Li Huimin, Jin Junjun, Zhang Zhiyi, Yu Jinpeng, Sun Hairong, Sun Songling, Tang Weijie, Gou Guoqing
Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China.
CRRC Qingdao Sifang Co., Ltd., Qingdao 266111, China.
Materials (Basel). 2025 Mar 13;18(6):1267. doi: 10.3390/ma18061267.
High-entropy alloys (HEAs) have garnered significant global interest due to their outstanding properties. This study investigates the structural stability and mechanical properties of FeCoCrNiMo (x = 0, 0.4, 0.5, 0.8, 1.3) HEAs using a first-principles approach coupled with the special quasi-random structure (SQS) method. Of the alloys examined, all except FeCoCrNiMo were found to be thermodynamically and dynamically stable. Elasticity calculations revealed that molybdenum improves the ductility and anisotropy of the alloys, though with a slight decrease in strength and stiffness, as confirmed by electronic structure analysis. Defect-free FeCoCrNiMo HEAs coatings were then prepared using laser cladding and characterized for their microstructure and hardness. The coating exhibited a transition from columnar crystals at the bottom to equiaxed crystals at the surface, forming a honeycomb-like structure. Inside the crystal cells, high-density dislocations and σ-phase were observed. Elasticity calculations of the σ-phase confirmed its high hardness, low ductility, and classification as a brittle, hard phase.
高熵合金（HEAs）因其优异的性能而在全球引起了广泛关注。本研究采用第一性原理方法结合特殊准随机结构（SQS）方法，研究了FeCoCrNiMo（x = 0, 0.4, 0.5, 0.8, 1.3）高熵合金的结构稳定性和力学性能。在所研究的合金中，除FeCoCrNiMo外，其他合金均被发现具有热力学和动力学稳定性。弹性计算表明，钼提高了合金的延展性和各向异性，不过强度和刚度略有下降，电子结构分析证实了这一点。然后使用激光熔覆制备了无缺陷的FeCoCrNiMo高熵合金涂层，并对其微观结构和硬度进行了表征。涂层呈现出从底部的柱状晶体到表面的等轴晶体的转变，形成蜂窝状结构。在晶胞内部，观察到高密度位错和σ相。对σ相的弹性计算证实了其高硬度、低延展性，并将其归类为脆性硬相。
