High-pressure cutting fluid supply is widely used in rough turning of difficult-to-cut materials to ensure chip breaking. The acting force of the cutting fluid jet on the back of the chip causes chip breaking. The broken chips are accelerated by this force and can damage the workpiece surface on impact. Consequently, high-pressure cutting fluid supply is not suitable for finish turning mostly, especially for safety-critical parts in aero engines. In this study, a new approach to utilize the high-pressure cutting fluid supply for finish turning is presented. A valve unit is used to alternate the cutting fluid supply pressure in short time intervals. The generated pulsation allows to adjust the chip length. An adjusted chip length changes the center of gravity of the chips. Therefore the chips are accelerated to a much lower extent, which prevents surface damage. The force of the cutting fluid jet was investigated for different pressure levels and pulse frequencies. Machining experiments confirmed the working principles by showing a correlation between the pulse frequency and the resulting chip length.
Science Journal 