(大连理工大学 材料科学与工程学院，大连 116024)
摘 要: 利用光学显微镜、电子探针分析、透射电子显微镜、X射线衍射仪及拉伸实验等技术研究Ni、Si元素对Cu-20Fe(质量分数，%)合金的组织及力学性能的影响。结果表明：添加Ni和Si元素导致Cu-20Fe合金中α-Fe枝晶发生明显的粗化行为。此外，由于合金元素的添加使得γ-Fe和富铜析出相之间的界面能减小，从而使得富铜析出相的形貌发生显著变化，即由近球形转变为立方形。相比于未添加合金元素的二元合金而言，添加合金元素之后，多组元合金的强度和塑性均得到提高。多组元合金的屈服强度和伸长率分别为304 MPa和16%。通过理论计算和实验验证，确定合金的主要强化机制为固溶强化和析出强化。
关键字: 显微组织；形貌转变；界面能；强化机制
（School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China）
Abstract:The effects of Ni and Si elements on the microstructure and mechanical properties of Cu-20Fe (mass fraction, %) alloy were studied by optical microscope, electron probe analysis, transmission electron microscope, X-ray diffractometer and tensile experiment. The results show that the addition of Ni and Si elements leads to obvious coarsening behavior of the α-Fe dendrites in the Cu-20Fe alloy. In addition, due to the addition of alloying elements, the interface energy between γ-Fe and the copper-rich precipitation phase is reduced, so that the morphology of the copper-rich precipitation phase has undergone a significant change, that is, it changes from a nearly spherical shape to a cube. Compared with the binary alloy without adding alloying elements, the strength and plasticity of the multi-component alloy are improved after the addition of alloying elements. The yield strength and elongation of the multi-component alloy are 304MPa and 16%, respectively. Through theoretical calculation and experimental verification, it is determined that the main strengthening mechanism of the alloy is solid solution strengthening and precipitation strengthening.
Key words: microstructure; morphology transformation; interface energy; strengthening mechanism
