一种高强高导稀土铜镍硅铬合金的制备方法,属于引线框架材料领域。合金成分为：2.5-3.5％Ni，2.0-3.0％Si，1.5-2.0％Cr，0.1-1.0％Ce，0.1-0.6％Pr和0.1–0.6％Nb，其余为Cu和不可避免的杂质。先将原料粉末置于高能球磨机中,使其混合均匀和进行预反应,然后加入熔有纯铜的真空熔炼炉中电磁搅拌熔炼。浇铸、锻造成方坯,再经高温固溶处理,然后进行多道次冷轧、退火处理、再多道次冷轧、再退火的循环处理,要求循环处理次数不少于3次。最终可获得抗拉强度大于950 MPa和导电率大于70 ％IACS的铜合金板材。添加稀土元素既增大了合金板材的导电性,又降低了层错能；高能球磨混粉、高温固溶、冷轧和去应力退火的循环处理工艺,保证高密度、理想孪晶厚度组织的形成。

The invention relates to a preparation method of high strength and high conductivity rare earth Cu-Ni-Si-Cr Alloy, which belongs to the field of lead frame materials. The alloy consists of .5-3.5％Ni, 2.0-3.0％Si, 1.5-2.0％Cr, 0.1-1.0％Ce, 0.1-0.6％Pr and 0.1-0.6％Nb. The rest are Cu and unavoidable impurities. The raw material powder is first put in the high energy ball mill to make it mix evenly and carry out pre–reaction, then it is added into the vacuum melting furnace with pure copper and melted by electromagnetic stirring. After casting and forging the billets, they are treated by high temperature solid solution, and then they are subjected to multi–pass cold rolling, annealing, multipass cold rolling and reannealing. Finally, copper alloy sheets with tensile strength greater than 950 MPa and conductivity greater than 70 %IACS can be obtained. The addition of rare earth elements not only increases the electrical conductivity of the alloy plate but also decreases the stacking fault energy, but also guarantees the formation of high density and ideal twin thickness microstructure by high energy ball milling, high temperature solid solution, cold rolling and stress relief annealing.