Nb含量对机械合金化Cu-Nb合金组织与性能的影响  

Effect of Nb content on microstructure and properties of Cu-Nb alloys prepared by mechanical alloying

作　　者：雷若姗 汪明朴[2] LEI Ruoshan;WANG Mingpu(College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, China;School of Materials Science and Engineering, Central South University, Changsha 410083, China)

机构地区：[1]中国计量大学材料科学与工程学院,杭州310018 [2]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2017年第5期656-661,共6页Materials Science and Engineering of Powder Metallurgy

基　　金：国家自然科学基金资助项目(51401197)

摘　　要：在金属铜粉中分别加入1.5%和6%的Nb粉(质量分数),通过机械合金化和800℃/2 h/30 MPa条件下真空热压,制备Cu-1.5%Nb和Cu-6%Nb合金,采用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)以及电导率与硬度测试,研究Nb含量对合金微观组织结构与性能的影响。结果表明,通过机械合金化得到的Cu-1.5%Nb和Cu-6%Nb复合粉末,Cu相平均晶粒尺寸分别约为17和13 nm。Nb含量增加有助于抑制Cu晶粒长大,热压Cu-6%Nb合金中Cu相的平均晶粒尺寸保持纳米级(65 nm),而Cu-1.5%Nb合金的Cu晶粒平均尺寸为亚微米级,约为110 nm。热压过程中脱溶析出的Nb颗粒尺寸分布为双模态,既有尺寸大于100 nm的粗大Nb粒子,也有尺寸小于10 nm的纳米Nb粒子。与Cu-1.5%Nb合金相比,Cu-6%Nb合金的显微硬度(HV)提高了112,但电导率降低约7.54×10~6 S/m。细晶强化和弥散强化是Cu-Nb合金的主要强化机制。Cu-1.5%Nb and Cu-6%Nb alloys were prepared by mechanical alloying and subsequent vacuum hot-pressing(800℃/2h/30MPa)using Cu and Nb powders as raw materials.The effect of Nb content on the microstructure and properties of the alloys were studied by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),electrical conductivity and microhardness tests.The results show that,the average grain sizes of Cu phase in Cu-1.5%Nb and Cu-6%Nb composite powders fabricated by mechanical alloying are17and13nm,respectively,the resistance of grain growth is enhanced with increasing Nb content.After vacuum hot-pressing sintering at800℃for2h,the average Cu grain sizes are about65and110nm for Cu-6%Nb and Cu-1.5%Nb alloys,respectively.The size of precipitated Nb exhibits a bimodal distribution after consolidation.There are a number of Nb particles with sizes less than10nm,while a few large Nb particle sizes are above100nm.Compared with Cu-1.5%Nb alloy,the microhardness of Cu-6%Nb alloy increases about112HV;however,the electrical conductivity decreases about7.54×106S/m.The strengthening mechanism of Cu-Nb alloys is mainly related with the fine grain strengthening and dispersion strengthening.

关 键 词：机械合金化 热压 铜合金 微观结构 高强高导 

分 类 号：TG146.1[一般工业技术—材料科学与工程]