The Ni-rich part of the ternary system Al–Ge–Ni (xNi > 50 at.%) was investigated by means of optical microscopy, powder X-ray diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM). The two isothermal sections at 550 °C and 700 °C were determined. Within these two sections a new ternary phase, designated as τ4, AlyGe9−yNi13±x (hP66, Ga3Ge6Ni13-type) was detected and investigated by single crystal X-ray diffraction. Another ternary low temperature phase, τ5, was found only in the isothermal section at 550 °C around the composition AlGeNi4. This compound was found to crystallise in the Co2Si type structure (oP12, Pnma). The structure was identified by Rietveld refinement of powder data. The NiAs type (B8) phase based on binary Ge3Ni5 revealed an extended solid solubility of Al and the two isotypic compounds AlNi3 and GeNi3 form a complete solid solution. Based on DTA results, six vertical sections at 55, 60, 70, 75 and 80 at.% Ni and at a constant Al:Ni ratio of 1:3 were constructed. Furthermore, the liquidus surface projection and the reaction scheme (Scheil diagram) were completed by combining our results with previous results from the Ni-poor part of the phase diagram. Six invariant ternary reactions were identified in the Ni-rich part of the system.

中文翻译：

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Al-Ge-Ni 相图的富镍部分

通过光学显微镜、粉末 X 射线衍射 (XRD)、差热分析 (DTA) 和扫描电子显微镜研究了三元系统 Al-Ge-Ni (xNi > 50 at.%) 的富镍部分。扫描电镜）。确定了 550 °C 和 700 °C 的两个等温段。在这两个部分中，通过单晶 X 射线衍射检测并研究了一个新的三元相，称为 τ4，AlyGe9-yNi13±x（hP66，Ga3Ge6Ni13 型）。另一个三元低温相 τ5 仅在成分 AlGeNi4 周围 550 °C 的等温部分中发现。发现该化合物以 Co2Si 型结构（oP12，Pnma）结晶。通过粉末数据的 Rietveld 精修确定结构。基于二元 Ge3Ni5 的 NiAs 型 (B8) 相揭示了 Al 的扩展固溶度，并且两种同型化合物 AlNi3 和 GeNi3 形成完整的固溶体。根据 DTA 结果，在 55、60、70、75 和 80 at.% Ni 和 1:3 的恒定 Al:Ni 比率下构建了六个垂直截面。此外，液相线表面投影和反应方案（Scheil 图）是通过将我们的结果与之前的相图贫镍部分的结果相结合而完成的。在系统的富镍部分确定了六个不变的三元反应。液相线表面投影和反应方案（Scheil 图）是通过将我们的结果与之前相图中贫 Ni 部分的结果相结合而完成的。在系统的富镍部分确定了六个不变的三元反应。液相线表面投影和反应方案（Scheil 图）是通过将我们的结果与之前相图中贫 Ni 部分的结果相结合而完成的。在系统的富镍部分确定了六个不变的三元反应。