In this paper, the concept, microstructure and properties of the Ni-Cr-Ta-Al-C complex phase alloy are presented. The alloy was designed to work at elevated temperatures, in a chemically aggressive environment and under harsh wear conditions. The alloy was examined in an as-cast state and after heat treatment using a number of complementary techniques such as: scanning electron microscopy, 3D reconstruction by means of focused ion beam-scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nanoindentation, dilatometry, hardness measurements and in-situ tensile tests at elevated temperatures. The microstructure of the alloy is comprised of a dendritic chromium-rich nickel-based matrix, which is strengthened by spheroidal precipitations of the γ’ Ni₃(AlTa) phase as well as Chinese script-like TaC and Cr₇C₃ carbides. Analysing hardness and microstructural changes of the alloy after solution treatment and after aging in different conditions allows to optimise the alloy's heat treatment procedure. It was found that the alloy achieved the highest hardness values after aging at 800 °C, which is related with the evolution of the γ’ phase. Additionally, it was discovered that primary carbides are stable up to at least 1150 °C, which is promising from the viewpoint of working at elevated temperatures and under harsh wear conditions. The herein reported results show that the combination of eutectic carbides and ordered γ’ phase for strengthening and, possibly, improving wear resistance of the alloy is effective up to at least 850 °C.

介绍了Ni-Cr-Ta-Al-C复合相合金的概念，组织和性能。该合金设计用于在高温，化学侵蚀性环境和恶劣磨损条件下工作。在铸造状态下和热处理后，使用多种互补技术检查合金，例如：扫描电子显微镜，借助聚焦离子束扫描电子显微镜进行3D重建，透射电子显微镜，X射线衍射，纳米压痕，膨胀计，硬度测量和高温下的原位拉伸测试。合金的微观结构由树枝状富铬的镍基基质组成，通过γ'Ni _3的球状沉淀得到强化（AlTa）相以及类似中文的TaC和Cr ₇ C ₃碳化物。分析固溶处理后以及在不同条件下进行时效处理后合金的硬度和显微组织变化，可以优化合金的热处理程序。发现该合金在800°C时效后达到了最高的硬度值，这与γ'相的演变有关。此外，还发现一次碳化物在至少1150°C的温度下都稳定，从高温和苛刻的磨损条件下工作的观点来看，这是有希望的。本文报道的结果表明，共晶碳化物和有序γ′相的组合在至少850℃以下有效并有效地改善了合金的耐磨性。