An analysis of surface roughness in the hard milling of AISI D2 tool steel under MQCL condition using nano cutting oil

The paper aims to study the influences of the cutting speed, nanoparticle concentration, and feed rate on surface roughness Ra in the hard milling process under nanofluid Minimum Quantity Cooling Lubrication (MQCL) condition. Box-Behnken experimental planning design was used to formulate the experimental matrix and analyses the interaction effects among the surveyed factors. Based on the obtained results, the proper ranges of investigated variables were provided to reach the smaller surface roughness values for each specific condition. Also, the optimal set of cutting speed V=140m/min, nanoparticle concentration NC=0.3%, and feed rate f=0.01 mm/min was determined for the predicted minimal surface roughness Ra =0.107 µm, which is the useful technical guides for the further studies and machining practice.