Study On Three-dimensional Microstructure Performance Prediction And Crack Propagation Behavior Of Carbide Tool

The severe adhesion failure on Carbide tool occurred in the process of interrupted cutting large shell blank.The study shows a deterioration layer emerged on the tool rake surface due to the tool-chip elements mutual diffusion under the high temperature and pressure generated by the rake surface contact area.The tool and chip form a firm connection for the deterioration layer,so we call the deterioration layer welding layer.The internal defects in welding layer easily lead to adhesion failure on the tool rake surface,therefore,for this problem to establish three-dimensional microscopic model of tool rake surface,which can link microstructures with macro performance and provide a theoretical basis for revealing the essential cause of tool adhesion failure and improving the tool life.This paper based on the National Natural Science Fund(fund No.51575146)“Study on the damage mechanism of adhesion failure on the carbide tool rake surface in the process of heavy cutting”,ABAQUS is used to establish three-dimensional microscopic model of carbide tool rake surface to predict the material performance parameters and analyze the crack propagation behavior of the material.This paper studies from the following aspects.First of all,using Image J software to analyze two-dimensional SEM binarization images of carbide tool with welding layer and getting the microstructure parameters,and according to the parameters,MATLAB is used to generate WC(tungsten carbide)particles that meet the requirement average particle size,then Python was used to establish particles in ABAQUS and insert the Co phase.A model similar to the microstructure of the carbide tool rake surface is completed.Secondly,in order to better reflect the macroscopic performance of materials,the microstructure of carbide tools was analyzed,and the appropriate representative volume element(RVE)was selected to further simulate the model,and predict its elastic modulus,Poisson's ratio and surface hardness.Thirdly,the crack growth model of cemented carbide was built by embedding cohesive element in the microscopic model of the carbide tool rake face.The crack growth behavior was simulated,and the effect of combine force on the crack propagation path was studied.Finally,the force condition of welding layer was analyzed,combined with the formation of the micro crack in the actual cutting process.The crack propagation behavior of the welding layer is studied without initial cracks,prefabricated initial cracks and multiple cracks.The influence of cracks on tensile strength is comprehensively analyzed,which lays the foundation for the study of the exfoliation of the welding layer.