WEAR OF COATED HIGH-SPEED-STEEL MILL IN THE MACHINING WITH MINIMAL QUANTITY OF LUBRICANT

The milling process is one of the most important machining processes when it comes to the manufacture of molds and dies. The aspects such as high rate of material removal, as well as being a process with great flexibility, grant the milling a great employment in the industry. It's known that the mill's life state has direct effect in the mold's life. The effect of the interrupted cut, the friction between the workpiece and the tool, induce to an increase of the tool's wear. An almost dry condition, such as the application of MQL, has proven to decrease the friction, which leads to an increase of the tool's life. Also, using a coating film helps to increase the tool's life, by providing a higher mechanical resistance. In this context, this work presents a wear analysis of HSS AISI M2 mills coated with titanium nitride (TiN) in the machining with minimal quantity of lubricant (MQL). The cutting parameter varied was the axial depth of cut (a_p), although the cutting speed was kept constant at 50 m/min. Thus the objective of this study was to evaluate the mechanisms and types of wear with the change of the cutting parameter.