In this work, we investigate low-temperature sintering behavior of the 90W-7Ni-3Fe alloy by introducing Sn. The 90W-7Ni-3Fe alloy with different Sn contents (0, 0.5, 1.0 and 1.5 wt.%) was fabricated via vacuum sintering at 1300 °C for 90 min. When 1 wt.% Sn was added, the liquidus temperature of the 90W-7Ni-3Fe alloy decreased from 1477 to 1265 °C, resulting in rapid densification (relative density increased from 77.77 to 98.59%) and an homogeneous liquid-phase sintered microstructure. Electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) observations revealed that, apart from W and the γ-(Ni, Fe) phase, a new Ni₃Sn₂ phase appeared in the matrix phase. Furthermore, we discuss in detail the formation of the Ni₃Sn₂ phase based on element selection theory, which can be associated with the larger atomic radius of Sn and with the negative enthalpy of mixing Sn and Ni. Excessive Sn content (1.5 wt.%) led to the increase in Ni₃Sn₂ phase, and this deteriorated the relative density and tensile strength of the alloy. The 90W-7Ni-3Fe alloy with the addition of 1 wt.% Sn exhibited a maximum tensile strength value (710 MPa), which was much higher than that of the 90W-7Ni-3Fe alloy that was obtained at 1300 °C. Our findings shed light on further research directions and developed a 90W-6.3Ni-2.1Fe-1Sn alloy for low-temperature sintering.

在这项工作中，我们通过引入Sn来研究90W-7Ni-3Fe合金的低温烧结行为。通过在1300℃下真空烧结90分钟来制造具有不同Sn含量（0、0.5、1.0和1.5重量％）的90W-7Ni-3Fe合金。当添加1 wt。％的Sn时，90W-7Ni-3Fe合金的液相线温度从1477降低到1265°C，导致快速致密化（相对密度从77.77增加到98.59％）和均相液相烧结显微组织。电子探针显微分析（EPMA）和透射电子显微镜（TEM）观察表明，除了W和γ-（Ni，Fe）相之外，基质相中还出现了新的Ni ₃ Sn ₂相。此外，我们详细讨论了Ni ₃的形成基于元素选择理论的Sn ₂相，这可能与Sn的较大原子半径以及Sn和Ni混合的负焓有关。Sn含量过多（1.5重量％）导致Ni ₃ Sn ₂相的增加，这使合金的相对密度和拉伸强度变差。添加了1 wt。％Sn的90W-7Ni-3Fe合金具有最大拉伸强度值（710 MPa），远高于在1300°C下获得的90W-7Ni-3Fe合金的最大拉伸强度值。我们的发现为进一步的研究方向指明了方向，并开发出一种用于低温烧结的90W-6.3Ni-2.1Fe-1Sn合金。