Research On NC Machining Technology Of Ni₃Al-Base Superalloy Turbine Disk

As the key component of turbine machinery of aero-engine, integrated turbine disk has an extremely severe working environment with high temperature and alternating shock load, which requires the high performance of turbine disk materials. Ni3Al-base superalloy is one kind of new materials which is suitable for integrated turbine disk for its good oxidation resistance as well as corrosion resistance and creep resistance and excellent fatigue life at high temperature. However, good physical and mechanical property often means poor machinability. Especially, the machining efficiency and manufacturing precision of the turbine disk are low because of the big cutting force, low machined surface quality and severe tool wear during the cutting process. Meanwhile, the structure of integrated turbine disk is more complicate than before due to the requirement of big thrust-weight ratio and high efficiency of aero-engine. This research focuses on the high temperature alloy turbine disk with long-short blade. Machining of this kind of turbine disk becomes very difficult for tool and cutting deformation would be often happened, which requires high stability for machining process.This paper conducted investigation on the NC Machining technology of Ni3Al-base superalloy turbine disk using coated carbide tool and solid ceramic end tool, and discussed the cutting force, tool wear and surface quality. Results obtained can provide basic data and theoretical reference for the efficiency and precision milling of Ni3Al-base superalloy turbine disk.This paper mainly completes the following work:1. The processing technology of Ni3Al-base superalloy turbine disk is investaged. According to the geometric structure characteristics of the whole turbine disk, the processing route is established. The cutting tool is selected, and the parameters are established.2. The machinabiligy is studied based on analysis of force, surface quality and tool wear during milling of Ni3Al-base superalloy. The cutting tool and cutting parameter is accordingly selected.3. The NC machining method of Ni3Al-base superalloy turbine disk using coated carbide tool is explored. The contour precision and surface quality during machining were detected. A favorable processing process specification is accordingly provided.