Laser-assisted milling of difficult-to-machine materials

The Fraunhofer IPT has developed and realized a novel approach for laser-assisted milling of difficult-to-machine materials like nickel-base or titanium alloys. Tool integrated laser optics allow a precise heat input into the work piece by direct irradiation of the chip surface aiming at a reduction of material strength at elevated temperatures. Applying the new concept process forces and tool wear can be reduced by approx. 50%. The following paper comprises a description of the new technology as well as process results for laser-assisted milling of nickel-base and titanium alloys. Thermal investigations on the new approach for laser-assisted milling verify that the temperature range for a significant reduction of material strength can be reached. Machining results of Inconel 718 using a TiAlN-coated cemented carbide cutting tool show a significant decrease in process forces and flank wear. Depending on the laser power the cutting force Fy can be reduced by 60%. With laser-assistance and optimized laser parameters the cutting force Fx in direction of feed is reduced by 40%. For the cutting force Fy and the passive force Fz a decrease of 60% can be achieved.