固溶处理对7A55铝合金断裂韧性的影响  

Effect of solution on fracture toughness of 7A55 aluminum alloy

作　　者：刘文辉[1] 张新明[1] 李惠杰[1] 刘胜胆[1] 黄振宝[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2007年第1期41-45,共5页Journal of Central South University:Science and Technology

基　　金：国家重大基础研究资助项目(2005CB623706);国际科技合作重点项目(2004DFA00200)

摘　　要：采用金相组织观察、拉伸实验、Kahn撕裂试验、扫描电镜、透射电镜等方法研究固溶处理对7A55铝合金断裂韧性的影响。研究结果表明:固溶温度对7A55铝合金断裂韧性影响显著,7A55铝合金在450～490℃时固溶,随着温度上升,可溶性粒子减少,断裂韧性增加,到480℃时断裂韧性达到最大值;当温度超过480℃时,由于晶粒的长大,断裂韧性又开始下降;7A55铝合金有很大的淬火敏感性,当以慢速淬火时,晶界非共格析出物尺寸粗大,对断裂韧性不利。The effect of solution on fracture toughness of 7A55 aluminum alloy was investigated by optical microscopy, tensile test, Kahn tear test, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results show that solution temperature has significant effects on fracture toughness of 7A55 aluminum alloy. The solution temperatures are in the range of 450-490 ℃, the soluble particles decrease with the increase of solution temperature, and the fracture toughness increases and reaches the peak at 480 ℃, then drops because the grain grows. 7A55 aluminum alloy has a high quenching sensitivity, and a slow quenching rate induces coarse precipitates, which is harmful to fracture toughness of the alloy.

关 键 词：7A55铝合金 断裂韧性 固溶处理 Kahn撕裂实验 

分 类 号：TG166[金属学及工艺—热处理]