Effect of remelting on the properties of low-alloy copper-iron alloy

Current machine building technologies place a demand for low-alloy copper alloys that would offer a combination of high electrical conductivity and mechanical performance. Today, low-alloy copper-iron alloys appear to offer more innovation than commercially pure copper as they find a wide application when designing innovative machine parts produced by casting. Low-alloy Cu – Fe alloys are precipitation hardening alloys which acquire greatly increased strength and electrical conductivity after heat treatment. A primary smelting and casting process has been developed for such alloys on the basis of commercially pure metals and alloys, as well as a secondary melting process applicable to waste copper-iron alloys. Application of the foundry process implies a repeated reutilization of in-house waste generated after every new melt. Such waste should be used as burden materials when casting alloys. This research was aimed at developing a process for utilization of secondary materials (i.e. in-house waste) to produce a low-alloy Cu – 2.65% Fe alloy. The authors examined the mechanical properties and electrical conductivity of such alloy after secondary melting. To obtain a quality melt, diffusion carbon deoxidation should be replaced with bulk phosphorus deoxidation. The resulting alloy has high strength and electrical conductivity, especially after heat treatment. High aggregate properties of double remelted Cu – 2.65% Fe alloys were established. This conclusion is also confirmed by the results of an electron microscopy study of the as-cast and as-heat treated alloy. The research was carried out within the state assignment of the Ministry of Science and Higher Education of the Russian Federation (theme FZUN-2020-0015, state task of the Vladimir State University).