Investigation of the influence of MWCNTs mixed nanofluid on the machinability characteristics of PH 13-8 Mo stainless steel

In recent years, advances in nanotechnology have been positively reflected in the manufacturing industry, as in many other fields. Owing to their physical and chemical aspects, the nano-sized solid lubricants can help to improve the tribological and thermal properties when added to aerosols, suspensions and emulsions. In order to achieve high efficiency in machining operations, this phenomenon provides an opportunity to perform the tasks expected from a coolant/lubricant. Therefore, this study aimed to investigate the influence of cutting fluid reinforced by multi-walled carbon nanotubes (MWCNTs) into vegetable based cutting fluid on machinability characteristics of PH 13-8 Mo stainless steel that has excellent mechanical properties. For this, Taguchi's L27 (3(3)) orthogonal array involving three factors and their three levels such as cutting speed of 120, 180, 240 m/min, feed rate of 0.1, 0.15 and 0.2 mm/rev and three C/L environment i.e., dry, pure-MQL (0 vol% of nano-additives) and MWCNTs mixed nanofluid-MQL were taken as process parameters. In this experimental design, surface roughness and peak temperature in cutting zone were considered as responses. Moreover, to analyze only the influence C/L environment on tool wear, wear mechanisms and surface topography, a series of experiments were conducted by preserving other machining parameters. As a result, approximately 5% and 12% lower surface roughness was achieved with pure-MQL and nanofluid-MQL, respectively. The reduction in flank wear was found to be 40.2% and 69% under cutting environment, i.e., pure-MQL and MWCNTs mixed nanofluid-MQL.