Research On The Design And Manufacture Of PCBN Tool With Cosine Enhanced Edge

PCBN tool is usually used for cutting in high speed hard cutting,while PCBN tool material is brittle,so negative chamfer is usually made on the cutting edge to improve the cutting edge strength and prolong the service life.But it can also make chip accumulate,increase the cutting resistance and cutting zone temperature,exacerbate tool wear failure.In order to improve the above problems,combined with the characteristics of spatial curve edge coordinating chip flow,a PCBN tool with cosine enhanced edge is designed in this paper.Combined with the structural characteristics of the tool and the grinding method of the machine tool,the near PCBN tool with cosine enhanced edge meets the requirement of machining precision which has been fabricated by linear approximation method.At the same time,the high speed hard cutting experiment was carried out between two kinds of tool,and the cutting performance was analyzed,which provided the theoretical basis for the development and application of the PCBN tool.First,the design and preparation methods of the PCBN tool with cosine enhanced edge are studied.Aiming at the problem of chip cooling and cutting resistance in cutting process,a PCBN tool with cosine enhanced edge is proposed,and the tool edge line is numerically simulated by MATLAB.Combined with the idea of face grinding and transformation,the approximate grinding path planning scheme is proposed.Combine with track simulation and grinding test,the grinding times are optimized.The accuracy testing method of parameters such as edge defect,chamfer width and angle are put forward.The quantitative evaluation of tool grinding accuracy is completed.Secondly,the high speed hard cutting experiment was carried out,the detection method of chip,crater wear and micro-structure of machined surface layer is put forward in this paper.The effects of cutting parameters and tool wear on cutting force and cutting temperature of two kinds of cutting tools are analyzed.On the basis of high speed photography,the influence of tool with cosine enhanced edge on the state of macroscopic chip outflow is studied,and then metallographic experiments are carried out to analyze the differences in microchip morphology.Finally,the wear process of two kinds of structural tools is analyzed.The area and depth of the crater wear,the distance between the wear area and the cutting edge,the length and width of the flank wear are used to evaluate the wear morphology of the tool,and the tool wear mechanism is revealed.Based on the wear characteristics of two kinds of tool,the characteristics of machined surface topography,white layer and residual stress are evaluated,and the advantages of tool with cosine enhanced edge are analyzed in cutting process.