ABSTRACT Ultrasonic melt treatment (UST) is known for refining microstructures including intermetallic compound (IMC)s, and it is expected that the microstructural benefits induced by UST may reduce the time and temperature of solid solution treatment (SST). The effect of UST on SST for an Al-7Si-2Cu-1 Mg alloy was investigated in terms of changes of volume fraction of IMCs in connection with the tensile properties. The results show that UST not only refined the constituent phases but also reduced the volume fraction of IMCs in the as-cast microstructure, which promoted dissolution of Cu and Mg rich IMCs during SST, increasing the yield strength of the alloy. In addition, the SST time to achieve maximum strength was shortened by UST. Without UST, the strength was maximised at 520 °C for 8 hours, while with UST the strength was maximised at 2 ~ 4 hours. The dissolution of the constituent phases upon SST was also discussed.

中文翻译：

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超声熔体处理对Al-7Si-2Cu-1Mg合金固溶处理温度和/或时间的影响

摘要 超声波熔体处理 (UST) 以细化包括金属间化合物 (IMC) 在内的微观结构而闻名，并且预计超声波熔体处理 (UST) 产生的微观结构优势可能会减少固溶处理 (SST) 的时间和温度。根据与拉伸性能相关的 IMC 体积分数的变化，研究了 UST 对 Al-7Si-2Cu-1 Mg 合金 SST 的影响。结果表明，UST不仅细化了组成相，而且降低了铸态组织中IMCs的体积分数，促进了SST过程中富含Cu和Mg的IMCs的溶解，提高了合金的屈服强度。此外，UST 缩短了达到最大强度的 SST 时间。在没有 UST 的情况下，强度在 520 °C 下 8 小时达到最大，而使用 UST 时，强度在 2 ~ 4 小时时达到最大。还讨论了 SST 时组成相的溶解。