A novel tungsten heavy alloy (WHA), with composition 89 W-5.1Ni-3.4Cu-1.5Fe-1La₂O₃ (wt%) (Modified WHA) and the Ni/Cu ratio of 6/4, was sintered at 1400 °C for 1 h. The synergetic effects of La2O3 dispersion strengthening, which controls W particle growth, and Fe solid solution strengthening within the matrix, enhancing the compressive and bending strength of modified WHA. Microstructural analysis showed tungsten particle size and contiguity of 21 μm and 0.41, while mechanical testing revealed substantial improvements, with a hardness of 343 HV5, compressive strength of 2250 MPa, and bending strength of 1417 MPa. Fractography indicated failure modes involving WW and W-matrix de-cohesion, transgranular fractures, and dimpled fractures, attributed to the combined strengthening mechanisms. Transmission electron microscopy (TEM) analysis provided detailed insights into the sintered alloys, particularly revealing the locations of La2O3, WW, and W-matrix interfaces, as well as the distribution of precipitates within the matrix and tungsten. This study demonstrates that the tailored addition of La2O3 and Fe significantly enhances WHA properties, positioning this alloy as a robust candidate for high-strength applications.

中文翻译：

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液相烧结 La2O3 和 Fe 改性 W-Ni-Cu 重合金的微观组织和力学特性


一种新型钨重合金 （WHA），成分为 89 W-5.1Ni-3.4Cu-1.5Fe-1La₂O₃ （wt%） （改性 WHA），Ni/Cu 比为 6/4，在 1400 °C 下烧结 1 h。La2O3 分散体强化的协同效应，控制 W 颗粒生长，以及基体内的 Fe 固溶体强化，提高改性 WHA 的压缩和弯曲强度。微观结构分析显示钨的粒度和连续性分别为 21 μm 和 0.41，而机械测试显示钨的硬度有显著提高，硬度为 343 HV5，抗压强度为 2250 MPa，弯曲强度为 1417 MPa。断口图显示失效模式涉及 WW 和 W 基体去粘连、跨晶裂缝和凹陷裂缝，归因于联合加固机制。透射电子显微镜 （TEM） 分析提供了对烧结合金的详细见解，特别是揭示了 La2O3、WW 和 W 基体界面的位置，以及基体和钨内沉淀物的分布。这项研究表明，量身定制的 La2O3 和 Fe 的添加显着增强了 WHA 性能，使这种合金成为高强度应用的可靠候选者。