Study On Mechanism And Experiment Of Carbide Tool Passivation Based On Erosion Wear

With the progress of science and technology,manufacturing industry has achieved unprecedented development,and the requirements for cutting tools have increased accordingly,cemented carbide is widely used as tool material for machining various parts because of its high hardness,high wear resistance and high corrosion resistance.The tool performance affects the tool life and processing quality,tool performance is not only related to the material of the tool itself,but also related to the microstructure of the edge,currently mainly through the passivation process to change the micro-morphology of the edge,prolong the service life of the tool,improve the processing quality of parts.At present,there are many passivation methods,and the passivation effect is uneven,which is difficult to meet the needs of China’s tool industry.In this paper,the passivation mechanism of carbide tool is studied and the influence of different passivation parameters on the cutting edge is analyzed.A kind of tool passivation equipment is designed.The passivation experiment is carried out with this equipment,and the CFRP material drilling experiment is carried out with the passivation tool.The details are as follows:First of all,this paper elaborated the erosion wear theory,analyzed the erosion wear influence factors,combined with the characteristics of cemented carbide material and tool passivation process characteristics to establish a cutting edge material removal model,analyze the cutting edge material removal mechanism.Secondly,finite element method was used to establish simplified single and multiple abrasive erosion models with finite element software ABAQUS.Based on kinetic energy theorem and energy conservation theorem,the variation of abrasive velocity,abrasive displacement and energy in the process of abrasive erosion edge was analyzed at the micro level.The effects of erosion frequency,erosion Angle,abrasive material and abrasive particle size on edge stress and edge surface pit depth were studied.Thirdly,finite element and discrete element coupling method was used to establish the coupling model of abrasive flow erosion edge by using finite element software ABAQUS and discrete element software EDEM.The motion law of abrasive flow was studied,and the effects of erosion Angle,erosion velocity,abrasive number and abrasive shape on the edge wear rate were analyzed.Finally,based on the passivation characteristics of OTEC tool passivation machine and combined with laboratory conditions,a tool passivation equipment was designed,including feed unit,pose adjusting unit,passivation unit and support unit.Modal analysis of the support unit was carried out by using finite element software ANSYS.The carbide bit was selected as the research object,and the orthogonal experiment was designed.The passivation experiment was completed by using passivation equipment to verify the accuracy of the simulation results.The effect of passivation on tool life and machining quality of CFPR material was studied by drilling experiments with and without passivation bit.