High-speed grooving with applying MQL

The performance of minimum quantity lubrication (MQL) in high-speed cutting was evaluated in grooving 0.45%C carbon steel with a carbide tool coated with TiC/TiCN/TiN triple coating layers. MQL with supplying vegetable oil at a small and constant rate of 7 ml/h reduced the corner and flank wears more effectively than a solution type of cutting fluid at high cutting speeds of 4 and 5 m/s. In MQL grooving, the wears decreased drastically with increasing the pressure of air supply. This suggested that the air supply took an important role in transporting the oil mist to the interface between the flank wear land and machined surface. Then, a controlled oil mist direction (COD) tool was devised and its performance was proved to be high at a reduced rate of oil supply.