Tool wear mechanisms in laser-assisted milling of Nickel-based superalloys

Abstract

Nickel-based superalloys are widely used in the manufacturing of aero-engine turbine disks, compressor disk, and other essential parts. The processing mechanisms result in low machinability due to the combined properties of high-temperature hardness, mechanical strength, and wear resistance. Laser-assisted machining (LAM) is a hybrid method to machine difficult-to-cut materials with the advantage of high machining efficiency, low tool wear, and high machining quality. In order to maintain the constant preheating temperature, the infrared temperature measurement point is set as a feedback value, and the laser energy is controlled by the system to ensure the milling zone preheating temperature maintaining a stable value. Laser-assisted milling (LAML) and conventional milling experiments are conducted on Inconel 718 using TiAlN coated carbide tools. Tool wear mechanisms are analyzed to investigate the influence of machining parameters on tool wear. The main results indicate that tool wear mechanisms in LAML are similar to the conventional milling, and adhesion wear is found to be the primary phenomenon leading to the milling tool wear. Tool life is longer in LAML due to the soften material and decreasing impact action on the milling tool. Besides, PVD and CVD coated carbide milling tools are used in LAML, and the experimental results show that CVD coated tool is better at the higher temperature, and it is more suitable for LAML of Inconel 718. At last, orthogonal experiments for the tool life are conducted using CVD coated tools, and the influence factors and estimation method of tool life are presented.