Influence Of The Honed Cutting Edge Geometries On Cutting Performance Of Cemented Carbide Tools

With the development of machining technology,metal cutting has higher and higher requirements for tool performance.Edge passivation is a key technology to improve cutting performance in the process of tool manufacturing.The micro geometry of the edge after passivation has an important impact on the machining performance and service life of the tool.Because the passivated edge is a micron level complex shape and is not a regular arc,using a simple blunt circle radius can not accurately describe the shape of the edge.At present,there is no unified standard for the accurate description of blade shape.There is also a lack of theoretical basis for the shape control of edge passivation in practical production.There is no systematic research on the cutting performance of tools with different passivation shapes.Firstly,according to the characteristics of the micro geometry of the tool edge after passivation,combined with the existing edge description methods,a new edge characterization method is proposed in this dissertation.This method uses five shape parameters to divide the cutting edge into front and back knife surface passivation area and transition area,which can intuitively describe the shape of the passivated cutting edge.Based on this characterization method,the edge contour fitting methods of analytical method and geometric method are proposed,which proves the feasibility of this method.Based on this method,with the help of metal cutting principle,the process of chip forming affected by edge shape and the source of cutting force are analyzed.Cemented carbide blades with different shapes of cutting edges were obtained by using a vertical brush passivation machine.The dry cutting experiments of 42 Cr Mo were carried out with these passivated blades,and the effects of edge shape on the wear degree of front and rear tool surfaces and chip shape were analyzed.The model is established according to the blade edge shape,and the finite element cutting model is established based on DEFORM software.The Usui wear model is optimized with the help of experimental and simulation results.Finally,the orthogonal cutting experiment is designed according to the five shape parameters of the new characterization method.Through the two-dimensional right angle cutting simulation,the cutting performance indexes such as cutting force,cutting temperature,tool wear degree and workpiece surface residual stress are obtained respectively,and the significant factors affecting the cutting performance are analyzed.The influence law of edge shape on cutting performance is summarized,and the principles of edge passivation are put forward,which provides a new idea for the research of edge passivation shape in the future.