A six-component system of CoNiCuCrx high-entropy alloys with different contents of chromium (where x = 0, 0.5, 1.0, 2.0, and 3.0 mole) is obtained by the method of argon-arc melting in a МІFІ-9 study. By the methods of X-ray diffraction analysis, scanning-electron microscopy, and indentation, we investigate the influence of chromium on the crystalline structure, microstructure, and hardness of these alloys in the as-cast state. In their structure, depending on the chromium content, we detect a mixture of the following phase components: two face-centered cubes + a body-centered cube + an intermetallic σ-phase (FCC1 + FCC2 + BCC + σ). It is also established that, as the chromium content increases, we observe the formation of the bcc structure and the σ-phase, which is the predominant factor of hardening of the alloy.

中文翻译：

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铬对MnFeCoNiCu高熵合金相组成和硬化特性的影响

在 МІFІ-9 研究中，通过氩弧熔化法获得了具有不同铬含量（其中 x = 0、0.5、1.0、2.0 和 3.0 摩尔）的 CoNiCuCrx 高熵合金的六组分系统。通过 X 射线衍射分析、扫描电子显微镜和压痕等方法，我们研究了铬对铸态合金的晶体结构、显微组织和硬度的影响。在它们的结构中，根据铬含量，我们检测到以下相成分的混合物：两个面心立方体 + 一个体心立方体 + 一个金属间 σ 相（FCC1 + FCC2 + BCC + σ）。还确定，随着铬含量的增加，我们观察到 bcc 结构和 σ 相的形成，这是合金硬化的主要因素。