Research Of Machined Surface Quality And Metamorphic Layer Characteristics Of Contour Bevel Gears

In the field of mechanical transmission,gear transmission has the advantages of small center distance and high transmission ratio,and is used in most manufacturing industries.However,dry milling of contour bevel gears generates high cutting forces and cutting temperatures,which can easily lead to poor machined surface quality and low machining efficiency,as well as plastic deformation of the workpiece material,resulting in uneven distribution of its metamorphic layer.In this paper,based on the principle of contour bevel gear milling,the machined surface quality and metamorphic layer of contour bevel gears are investigated through finite element simulation and experimental investigation.Firstly,based on the meshing theory of contour bevel gears and the principle of milling by the generating method,the local conjugate conditions of gears are investigated and the coordinate system of milling is established;the formation mechanism of the average residual height of tooth surface is explored according to the cutting surface model of gears and the mathematical model of tool cutting;the influence of cutting parameters on the residual height of tooth surface is analyzed through simulation and a method of characterizing the residual height of tooth surface is established.By simulating and analyzing the variation of cutting parameters on tooth surface residual height.Then,according to the actual milling process of contour bevel gears,the machining tool and tooth blank are reasonably simplified,and the DEFORM simulation software is used to assemble the parts,divide the mesh,define the boundary conditions and solve the operation;the main cutting force,the temperature field,strain field and strain rate of the metamorphic layer at different depths from the machined surface are extracted,and the influence laws of cutting parameters on them are analyzed;the Ga genetic algorithm is used to analyze the cutting temperature and strain rate under different cutting parameters,which provides a theoretical basis for studying the quality of the machined surface and the formation of metamorphic layers.Again,the dry milling test of contour bevel gears is conducted to analyze the effects of cutting speed and feed on the machined surface roughness and surface morphology of the workpiece;the surface defects on the machined surface of the workpiece are studied by scanning electron microscopy,and the causes of surface defects are analyzed by EDS;the microscopic grains of the machined surface and the substrate material arre compared by XRD,and the effect of cutting parameters on the machined surface of the workpiece is investigated in combination with the work hardening test.The effect of cutting parameters on the hardness of the machined surface is investigated.Finally,the machined gear wire-cut cross-section specimens are mosaiced,and XRD is used to diffract the machined metamorphic layer to investigate the grain refinement and phase transformation of the material;the metallographic morphology of the machined metamorphic layer of the workpiece is observed by ultra-deep field microscopy,and the work-hardening behavior of the surface metamorphic layer under different cutting parameters is investigated;the morphology of the machined surface metamorphic layer is observed by scanning electron microscopy to investigate the effect of cutting parameters on the machined surface metamorphic layer.The effect of cutting parameters on the thickness of the machined surface metamorphic layer is investigated.