Li Jiang, Huang Guojie, Mi Xujun, Peng Lijun, Xie Haofeng, Kang Yonglin
State Key laboratory of Nonferrous Metals and Processes, GRIMAT Engineering Institute Co., Ltd., Beijing 101417, China.
School of Materials Science and Engineering, University of Science & Technology Beijing, Beijing 100083, China.
Materials (Basel). 2019 Sep 4;12(18):2855. doi: 10.3390/ma12182855.
The properties and microstructural evolution of quaternary Cu-Ni-Co-Si alloys with different Ni/Co mass ratios are investigated systematically. These alloys exhibit higher mechanical properties when the Ni/Co mass ratio is 1.12-1.95 (NC-4-NC-5) and show excellent electrical conductivity when the Ni/Co mass ratio is 0.05-0.5 (NC-1-NC-3). With an increase in the Ni/Co ratio, the dimension of precipitated phase continues to increase and the grain size also visibly grows and coarsens. At the same time, the precipitation process of the NC-5 alloy is the most adequate, resulting in the highest mechanical properties. In addition, the precipitated phase in the alloys was confirmed to be the (Ni, Co)Si composite phase. The number of NiSi phases in the precipitated phase gradually increased, and the Ni atoms exhibited the strongest co-segregation alongside the increasing Ni/Co ratio. Compared with the alloy without a Co element, the addition of Co helped refine the grain size and accelerate the precipitation of the particle phase and purify solute atoms in the matrix, thereby simultaneously improving mechanical properties and conductivity. The present work provides a new method for the development of multicomponent Cu-Ni-Si-Co-X alloys with outstanding comprehensive performance.
系统研究了不同镍钴质量比的四元Cu-Ni-Co-Si合金的性能及微观结构演变。当镍钴质量比为1.12 - 1.95（NC-4 - NC-5）时，这些合金表现出较高的力学性能；当镍钴质量比为0.05 - 0.5（NC-1 - NC-3）时，合金具有优异的电导率。随着镍钴比的增加，析出相尺寸持续增大，晶粒尺寸也明显长大和粗化。同时，NC-5合金的析出过程最为充分，导致其力学性能最高。此外，合金中的析出相被确认为（Ni, Co）Si复合相。析出相中NiSi相的数量逐渐增加，并且随着镍钴比的增加，Ni原子表现出最强的共偏聚现象。与不含Co元素的合金相比，Co的加入有助于细化晶粒尺寸、加速颗粒相的析出并净化基体中的溶质原子，从而同时提高力学性能和电导率。本工作为开发具有优异综合性能的多组分Cu-Ni-Si-Co-X合金提供了一种新方法。
