Improvement of machinability of Waspaloy via laser-assisted machining

Waspaloy is a heat-resistant alloy primarily used in aircraft turbine engines, as forged turbine and compressor disk, which is difficult to machine at room temperature due to excessive tool wear and poor surface finish. Laser-assisted machining (LAM) offers the ability to machine such superalloys more efficiently by locally heating and softening the workpiece material prior to material removal and machining with a conventional single-point cutting tool. A transient, three-dimensional heat transfer model is used for modeling LAM of Waspaloy. The thermal model is validated by comparing the temperature predictions and the surface temperature measurements using an infrared camera. The machinability of Waspaloy under varying conditions is evaluated by examining tool wear, cutting forces, and surface finish. With increasing material removal temperature from room temperature to 300–400°C, the benefit of LAM is demonstrated by a 20% decrease in specific cutting energy, a two- to three-fold improvement in surface roughness, and a 50% increase in ceramic tool life over conventional machining.