Effect of minimum quantity lubrication aerosol temperature on tool life in machining AISI P20 and D2 steels using coated tungsten carbide tool inserts

This study focused on turning AISI P20 and D2 tool steels using coated-carbide cutting tools. In this experimental investigation, an emulsion cutting fluid (CF) aerosol temperature with minimum quantity lubrication (MQL) was varied from 5 °C to 20 °C and its effect on the tool life was evaluated. Trials were done for dry cutting and flood cooling at 25 °C also in same conditions. MQL revealed better tool life for both steels than dry cutting and flood cooling. The tool wear for P20 showed a quadratic behaviour against aerosol temperature, with minimum occurred at 15 °C. At 15 °C, 97% and 93% tool wear reductions were observed from dry cutting and flood cooling respectively. However at 20 °C, tool wear increased by 29% from flood cooling. For D2 steel, similar characteristics were observed with minimum wear at 15 °C. A wear reduction of 96% from dry cutting, and 93% from flood cooling was observed with at 15 °C. MQL at 15 °C leads to a potential means of reducing machining costs. However, trials need to be repeated with different tool material, work-piece material and aerosols to ascertain the generalizability of the findings.