合金化元素对W-Cu体系多类界面特征影响的第一性原理计算  

First-Principles Calculation on the Influence of Alloying Elements on Interfacial Features of W-Cu System

作　　者：盖逸冰 唐法威 侯超[1] 吕皓 宋晓艳[1] GAI Yibing;TANG Fawei;HOU Chao;LU Hao;SONG Xiaoyan(Key Laboratory of Advanced Functional Materials,Education Ministry of China,College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学材料科学与工程学院新型功能材料教育部重点实验室,北京100124

出　　处：《金属学报》2020年第7期1036-1046,共11页Acta Metallurgica Sinica

基　　金：国家重点研发计划项目No.2018YFB0703902;国家自然科学基金重点项目No.51631002;国家杰出青年科学基金项目No.51425101。

摘　　要：基于第一性原理界面模型对W-Cu复合材料体系中W/Cu相界、W晶界和Cu晶界的溶质偏聚行为进行了系列计算分析,定量化研究了W-Cu体系中多类界面的键合特征和Sc、Ti、Y、In等多种合金化元素的界面偏聚特点。结合W-Cu体系的偏聚能和电子结构计算,揭示了W-Cu体系中同种合金化元素在晶界偏聚和相界偏聚过程中可能存在的显著差异及其微观机理。通过W-Y和W-Sc体系中合金化元素添加结果的对比分析,阐述了强偏聚元素与界面稳定性之间的关联。进一步,结合晶界偏聚能、相界偏聚能、铜基固溶体形成能等计算,提出了W-Cu复合材料体系筛选溶质元素的基本判据,从原子尺度上为研究多相复合体系的合金化元素优选策略提供了普适性分析方法,同时为高性能W-Cu基复合材料的研发提供了新的设计思路。The W-Cu alloy has been widely applied in metallurgy,electronics,military and other fields because of its good arc-resistance,anti-welding,heat and electricity conducting etc.In the recent years,attention to the immiscible W-Cu alloy has been shifted to the problem of stabilizing the W/Cu interface by alloying.However,there are still research lacks of the mechanisms of diffusion,segregation of alloying elements in this alloy.It,obviously,will limit the further optimizing design for the W-Cu alloy.This work is focused on the first-principle study of the electronic structure of W/Cu interfaces.Calculations showed that the same alloying elements in W-Cu system may have significant differences in grain boundary segregation and interface segregation behavior,and related micromechanism was revealed.It was demonstrated that the relationship of the segregation energies of Sc,Ti,Y and In into W/Cu interfaces and grain boundaries of pure W and Cu were related to their stability.The correlation between segregation energy and interface stability was also disclosed by the first-principle interface calculation for W-Sc and W-Y systems.Further,combined with the solute segregation calculations for the W/Cu interfaces,W grain boundaries,Cu grain boundaries and the formation energy for the Cu solid solution,the criterion for solute optimizing selection for the W-Cu system was proposed.According to which,Y was selected as the candidate alloying element to stabilize the W/Cu interface.This work proposed a more universal method for the optimal alloying element selection and may provide a new design method for the development of high-performance W-Cu alloy.

关 键 词：第一性原理 W-CU复合材料 溶质偏聚 界面特征 

分 类 号：TG131[一般工业技术—材料科学与工程]