Comparative study on machinability and surface integrity of γ-TiAl alloy in laser assisted milling

γ-TiAl alloy, as a typical difficult-to-cut material, is considered to have great potential in aero-engine manufacturing. However, it is difficult to achieve high-quality processing of γ-TiAl alloy using traditional cutting processes, due to the room temperature brittleness and high strength of theγ-TiAl alloy. This study proposes a fiber laser assisted machining (LAM) method to improve the cutting quality of γ-TiAl alloy, which attempts to address current challenges in applications of aero-engine manufacturing. The machinability and surface integrity of γ-TiAl specimens using LAM method and conventional milling are analyzed and discussed. Through cutting force testing, chip morphology research, surface hardness testing, and microstructure observation, it is found that the LAM method significantly improves the machinability and machined surface integrity of γ-TiAl specimens. Furthermore, the cooling strategies in LAM is discussed through comparative cutting experiments. During continuous LAM processing, it is found that the rapid heat accumulation effect induces tool adhesive wear, which leads to the decline of cutting quality and tool failure. The experimental results indicate that liquid cooling is an available strategy to reduce tool wear. However, it should be noted that periodic thermal shock by liquid cooling causes surface roughness to increase in continuous LAM processing. Through this work, it is proved that the LAM method can improve machinability and surface integrity of γ-TiAl specimens, which has great potential and worths further studies.