In this work three complete isothermal sections of the Ni–Sn–Zn system at 700, 800 and 900 °C are presented. They were constructed based on experimental investigation of more than 60 alloy samples. Powder XRD, single crystal XRD, EPMA, and DTA measurements on selected samples were carried out. Two new ternary compounds, designated as τ2 (Ni5Sn4Zn) and τ3 (Ni7Sn9Zn5), were identified and their homogeneity ranges and crystal structures could be described. Whereas τ3 is only present at 700 °C, the τ2-phase was found at both 700 and 800 °C. No truly ternary compound could be found in the isothermal section at 900 °C. A seemingly ternary compound at 20 at% Sn in the Ni-rich part of Ni–Sn–Zn was found at 800 and 900 °C. Our XRD results, however, indicate that this phase is a ternary solid solution of Ni3Sn-HT from constituent binary Ni–Sn. It is stabilized to lower temperatures by additions of Zn. These new experimental results will provide valuable information to the thermodynamic description of alloy systems relevant for high-temperature lead-free soldering.

中文翻译：

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Ni-Sn-Zn 体系的高温相平衡：等温截面

在这项工作中，展示了 Ni-Sn-Zn 系统在 700、800 和 900 °C 下的三个完整等温截面。它们是基于对 60 多个合金样品的实验研究而构建的。对选定的样品进行了粉末 XRD、单晶 XRD、EPMA 和 DTA 测量。鉴定出两种新的三元化合物，命名为 τ2 (Ni5Sn4Zn) 和 τ3 (Ni7Sn9Zn5)，并且可以描述它们的均匀性范围和晶体结构。τ3 仅在 700 °C 下存在，而 τ2 相在 700 和 800 °C 下均存在。在 900 °C 的等温段中没有发现真正的三元化合物。在 800 和 900 °C 时，在 Ni-Sn-Zn 的富镍部分中发现了看似三元化合物，其锡含量为 20 at%。然而，我们的 XRD 结果表明，该相是由二元 Ni-Sn 组成的 Ni3Sn-HT 的三元固溶体。通过添加 Zn 可使其在较低温度下保持稳定。这些新的实验结果将为高温无铅焊接相关合金系统的热力学描述提供有价值的信息。