An investigation of lanthanum oxide (La2O3) addition to tungsten heavy alloy (WHA) with a ternary composition of W–7Ni–3Fe was reported in this study. The mixed powders were sintered using spark plasma sintering (SPS) technique. La2O3 was added in increments of 0.25 wt%, 0.50 wt%, 0.75 wt% and 1.00 wt% to WHA, respectively. The sintered samples were characterized for microstructural evolution and mechanical properties. The influences of La2O3 addition on density, grain size, hardness, ultimate tensile strength (UTS) and ductility on W–7Ni–3Fe system were discussed in this study. The highest relative sintered density of 87.95% was obtained for 0.25 wt% La2O3 addition to W–7Ni–3Fe. The lowest grain size of 7.89 μm was observed for 1.00 wt% La2O3 addition. Similarly, the highest hardness and UTS of HV 533 and 1110 MPa, respectively, were also obtained for the same composition. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) of the samples revealed homogenous distribution of La2O3 in the alloy matrix. Fractography of the sintered alloy samples revealed W–W intergranular fracture.

中文翻译：

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放电等离子烧结La2O3弥散强化W-Ni-Fe合金的组织和力学性能

本研究报告了将氧化镧 (La2O3) 添加到具有 W-7Ni-3Fe 三元组成的钨重合金 (WHA) 中的研究。使用放电等离子烧结（SPS）技术烧结混合粉末。La2O3 分别以 0.25 wt%、0.50 wt%、0.75 wt% 和 1.00 wt% 的增量添加到 WHA。对烧结样品的微观结构演变和机械性能进行表征。本研究讨论了添加 La2O3 对 W-7Ni-3Fe 系统的密度、晶粒尺寸、硬度、极限抗拉强度 (UTS) 和延展性的影响。在 W-7Ni-3Fe 中添加 0.25 wt% La2O3 获得了 87.95% 的最高相对烧结密度。添加 1.00 wt% La2O3 时观察到的最低晶粒尺寸为 7.89 μm。同样，最高硬度和 UTS 分别为 HV 533 和 1110 MPa，也获得了相同的组合物。样品的扫描电子显微镜 (SEM) 和能量色散谱 (EDS) 显示 La2O3 在合金基体中分布均匀。烧结合金样品的断口分析显示 W-W 晶间断裂。