Study on chip formation and surface integrity of nickel-based superalloy Inconel 718 by laser assisted micro-cutting

Inconel 718 is a typical refractory material with high strength and toughness. Laser-assisted machining (LAM) has been proved to have a positive effect on improving the machining performance of Inconel 718. However, there are few reports on the impact of micro-cutting chip formation process and machining surface and subsurface. This research adopts a laser-assisted local heating process for cutting a layer with a thickness of 5,15 and 20 μm and obtains the complete chip root with a quick-stop device. The temperature field distribution of laser irradiation and the chip formation process of orthogonal cutting are analyzed by finite element simulation. Through the experiment, we study the chip evolution of conventional machining (CM) and LAM and find that the thermal effect of laser makes. Additionally, the back side of the chip is relatively smooth, and the fibrous texture of the material due to extrusion fracture is comparatively sparse. Under the same conditions, the shear angle of LAM is 5° larger than that of CM, the residual stresses are all residual tensile stresses and greater than CM. Based on this, the surface quality of the workpiece and tool wear for CM and LAM conditions are analyzed through orthogonal cutting experiments. The results show that laser in the range of P = 70 W and V = 100–400 mm/s has obvious advantages in improving cutting quality and reducing tool wear.