Effects of Cu on the Morphology and Growth Mode of Graphite in Compacted Graphite Iron

Abstract

In this article, Cu is found to have a great influence on the graphite morphology and growth mode in compacted graphite iron (CGI). Metallographic pictures show that the number of vermicular graphite of the surface of CGI casting is significantly higher than that of the core, and there is more spheroidal graphite in the core of casting. In addition, a special form of graphite, which is defined as distorted graphite appears in the matrix. From the EPMA results, it can be concluded that the segregation of Cu promotes the distortion of graphite, and part of distorted graphite is transformed into vermicular graphite under the action of vermicular elements (Mg, La, and Ce). The increase in the number of spheroidal graphite improves the strength of casting, but it reduces the thermal conductivity.