In the last decade, extensive research has been carried out on the microstructural behavior of high-entropy alloys (HEA), for which the in-situ formation of nanoparticles has been reported. However, studies of the incorporation of nanoparticles in HEA have been rarely reported. In this work, the addition of zinc oxide nanoparticles (ZnO NP) as reinforcement in a CoCrFeMoNi high-entropy alloy matrix, as well as the morphological, structural, and microstructural evolution of composites synthesized via powder metallurgy, were studied. Scanning electron microscopy and X-ray diffraction analysis were performed in order to study the microstructural and phase characterization of the composites. After sintering, it was found that the ZnO NP addition (0.5wt%, 1wt% and 2wt%) had a significant influence on the micro-structure and hardness of the CoCrFeMoNi high-entropy alloy. Stronger bonding among metal particles was promoted with the additions of ZnO NP. A reduction in porosity as a function of ZnO NP content was also observed. The microhardness results showed that the composite reached its highest reinforcement in bulk samples with 1wt% ZnO NP (HV 870), which represented a 20% improvement over the unrein-forced HEA matrix.

在过去的十年中，已经对高熵合金（HEA）的微观结构行为进行了广泛的研究，为此已经报道了纳米粒子的原位形成。然而，很少有关于在HEA中掺入纳米颗粒的研究。在这项工作中，研究了在CoCrFeMoNi高熵合金基体中添加氧化锌纳米颗粒（ZnO NP）作为增强材料，以及通过粉末冶金合成的复合材料的形貌，结构和微观结构演变。为了研究复合材料的微观结构和相表征，进行了扫描电子显微镜和X射线衍射分析。烧结后发现添加了ZnO NP（0.5wt％，1wt％和2wt％对CoCrFeMoNi高熵合金的显微组织和硬度有显着影响。ZnO NP的加入促进了金属颗粒之间更牢固的键合。还观察到作为ZnO NP含量的函数的孔隙率降低。显微硬度结果表明，复合材料在具有1wt％的ZnO NP（HV 870）的散装样品中达到了最高的增强，比未增强的HEA基质提高了20％。