The effect of alloying elements on surface roughness and cutting forces during machining of ductile iron

Due to its enhanced strength, ductility and toughness, ductile iron has poor machining properties when compared to flake graphite cast iron. However, when a steel part is replaced with ductile iron, better machinability is considered to be the most important gain. This study presents the results of machining tests of ductile irons (DIs) alloyed with Ni and Cu at various amounts to determine the effect of their microstructures and mechanical properties on cutting forces and surface roughness. Six different groups of ductile iron specimens alloyed with various amounts of Ni and Cu were subjected to machining tests and their machinability were investigated based on cutting forces and surface roughness criteria. The results show that alloying ductile iron with Ni and Cu at various amounts affected cutting forces developed during turning and surface finish of the machined components significantly, in terms of both criteria, the best results obtained were for the specimen alloyed with 0.7% Ni and 0.7% Cu.