引线框架用CuCrSnZnSi铜合金组织与性能

Microstructure and properties of CuCrSnZnSi copper alloy for lead frames

采用SEM、EBSD、XRD、TEM及力学、电学性能检测手段,研究了Cu-0.2Cr-0.252Sn-0.166Zn-0.014Si合金的微观组织结构与强化机制。结果表明,铸态Cu-0.2Cr-0.252Sn-0.166Zn-0.014Si合金经热轧+水冷、冷轧、时效、冷轧、退火处理后的抗拉强度、屈服强度、显微硬度、断后伸长率、导电率分别为483 MPa、452 MPa、178.0 HV_(0.2)、9%和69.6%IACS。退火处理后合金平均晶粒尺寸约为1.20μm,局部应变较高,晶粒错位角为17.15°,具有较强的择优取向,以Goss织构({110}<001>)和Copper织构({112}<11-1>)为主。Sn、Zn元素以固溶的形式弥散分布于基体中,Cr元素则以纳米相的形式分布于基体中,晶界强化是退火态Cu-0.2Cr-0.252Sn-0.166Zn-0.014Si合金的主要强化机制,Cr元素纳米析出强化与Sn、Zn元素固溶强化、位错强化相对较弱。

The microstructure and strengthening mechanism of Cu-0.2Cr-0.252Sn-0.166Zn-0.014Si alloy were studied using SEM,EBSD,XRD,TEM as well as mechanical and electrical performance testing methods.The results show that the tensile strength,yield strength,microhardness,elongation after fracture and conductivity of as-cast Cu-0.2Cr-0.252Sn-0.166Zn-0.014Si alloy after hot rolling+water cooling,cold rolling aging,cold rolling and annealing treatment are 483 MPa,452 MPa,178.0 HV0.2,9%and 69.6%IACS,respectively.The average grain size of the alloy after annealing treatment is about 1.20μm.The local strain is relatively high,with a grain dislocation angle of 17.15°and a strong preferred orientation,mainly characterized by Goss texture({110}<001>)and Copper texture({112}<11-1>).The elements Sn and Zn are dispersed in the matrix in a solid solution form,while the element Cr is distributed in the matrix in a nano phase form,the grain boundary strengthening is the main strengthening mechanism of annealed Cu-0.2Cr-0.252Sn0.166Zn-0.014Si alloy,with relatively weaker element Cr nanoprecipitation strengthening,elements Sn and Zn solid solution strengthening and dislocation strengthening.