摘要
The segregation of Sn and discontinuous precipitation at grain boundaries are detrimental to the strength,ductility,and machinability of the Cu−Ni−Sn alloy.A strategy to solve the above problems is multi-component composition design by introducing strong enthalpic interaction element.In this work,a series of Cu_(80)Ni_(15)Sn_(5−x)Ti_(x)(at.%)alloys were designed by cluster-plus-glue-atom model,and the effects of Ti content on the microstructure and properties of the alloys were systematically investigated using TEM and other analysis methods.The results demonstrate that Ti can effectively inhibit the segregation and discontinuous precipitation while promoting continuous precipitation to improve the high-temperature stability of the alloys.As the Ti content increases,the distribution of Ti changes from uniform distribution to predominant precipitation.The hardness and conductivity of the alloy exceed those of the C72900(Cu−15Ni−8Sn(wt.%))commercial alloy and the Cu_(80)Ni_(15)Sn_(5)(at.%)reference alloy when Ti is in the solution state.
Sn偏析和晶界处不连续析出会恶化Cu−Ni−Sn合金的强度、塑性和可加工性。为了解决上述问题,可通过引入强焓相互作用元素对合金进行多组元化成分设计。本文采用团簇加连接原子模型设计一系列Cu_(80)Ni_(15)Sn_(5−x)Ti_(x)(摩尔分数,%)合金,然后利用TEM等分析方法系统研究了Ti含量对合金显微组织及性能的影响。结果表明,Ti能有效抑制偏析和不连续析出,同时促进连续析出,从而提高合金的高温稳定性。随着Ti含量的增加,Ti在合金中的分布方式从均匀分布转变为以析出为主。当Ti处于固溶状态时,合金的硬度和电导率均超过C72900(Cu−15Ni−8Sn(质量分数,%))工业合金和Cu_(80)Ni_(15)Sn_(5)(摩尔分数,%)参比合金。
基金
support from the National Natural Science Foundation of China(No.52071052).
