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为了研究双级固溶、双级时效处理下的固溶温度对7050铝合金的影响,采用常温拉伸、晶间腐蚀等方法研究了双级固溶、双级时效热处理制度下第二级固溶温度对7050铝合金组织和性能的影响。结果表明,随着第二级固溶温度的升高合金晶粒尺寸逐渐长大,残余第二相不断固溶。495℃时的S相基本固溶,残余第二相体积分数为0.19%,晶粒尺寸较小,合金屈服强度R_(eL)为655 MPa,抗拉强度R_m为694 MPa,伸长率A_(50 mm)为14.40%,综合力学性能最好。温度过高时合金发生过烧,性能减弱。晶间腐蚀从合金外部晶界开始向内部扩展,耐晶间腐蚀性能随着残余第二相的逐渐固溶而增强。
In order to study the effects of solution temperature and solution temperature on 7050 aluminum alloy in two-stage solution treatment, the effects of two-stage solution treatment and two-stage aging treatment on the second-stage solidification Effect of Solution Temperature on Microstructure and Properties of 7050 Aluminum Alloy. The results show that as the second-order solution temperature increases, the grain size of the alloy gradually increases, and the residual second phase continuously dissolves. The phase S at 495 ℃ is solid solution, the volume fraction of residual second phase is 0.19%, the grain size is small, the yield strength R eL is 655 MPa, the tensile strength R_m is 694 MPa, the elongation A_ ( 50 mm) is 14.40%, the best comprehensive mechanical properties. When the temperature is too high, overheating occurs in the alloy and performance is weakened. Intergranular corrosion extends from the external grain boundaries of the alloy to the interior, and intergranular corrosion resistance increases with the gradual dissolution of the remaining second phase.