Development of Novel CBN Cutting Tool for High Speed Machining of Inconel 718 Focusing on Coolant Behaviors

Nickel-based superalloys such as Inconel 718 are known as one of the most difficult-to-cut materials due to their mechanical and chemical properties and the tool life is extremely short. Recently, Cubic-Boron-Nitride (CBN) has received considerable attention as a material for cutting tools and has already established itself in many areas of machining. However, the performance of CBN tools is still insufficient in practical use, especially in the high speed machining of Inconel 718. To overcome this problem, cutting experiments on Inconel 718 at a wide range of cutting speeds (100 m/min - 500 m/min) were conducted and the performance of CBN cutting tools under dry and wet cutting conditions was evaluated. Based on the result, we newly developed a CBN cutting tool with a textured flank face with the aim to enhance the effect of cutting fluid at the tool-workpiece interface. Experimental results showed that the textured flank face improved the wear resistance of the CBN cutting tool in the high speed machining of Inconel 718.