Evaluation of the Machining Aspects of Austempered Ductile Iron

Abstract

Exceptional properties, such as wear resistance, high strength and ductility, predestine austempered ductile iron (ADI) to substitute for forged steel, aluminum or ductile iron in technical components and parts. The advantages of ADI can be ascribed to the austenitic-ferritic matrix produced in a two-step austempering process. Even though ADI is already established for some industrial applications, machinability in the heat treated condition still hinders a more extensive usage. The machining of ADI is still ambitious, and especially the metallurgical aspects, such as the influence of the chemical composition and the cast skin, have not been taken into account in recent machining investigations. In this paper, the influence of the above mentioned metallurgical aspects on machinability are described and adapted machining strategies to counteract these obstacles will be presented.