过共晶高硅铝合金固溶工艺因素的优化

通过理论分析和相关试验,对过共晶Al-25Si合金固溶处理阶段的主要工艺因素(如温度、时间)进行了优化,并研究和探讨了其对合金组织和性能的影响.结果表明,固溶处理工艺为510℃×6h时可以获得最佳的固溶处理效果,此时,初、共晶硅及Mg2Si等均获得了最大的固溶度,形态分布得到改善.同时,合金硬度随固溶时间的延长呈现先降后升趋势,在6h时达到最低值99 HBW,相比固溶前降幅超过15％,获得饱和度最大的过饱和α-Al固溶体,成为时效强化作用最大化的先决条件.

Optimization of Solution Treatment Process of Hypereutectic High-Si Aluminum Alloy

Through theoretical analysis and related experiments, the key factors such as temperature and time of the hy- pereutectic Al-25Si alloy during its solution treatment stage were optimized, and their effects on structure and property were also researched and discussed. The results showed that while the process is 510 ℃×6 h, the best effects can be obtained. The primary Si, eutectic Si and Mg2 Si can get maximum solubility, and their morphology and distribution can be improved. Meanwhile, as the solution time increasing, hardness of the alloy firstly increased and then reduced, and dropped to the lowest point 99 HBW while reached 6 h, reduced by more than 15%. The greatest saturation of a-Al supersaturated solid solution was obtained at last, and it would be the prerequisite of the maximization of the ageing strengthening.