Evaluation of surface roughness in face milling of austempered ductile iron (ADI)

Abstract

The use of austempered nodular cast iron (austempered ductile iron – ADI) in engineering projects has gained notoriety due to its mechanical properties such as high strength and hardness combined with high ductility. The rise in the use of this material in the civil construction, mining, automotive, agricultural and railway industries has increased the demand for more elaborate studies regarding the machining of this material. In the front (or top) cooling of the ADI, the thermal and mechanical effects that occur during machining can cause changes in the quality of the machined surfaces and their hardness. This work aims to study the relationship between the cutting parameters used in face milling and the quality of ADI machined surfaces. The milling tests used a carbide tool and the cutting speed, cutting depth and use or not of lubricant-coolant fluid were varied. Subsequently, the roughness parameters Ra and Rz were measured for each condition evaluated. The evaluation of the Vickers hardness of the machined samples complemented the study. Considering all the machining conditions evaluated in this work, all Ra roughness results were below 1.2 ?m and all Rz roughness results were below 5 ?m, presenting an excellent surface finish of the ADI.