Abstract Generally, μ phase preferentially precipitates at the place where the refractory elements segregate. However, in this study, the μ phase preferentially formed in the interdendritic regions of Co-Ni-Al-W-based superalloys during solution treatment, while the refractory elements W and Cr segregate to the dendritic cores. The microstructure evolution of the alloy during solution treatment was investigated. It showed that three different mechanisms caused this abnormal precipitation in the interdendritic regions, including primary carbides degeneration, further degeneration of the secondary carbides formed by the Laves phase decomposition, and direct precipitation from the interdendritic regions induced by the Laves phase decomposition.

中文翻译：

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γ'强化Co-Ni-Al-W基高温合金固溶处理过程中μ相的异常析出

摘要 通常，μ相优先在难熔元素偏析的地方析出。然而，在本研究中，固溶处理过程中，在 Co-Ni-Al-W 基高温合金的枝晶间区域优先形成 μ 相，而难熔元素 W 和 Cr 偏析到枝晶核。研究了合金在固溶处理过程中的微观结构演变。结果表明，三种不同的机制导致了枝晶间区域的异常析出，包括一次碳化物变质、Laves 相分解形成的二次碳化物的进一步变质以及 Laves 相分解引起的枝晶间区域的直接析出。