Investigations on laser-assisted turning of IN625 alloy with hot hardness approach using uncoated and CrAlSiN coated WC tools

Abstract

This paper presents an investigation into the effect of laser-assisted turning of the IN625 superalloy using uncoated and CrAlSiN nanocomposite-coated tungsten carbide tools. A hot hardness test was conducted for IN625 material, which showed there was a pronounced softening of the material above 850 °C. This exercise guided the choice of laser power for the subsequent laser-assisted turning experiments. The cutting forces (radial/thrust, Fx; axial/feed, Fy; and tangential/cutting, Fz), maximum flank wear (VBBmax), and surface roughness ( Ra) were measured and analyzed for the planned experiments. The results demonstrated that at 2500 W laser power, a 9%, 70%, and 59% reduction of cutting forces for uncoated tools, and a 31%, 77%, and 69% reduction for CrAlSiN coated tools were observed in the Fx, Fy, and Fz directions respectively. At 2250 W laser power, the uncoated tools exhibited a 33% (433–289 µm) reduction in VBBmax and a 28% (1.8–1.3 µm) reduction in Ra. The CrAlSiN-coated tools, at 2500 W laser power, showed even more significant improvements, with reductions of 46% (365–232 µm) in VBBmax and 56% (1.4–0.8 µm) in Ra. The results underline the improved performance of laser-assisted turning for cutting-force and tool-wear reduction and improved surface finish with CrAlSiN-coated tools. This paper presents the potential of laser-assisted machining as a viable method for machining difficult-to-machine materials like IN625, which offers enormous manufacturing productivity and tool life benefits.