具有立方形态析出组织的耐高温铜基超合金设计

在高温、重载等严苛环境下，高强导电铜合金必须抗高温软化，而析出强化铜合金的软化温度不超过650°C，不能满足高温内衬及特殊电接触材料等的特殊需求。借鉴镍基超合金用“立方形态γ'-Ni3Al相在面心立方γ相上共格析出”的特殊组织，能实现近0.9熔点的承温能力，本项目采用团簇式成分设计方法，发展具有类似组织特征的新型Cu-Ni-Al基超合金。前期研究已经获得软化温度高于1000℃的耐热铜合金，但是导电性能没有兼顾。拟在此基础上基于团簇式[(Al,Ni)–(Cu,Ni)12](Al,Cu)3成分框架，通过多组元化提升γ'相的稳定性，并保证铜基体的固溶元素尽量析出以获得高导电性，协调元素间相互作用、调整点阵匹配以获得立方形态析出组织提升合金强度和耐温性。最后从近程序出发梳理元素间相互作用机理，建立团簇式成分、组织与合金性能变化的定量关系，为发展耐高温导电铜合金提供一个新的解决方案。

High temperature softening resistance is an important property for high strength and conductivity copper alloys in service under high temperature, high voltage, high current and heavy load, etc. However, the softening temperature of ordinary copper alloys can only achieve about 650 °C, which cannot satisfy the increasing demands of high temperature lining and special electric contact materials. In view of the fact that common nickel-based superalloys can achieve a temperature bearing capacity of nearly nine-tenths of the melting point of nickel by the special structure of "cuboidal γ'-Ni3Al phase coherent precipitation on the face-centered cubic γ phase solid solution". In this project, the cluster composition design method will be introduced to develop a new Cu-Ni-Al-based superalloy with similar structure characteristics. The preliminary results also showed that heat-resistant copper alloys with a softening temperature above 1000 °C can be obtained but the conductivity is undesirable. Based on the previous research and the composition framework of cluster formula [(Al,Ni)–(Cu,Ni)12](Al,Cu)3, the stability of the γ' phase will be improved through multi-component, and meanwhile the high conductivity will be obtained by ensuring that the solutes in the copper matrix are precipitated as far as possible. Moreover, the strength and temperature resistance of alloys will be improved by the cuboidal precipitation structure, which achieves by coordinating interactions between elements and adjusting lattice matching. Finally, the interaction mechanism of elements will be analyzed based on the short-range order, and the quantitative relationship between composition, structure and properties will be established, which provide for developing high temperature resistant conductive copper alloys.