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

Turbine disk is one of the core components of aeroengine,which plays a key role in improving the thrust-weight ratio and reliability of the engine.Ni₃Al-based superalloy has good oxidation resistance and corrosion resistance at high temperature,which is very suitable for turbine disk.The efficient manufacturing production of turbine disk usually uses CNC machining methods.But the tool is prone to interference during machining,and the existence of tool deformation reduces the machining accuracy.In this paper,the NC machining accuracy control in machining of Ni₃Al-based superalloy turbine disk is discussed.The processing performance of Ni₃Al-based superalloy,the calculation of interference-free tool path,the prediction of tool deformation and the compensation method of tool deformation error were studied.The main research work included the following three aspects:?1?The variation law of cutting force of cemented carbide coated milling cutter milling Ni₃Al-based superalloy under different cutting parameters was studied,and the empirical formula of milling force was derived.Through the analysis of tool wear form and the study of tool durability,the performance of the selected tool for milling Ni₃Al-based superalloy material was comprehensively evaluated,which provided an important basis for the cutting parameter selection.?2?The algorithm of tool axis vector control was studied.The tool path was obtained by NC programming,including the roughing of the runner,the finishing of the blade,the finishing of the hub surface and the clearing of the root of the blade.The correctness of the tool path calculated by the control method of the tool axis was verified by the verification test of the CNC machining of the integral turbine disk.?3?A distributed-force segmented cantilever beam model was established to predict the actual deflection of milling cutter during milling.A flexible iterative error compensation model based on milling stability was established.The experiment of error compensation was carried out by this method.The compensated blade surface precision and surface roughness met the design accuracy requirements,which verified the effectiveness of tool deflection error compensation method.