Austempering Parameters and Machinability of Austempered Ductile Iron: A Comprehensive Review on Effective Parameters
Austempered ductile iron (ADI) formed by austempering of nodular cast iron (NCI). ADI has good mechanical properties due to the matrix of ausferrite (austenite, ferrite and graphite nodules). It gives good combination of high strength to weight ratio, fatigue resistance, ductility and toughness. Austempering process offer ability to access to a wide range of characteristics with appropriate selection of heat treatment parameters. Graphite nodules give ductility to material and also act as crack arrester and give good fatigue strength. ADI is strain hardening or work hardening material, it has property to go for strain induced transformation (SIT) while straining. When high normal force is applied to ADI while machining, austenite on surface undergoes to SIT and form martensite. This makes further machining even more difficult and reduces performance of cutting tool. This paper deals with detail study of ADI, effective austempering parameters and performance of different cutting tools at various input machining parameter while machining ADI.