中文摘要：

通过真空感应熔炼制备了不同Ca含量的Cu—Ca亚共晶合金，研究了Cu-Ca铸态合金的显微组织和性能。研究表明，随Ca含量的增加，初生相α-Cu由等轴晶组织转变成树枝晶组织，共晶组织α-Cu＋β-Cu5Ca增多且呈网状分布在枝晶之间，合金的电导率降低，显微硬度上升，抗拉强度先上升后下降。通过对半固态组织形成机理分析认为，树枝晶组织有利于半固态成形工艺的应用。

英文摘要：

Cu-Ca hypoeutectic alloys with different Ca content were prepared by vacuum induction melting, the microstructure and properties of as-cast alloys were investigated. The results indicate that with the increase of Ca content, primary phase α-Cu transform to dendritic structure from equiax crystal, euteetic structure α-Cu＋β-Cu5Ca increased and distributed in the shape of continuous net among dendrites. The conductivity of the alloys decreases, the microhardness increases, and the tensile strength increases firstly and then decreases. According to analyzed the formation mechanism of semi-solid structure, the dendritic structure is propitious to the application of semi-solid forming process.