Author : Gaurav Sharma and Radhey Sham

The industrial application of compacted graphite iron in the automotive industry is taking a rather long time due to its uneconomic machinability, because of a significant decrease in tool life. After six years of holistic research of the PTW in cooperation with foundries, manufactures and material scientists, the wear mechanism was understood and clarified: Sulphur in the microstructure of cast iron has direct influence on the formation of a manganese-sulphur layer on the cutting edge. For machining gray cast iron this layer protects the cutting edge against abrasive wear. In case of CGI no layer formation occurs. Against the abrasive wear new cutting materials and tools for the machining of CGI must be developed. Compacted Graphite Iron (CGI) has an important role in manufacturing of new generation engines. Better strength of CGI, as compared to flake graphite iron (FGI), allows CGI engine to perform at higher peak pressure. This can give higher fuel efficiency and lower emission rate. However, the machinability of CGI is poor as compared to FGI. The machinability of CGI is an area that needs to be studied in a better way to cut the production cost of the engine. It is a well-known fact that the as-cast engine block has varying microstructure and mechanical properties due to different cooling rates at different locations of such a geometrically complex component. This has highlighted the need for studying machinability as a function of microstructural and mechanical properties so that the machining process could be optimized.

Keywords: Parametric Optimization, CGI, Milling Machine

Article published in International Journal of Current Engineering and Technology, Vol.5, No.5 (Oct-2015)