7150高强铝合金均匀化退火工艺研究

Study on Homogenizing Annealing of 7150 High Strength Aluminum Alloy

摘要: 采用OM、SEM、EDS分析、硬度测试等手段，研究了不同均匀化退火工艺对挤压态7150高强铝合金组织与硬度的影响。结果表明：挤压态7150铝合金组织由α-Al基体、细小颗粒状的MgZn₂相和粗大的Al₂CuMg相组成，第二相体积分数为25.8vol%。经465℃×30h均匀化退火的7150铝合金中MgZn₂相基本溶入基体，晶界处仍残余有少量的Al₂CuMg相，第二相体积分数下降到12.1vol%。经450℃×24h+480℃×4h双级均匀化退火的合金组织中第二相体积分数最少，为7.6vol%，均匀化效果最好，其硬度达到149.4HV。

Abstract: The effects of homogenizing annealing on the microstructure and hardness of 7150 high strength aluminum alloy were studied by means of OM, SEM, EDS analysis and hardness test. The results show that the microstructure of extruded 7150 aluminum alloy consists of α-Al matrix, fine granular MgZn₂ phase and coarse Al₂CuMg phase, and the volume fraction of the second phase is 25.8 vol%. MgZn₂ phase in 7150 aluminum alloy after homogenizing annealing at 465 ℃×30 h is basically dissolved into the matrix, and a small amount of Al₂CuMg phase remains at the grain boundary, and the volume fraction of the second phase decreases to 12.1vol%. After annealing at 450 ℃×24 h+480 ℃×4 h, the volume fraction of the second phase is 7.6vol%, the homogenization effect is best, and the hardness reaches 149.4 HV.