性能铝材及铝资源的高效利用(2005CB623700);博士点基金(2004053304)

摘　　要：通过常温力学性能测试和透射电镜(TEM)研究了淬火速率对7055铝合金组织和力学性能的影响.结果表明,一定时效条件下,合金的力学性能随淬火速率降低而下降.组织观察发现,淬火速率小时,合金在冷却过程中于A l3Zr粒子和晶界非均匀形核析出粗大η平衡相,降低固溶体过饱和程度,削弱时效强化效果.时效时这些粗大η平衡相继续长大并在周围形成无沉淀析出带.晶界无沉淀析出带宽度随淬火速率降低而增大.对合金力学性能下降的原因进行了分析和探讨.The effects of quenching rates on the microstructure and mechanical properties of 7055 aluminum alloy were investigated by tensile tests and transmission electron microscopy （TEM）. Results indicated that the mechanical properties of the aged alloy were reduced with the decreasing quenching rate. According to microstructure observations, the coarse η equilibrium phases precipitates on Al3Zr dispersoids and grain boundaries during slow cooling, which decreases the supersaturation of the solid solution and the subsequent aging hardening capability. During aging, the coarse η equilibrium phases grow with formation of a precipitate free zone （PFZ） around. The width of grain boundary precipitate free zone increases with decreasing the quenching rate. The reason for lower mechanical properties of the alloy caused by slow quenching was discussed in detail.

关 键 词：7055铝合金 淬火速率 时效 组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]