Machining of Compacted Graphite Iron: A review

Compacted Graphite Iron (CGI) represents a unique combination of the characteristics of grey and spheroidal cast irons, sparking significant interest over the past two decades, particularly as a favoured material in several automotive industry applications, including engine components and heavy-duty vehicle parts. Despite its growing prominence, the full potential of CGI remains underutilised, primarily due to its lower productivity rate compared to grey cast iron. This paper comprehensively reviews existing research on CGI machining, emphasising the challenges and exploring opportunities for development in this field. A detailed comparison between the machining of compacted graphite iron, grey cast iron and spheroidal graphite cast iron is provided, highlighting the unique characteristics associated with CGI. The influence of microstructure and chemical composition on machining processes is thoroughly examined and deliberated. Moreover, this review delves into the effects of various process variables on CGI machining, including cutting tools, lubrication, and cooling methods. The paper concludes by discussing potential future trends and innovations in CGI machining, offering a prospective outlook on how these developments could bridge the productivity and literature gap and enhance the utilisation of CGI in industrial applications.