Simulation And Experimental Study On Precision Grinding Damage Of Zirconia Ceramics Under Force-Heat Coupling

Engineering ceramic materials have been widely used in aviation,aerospace,military,automotive,transportation,civil and even electronic products important areas,due to their excellent performance on high strength,high hardness,wear resistance,high temperature resistance,chemical corrosion resistance and low density and toughening modification compared with steel materials.At present,engineering ceramic materials are mainly used for precision grinding of super hard fine abrasives.Due to its hard brittle,the surface/subsurface damage such as crack,pit and damaged layer is easy to occur during grinding,resulting in a decrease in the service performance and service life of the components.In this paper,zirconia ceramics are taken as the research subject,the dynamic mechanical properties of zirconia ceramic were developed.Combined with the dynamic mechanical properties of zirconia ceramics,the grinding simulation was carried out by considering the force thermal coupling effect.The influence of the coupling of force and heat on the grinding damage and the influence law of the process parameters on the grinding damage were analyzed.The simulation results were verified by experiments,and the precision grinding removal mechanism and damage mechanism of zirconia ceramics were studied to provide guidance for improving the quality of grinding.The main research contents of this paper are as follows:Firstly,based on the SHPB principle and the brittle material characteristics to improve experimental device,the dynamic mechanical properties of zirconia ceramics were studied,and the mechanical properties of zirconia ceramics under one-dimensional impact load were analyzed.Based on the basic theory of damage mechanics and the elastic brittleness damage model,the damage variables were defined,and the brittle damage constitutive model of zirconia ceramics under one-dimensional impact load was established.The constitutive relation of elastic brittle damage was determined according to the SHPB experimental results.Secondly,based on the surface topography detection of the grinding wheel,the truncated octahedron similar to the actual abrasive grain was used to simulate the shape of the abrasive,and the local grinding wheel simulation model in which the position and attitude of the abrasive are randomly distributed was established.The constitutive model of the workpiece material was customized by combining the dynamic mechanical properties and the true stress-strain curve of the zirconia ceramic.The force and heat coupling effects in the grinding process were comprehensively considered,to simulate the precision grinding process of zirconia ceramics under the coupling of force and heat,and the influence law of process parameters on the grinding damage was studied.By comparing the damage depth under the action of asingle force and the damage depth under the coupling of force and heat,the influence of the coupling effect of force and temperature on the grinding damage was investigate.Finally,the surface grinding experiment and the damage detection experiment were developed to detect and analyze the grinding force,grinding temperature,surface topography and subsurface damage depth of the workpiece,and the correctness was verified by comparing the experimental results with the simulation results.Based on the surface topography of the workpiece and the subsurface damage detection of the workpiece,the removal mechanism and damage mechanism of the zirconia ceramic material were analyzed.