Evaluation of the effect of application of cutting fluid at high pressure on tool wear during turning operation of AISI 316 austenitic stainless steel

The application of high-pressure coolant (HPC) in cutting processes can strongly influence the wear on the cutting tools providing a longer tool life. This is possible due to better penetration of the fluid into the tool–workpiece and tool–chip contact region, providing a better cooling effect and decreasing tool wear through lubrication of the contact areas. To better understand the effect on tool life, it is necessary to investigate wear mechanisms, as these depend on the frictional/thermal conditions at the tool–chip interface. The objective of this work is to study how tool wear mechanisms are influenced by cutting fluid applied at high pressure and in different concentrations in the turning operation of AISI 316 austenitic stainless steel using coated cemented carbide tools. The experiments were carried out in a turning operation and the cutting fluid was applied at different pressures (10, 15 and 20 MPa) between the chip and tool at the rake face. The results are compared to dry cutting and wet cutting. Cemented carbide tools of class ISO K coated with TiN, Al2O3 and Ti (C,N), using the chemical vapor deposition at medium temperature technique (MTCVD), were employed. The main findings were the reduction of tool wear and reduced tool-chip contact length with the use of high-pressure coolant. The main wear mechanism observed on the rake face and the flank face was adhesion. The high-pressure coolant technique was more efficient than both overhead fluid applications and dry cutting with regard to the reduction of cutting tool wear. The lowest wear was obtained when the fluid was applied with a concentration of 10% and at a pressure of 10 MPa.