The machining of compacted graphite irons–State of the art and future perspective

To comply with stricter emissions regulations and enhance engine performance, the automotive industry is progressively substituting conventional gray cast iron (CI) with compacted graphite iron (CGI) due to its superior heat transfer performance and mechanical strength. Although CGI possesses impressive mechanical properties, its poor machinability constrains its wider application within the automotive sector. This review synthesizes recent developments and achievements, including the material removal mechanism, associated cutting tools, surface quality and lubrication techniques in CGI machining and indicates the direction for future research and development. Future research should address these challenges through the integration of hybrid machining techniques utilizing multiple energy fields and AI-based process optimization to improve real-time adjustments. These advancements will not only enhance machining efficiency and tool life but also facilitate the broader industrial adoption of CGI in automotive and engine manufacturing.