过饱和7050铝合金固溶体中第二相粒子的析出动力学

Precipitation kinetics of second-phase particles in supersaturated solid solution of 7050 aluminum alloy

利用差示量热法(DSC)并结合JMA方程与双峰分离法对过饱和7050铝合金固溶体中第二相粒子的析出动力学进行分析和计算。研究结果发现:GPⅠ区(367±1)K,η′相(507±1)K和η相(524±1)K的激活能分别为(76.5±0.6),(183.6±2.1)和(666.6±16)kJ/mol,常数k0分别为5.48×1010,5.48×1018和3.14×1066/s,同时得到了其相应的组织转变动力学方程。通过计算发现在本实验条件下,7050铝合金固溶淬火后在393 K时效的峰值时间约为280 h,而在453 K时效的峰值时间约为0.5 h。该计算结果与实验结果十分吻合,其对7050铝合金固溶淬火处理后的人工时效过程有一定的指导作用。

The precipitation kinetics of second-phase particles in supersaturated solid solution of 7050 aluminum alloy was investigated by a combination of differential scanning calorimetric （DSC） techniques with Avrami-Johnson-Mehl （AJM） equation and multi-peak separation. The result shows that, the activation energy of GP I （367±1） K, η＇ phase （507±1） K and t/phase （5244-1） K are （76.54-0.6）, （183.64-2.1） and （666.64-16） k J/tool, respectively. The constant of k0 are 5.48 × 1010, 5.48× 1018 and 3.14× 1066/s. The equations of the corresponding kinetic are gained at the same time. In this experimental condition for calculating, the peak strength time of the quenched 7050 aluminum alloy aged at 393 K is about 280 h, while at 453 K is about 0.5 h. And the calculated results agree well with the experimental results. So it is significant to direct the artificial aging treatment after quenching.