Wear reduction mechanism in modulated turning of nodular graphite iron with coated carbide tool

Modulation-assisted machining (MAM) is used for turning nodular graphite iron (NGI) with coated carbide tools and compared with conventional machining (CM) at the cutting speed of 350 m/min in dry and wet conditions. Significant reductions in flank wear are achieved using MAM as compared to CM turning, in both dry and wet conditions. Dry MAM results in even lower wear than wet MAM condition. The substantial wear reduction in dry MAM is due to the formation of two material layers (i.e., the MgO deposition layer and the stagnated iron layer) and their unique arrangement on the flank face of the tool. The protective effect of these layers and the MAM conditions conducive to the formation of these layers are discussed.