摘要
Abstract
Based on the Cu-Sn-Bi supersaturated solid solution powders prepared by mechanical alloying,this study systematically investigates the sintering process,phase precipitation behavior,microstructural evolution,and mechanical properties.Through comparative experiments with varying Bi and Sn contents,the regulatory effect of Bi on the microstructure and the role of Sn solid-solution strengthening are clarified.The results show that after 40 h of ball milling,the Cu-10%Sn-5%Bi powder forms a Cu(Sn,Bi)supersaturated solid solution.During sintering,Sn remains in a solid-solution state,while Bi precipitates from the supersaturated solid solution at about 400℃,forming a finely dispersed free Bi phase.The optimal sintering temperature is 750℃.With increasing Bi content,the microstructure evolves as follows:at 3%Bi,the Bi phase is finely and sparsely dispersed;at 5%Bi,it distributes uniformly as fine particles;at 7%Bi,it becomes locally interconnected and splits the matrix.After sintering at 750℃,the Cu-10%Sn-5%Bi alloy achieves a relative density of 92.8%,a hardness of 116 HV,and a tensile strength of 164.4 MPa.Sn content comparison experiments show that the higher Sn alloy exhibits a lower friction coefficient and a smoother worn surface.关键词
机械合金化/Cu-Sn-Bi/过饱和固溶体/烧结行为/力学性能/摩擦学性能Key words
mechanical alloying/Cu-Sn-Bi/supersaturated solid solution/sintering behavior/mechanical properties/tribological performance分类
通用工业技术
