绿色建筑铝合金型材的热处理与力学性能

Heat treatment and mechanical properties of green building aluminum alloy profile

采用金相显微镜、扫描电镜、透射电镜和拉伸试验机等手段,研究了固溶时间、时效温度和时效时间对Al-1.0Mg-0.6Si-0.25Cu合金显微组织、硬度和拉伸性能的影响。研究结果表明,固溶温度540℃、固溶保温时间60 min时,合金中黑色块状Mg2Si初生相基本回溶至基体,而继续延长保温时间,白色条状或块状AlFeSi相不会发生明显变化,而晶粒发生粗化;随着固溶保温时间的延长,合金的抗拉强度、屈服强度和硬度都呈现先增加而后减小的特征,断后伸长率先减小而后增大;随着时效温度升高,时效时间延长,合金中细小第二相数量不断增多,晶粒有所粗化,合金的抗拉强度、屈服强度和硬度都呈现先增加而后减小的特征,断后伸长率先减小而后增大。Al-1.0Mg-0.6Si-0.25Cu合金适宜的固溶保温时间为60 min、时效温度为180℃、时效时间为7 h。

Effects of solution treatment time,aging temperature and aging time on microstructure,hardness and tensile properties of Al-1.0Mg-0.6Si-0.25Cu alloy were studied by means of metallographic microscope,scanning electron microscopy,transmission electron microscopy and tensile testing machine.The results show that when the solid solution treatment temperature and holding time are 540℃and 60 min,the primary phase of black bulk Mg2Si in the alloy basically dissolves back to the matrix;when the holding time is prolonged,the white strip or bulk AlFeSi phase does not change obviously,but the grain coarsens;the tensile strength,yield strength and hardness of the alloy first increase and then decrease,and the elongation first decreases and then increases.With the increase of aging temperature and aging time,the number of fine secondary phase in the alloy increases and the grain coarsens,the tensile strength,yield strength and hardness of the alloy first increase and then decrease,and the elongation first decreases and then increases.It is concluded that the proper solution treatment holding time of the Al-1.0Mg-0.6Si-0.25Cu alloy is 60 min,the aging temperature is 180℃,and the aging time is 7 h.