细化处理对铸造铋黄铜组织和切削性能的影响  

Effect of Refinement Treatment on the Microstructure and Cutting Properties of Cast Bismuth Brasses

作　　者：谢康 任卡卢比 代丽鑫 肖柱[1,2] 贾延琳[1,2] XIE Kang;REN Kalubi;DAI Lixin;XIAO Zhu;JIA Yanlin(School of Materials Science and Engineering,Central South University,Changsha 410083,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《铸造技术》2024年第1期50-55,共6页Foundry Technology

基　　金：宁波市科技创新2025重大专项(2022Z104);湖南创新型省份建设专项(2021GK2016)。

摘　　要：无铅易切削铋黄铜具有环保、力学性能良好、导热良好的特点,是5G光学模块垫片的首选材料。晶粒组织粗大和铋相分布不均匀会导致切削一致性较差,染黑后出现毛刺加深、着色不均等问题。B、Ti、Zr是工业上常用的细化变质剂,可以细化晶粒和组织,从而提高铋黄铜的切削性能。本文采用铋黄铜(成分为58.3%Cu、40.85%Zn、0.07%P、0.7%Bi、0.08%Sn),分别添加0.1%(质量分数)的B、Ti、Zr,采用宏观、微观、SEM对晶粒、组织、铋相粒子进行比较分析。结果表明,添加0.1%(质量分数)的B、Ti、Zr对铸造铋黄铜晶粒尺寸都有较为显著的细化效果。无添加变质剂样品无等轴晶,而0.1%(质量分数)的B、Ti、Zr等轴晶尺寸为1.43、0.95、0.71 mm,故添加Zr的细化效果优于Ti,Ti的细化效果略优于B。同时B、Ti、Zr的添加对于晶内α+β双相组织也有细化效果,Zr的细化效果优于Ti,Ti的细化效果略微优于B。且加入B、Ti、Zr有助于消除薄膜状分布的趋势,改善铋相的分布。其中B的效果优于Ti和Zr。而4种样品切削性能排序为:B>Zr>Ti>无添加变质剂,影响切削性能的因素包括铋相和β相数密度。Lead-free easy-cutting bismuth brass,which is the preferred material for 5G optical module gaskets,has the characteristics of environmental friendliness,good mechanical properties,good thermal conductivity and easy cutting.A coarse grain size and uneven distribution of the bismuth phase lead to poor cutting consistency,deep burrs and uneven colouration after dyeing black,etc.B,Ti,and Zr are commonly used refining modifiers in industry and can refine grains and microstructures,thus improving the cutting performance of bismuth brass.In this paper,a bismuth brass with a composition of 58.3wt.%Cu,40.85wt.%Zn,0.07wt.%P,0.7wt.%Bi,and 0.08wt.%Sn was taken as the research subject,from which 0.1wt.%B,Ti or Zr was added.Macroscopic metallography,microscopic metallography and SEM were used to analyse the grains,microstructure and bismuth phase particles.The results show that the addition of 0.1wt.%B,Ti,or Zr has a significant refining effect on the grain size of the cast bismuth brass.The modifier-free sample has no equiaxial crystal,while the samples with 0.1wt.%added B,Ti,or Zr have equiaxial crystal sizes of 1.43,0.95 and 0.71 mm,respectively.Therefore,the refining effect of adding Ti is slightly better than that of B but poorer than that of Zr.Moreover,the addition of B,Ti,and Zr also refines the intracrystallineα+βbiphasic structure,with the refining effect of Zr being better than that of Ti and that of Ti being slightly better than that of B.In addition,the addition of B,Ti and Zr helps to eliminate the tendency of the bismuth phase to form film and improve the distribution of the bismuth phase.Among them,the effect of B is better than that of Ti or Zr.The cutting performance of the four samples decreases in the order B>Zr>Ti>modifier-free,the influencing factors of which include the bismuth phase and beta phase number density.

关 键 词：铋黄铜 细化处理 显微组织 铋相粒子 切削性能 

分 类 号：TG146.11[一般工业技术—材料科学与工程]