Chang Hui, Wang Shengfang, Mao Zhouzhu, Zhang Tuanwei, Li Zhiqiang, Wang Zhihua
Institute of Applied Mechanics, College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
Shanxi Key Laboratory of Material Strength and Structural Impact, Taiyuan University of Technology, Taiyuan 030024, China.
Materials (Basel). 2024 Jun 13;17(12):2893. doi: 10.3390/ma17122893.
The effects of Si addition on the microstructures and properties of CoCrNi medium-entropy alloy (MEA) were systematically investigated. The CrCoNiSi MEA possesses a single face-centered cubic (FCC) phase when x is less than 0.3 and promotes solution strengthening, while the crystal structure shows a transition to the FCC+σ phase structure when x = 0.4 and the volume fraction of the σ phase increases with a microstructure evolution as the Si content increases. The Orowan mechanism from σ precipitation effectively enhances the strength, hardness, and stain hardening of CrCoNiSi MEA, which also exhibits superior hardness at high temperatures. Furthermore, a large amount of σ phase decreases the wear resistance because of the transformation of the main wear mechanism from abrasion wear for σ-free CrCoNiSi MEA to adhesion wear for σ-contained CrCoNiSi MEA. This work contributes to the understanding of the effect of Si addition on FCC structured alloys and provides guidance for the development of novel Si-doped alloys.
系统研究了添加Si对CoCrNi中熵合金（MEA）微观结构和性能的影响。当x小于0.3时，CrCoNiSi MEA具有单一的面心立方（FCC）相并促进固溶强化，而当x = 0.4时，晶体结构转变为FCC+σ相结构，并且随着Si含量的增加，σ相的体积分数随着微观结构的演变而增加。σ相析出的奥罗万机制有效地提高了CrCoNiSi MEA的强度、硬度和加工硬化能力，其在高温下也表现出优异的硬度。此外，大量的σ相降低了耐磨性，这是因为主要磨损机制从不含σ相的CrCoNiSi MEA的磨粒磨损转变为含σ相的CrCoNiSi MEA的粘着磨损。这项工作有助于理解添加Si对FCC结构合金的影响，并为新型Si掺杂合金的开发提供指导。
