Research On Mechanism And Surface Integrity Of Precision Abrasive Belt Grinding Of TiAl-based Alloy Thin-wall Component

As a new type of composite material that is favored by the international community,TiAl-based alloy has the advantages of low density,high specific strength,high temperature creep resistance,and strong oxidation resistance compared with titanium alloy and nickel-based superalloy,it has broad application prospects in the aerospace field.However,TiAl-based alloy has low plasticity and high brittleness and poor processability,and it is difficult to meet the processing requirements by using traditional mechanical processing methods.Therefore,the development and application of TiAl-based alloy are restricted to a certain extent.This paper focuses on the problem that the surface of TiAl-based alloy thin-walled component is difficult to process.Using a combination of simulation and testing,and a grinding method for the "flexible" precision machining of TiAl-based alloy is proposed.The main research work completed in this paper is as follows:(1)The characteristics of material Machinability and processing distortion of TiAl-based alloy are analyzed,and the mechanism of single-grain abrasive cutting and surface grinding is analyzed.It will lay the foundation for the establishment of the trajectory model of abrasive grain movement in consideration of the deformation and wear,and the profile grinding strategy of the thin-walled component is analyzed.(2)The influence mechanism of grinding contact state on the grinding material removal of TiAl-based alloy is analyzed.The spatial motion trajectory model of the abrasive grain movement in consideration of the deformation is established.The precision grinding parameters of TiAl-based alloy is determined in combination with finite element simulation and basic experiments,which can provide theoretical basis for follow-up experiment research.(3)The least squares method and power spectral density analysis method are used to process the surface morphology data of the collected belt.The numerical simulation method is used to simulate the surface morphology of the belt,and a prediction model of the abrasive wear height of the belt is established to optimize the spatial motion trajectory model in consideration of the abrasive wear.The simulation algorithm of TiAl-based alloy workpiece surface grinding topology is created,and the topography and surface roughness of the simulated and measured are analyzed and compared.(4)The orthogonal experiment of precision grinding of TiAl-based alloy is carried out,and the grey correlation method is used to determine the optimal grinding process parameters.The grinding surface integrity is studied from the aspects of surface roughness,surface hardness,residual stress and surface morphology.The grinding test of thin-walled component with complex surface is carried out,and the quality of surface grinding is analyzed.The feasibility of abrasive belt grinding of TiAl-based alloy thin-walled member is verified.