Ru is a common addition to the Co-binder in WCCo hardmetals for advanced cutting tool applications. Internal Co-Co interfaces control many properties such as hot-hardness, toughness, and creep resistance. Hence, phase transformations determining the internal interface character can be harnessed to achieve superior properties. We investigate the γ (face-centred cubic) to α (hexagonally closed packed) martensitic phase transformation of a model Co-Ru binder alloy. We describe the crystallography of γ to α phase transformations and the resulting α/γ and α/α interface character distributions. The stabilisation of the γ-phase results in the formation of low energy (0 0 0 1) α/γ interphase boundary planes. Preferred formation of α/α intervariant and twin-related boundaries with symmetrical tilt configurations are also observed. We discuss how crystallographic constraints of the transformation promote the formation of grain boundary planes other than those of the lowest energy configurations.

中文翻译：

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关于 Co-Ru 合金中的面心立方到六面体的转变：变体选择和互变边界特征

Ru 是 WCCo 硬质合金中辅助粘合剂的常见添加物，适用于高级切削刀具应用。内部 Co-Co 界面控制着许多性能，例如热硬度、韧性和抗蠕变性。因此，可以利用决定内部界面特性的相变来实现优异的性能。我们研究了模型 Co-Ru 粘结剂合金的 γ（面心立方）到 α（六方密排）马氏体相变。我们描述了 γ 到 α 相变的晶体学以及由此产生的 α/γ 和 α/α 界面特征分布。 γ 相的稳定导致低能 (0 0 0 1) α/γ 相间界面的形成。还观察到具有对称倾斜配置的 α/α 互变和孪生相关边界的优选形成。我们讨论了转变的晶体学约束如何促进除了最低能量构型之外的晶界平面的形成。