【摘要】 为开发适于在防护耐冲等极端环境服役的结构材料，本研究通过开展不同Si含量的CoCr_0.4NiSi_x（x=0,0.1,0.2,0.3,0.4,0.5，原子比）中熵合金的室温准静态拉伸及压缩力学试验，研究Si含量变化对室温准静态力学性能的影响规律。研究表明，随Si含量的增加，合金屈服强度及抗拉强度均显著增加，Si_0.3合金综合力学性能最佳。各Si含量合金室温准静态拉伸样品的XRD、SEM和EBSD结构与组织表征表明，室温准静态拉伸变形后，仍以FCC为基体相，Si_0.2开始出现HCP及四方结构相，随Si含量的增加，第二相含量增多，平均晶粒尺寸减小，合金呈现由韧转脆的断裂特征。Si的添加增强了位错与第二相的交互作用，显著增加了该体系合金的屈服强度和抗拉强度。更多还原

【Abstract】 To develop structural materials suitable for extreme environments such as protection and impact resistance,quasi-static tensile and compressive tests were conducted on CoCr_0.4NiSi_x（x=0,0.1,0.2,0.3,0.4,0.5,atomic ratio） alloys with varying silicon contents at room temperature.The influence of silicon content on the quasistatic mechanical properties at room temperature was investigated.The results demonstrated a significant increase in the yield strength and ultimate tensile strength of the alloys with increasing Si addition.Notably,the Si_0.3 alloy exhibited superior comprehensive mechanical properties compared to other components.The X-ray diffraction （XRD）,scanning electron microscopy （SEM）,and electron backscatter diffraction （EBSD）analyses of the quasi-static tensile samples of the alloys with varying Si content at room temperature reveal that the face-centered cubic （FCC） phase remains the dominant matrix after deformation.In the Si_0.2 alloy,hexagonal close-packed （HCP） and tetragonal phases begin to appear.As the Si content increases,the volume fraction of secondary phases rises,the average grain size diminishes,and the fracture mode shifts from ductile to brittle.The incorporation of Si enhances interactions between dislocations and the second phases,leading to a significant increase in both yield strength and ultimate tensile strength of the alloy.更多还原