Numerical And Experimental Research On Double-grains Grinding Silicon Carbide Ceramics

There has been the widespread application of SiC ceramics in aeronautics and astronautics due to its unique physical and mechanical properties.In recent years,the rapid development of aeronautics and astronautics filed puts forward higher requirements for the machined form accuracy and surface integrity.The way of optimizing grinding wheel topography and grinding process to improve machined surface quality and efficiency becomes especially important.At present,a single-grain grinding method is widely used in the research on SiC grinding mechanism,because the maximum undeformed chip thickness(M-UCT)can be controlled conveniently and the process of grinding is independent of other grains.However,a large number of grains on the grinding wheel surface take part in the grinding process synchronously and the single-grit grinding method can not exactly explain the materials removal mechanism in contact regions.In the present paper,a double-grains grinding method is applied to study the coupling interaction among grains during SiC ceramics removal process.Based on the numerical and experimental results,the critical axial distance is achieved at the maximum coupling interaction.Then,the effect of grinding parameters on the grinding process of SiC is investigated.The main research work and conclusions are as follows:(1)Simulate the grinding process of SiC ceramics based on the double-grains grinding method.The first principal stress and grinding topography were analyzed at different axial distances.In the view of the effect of the axial distance on the grinding force and material removal rate,the critical axial distance of the maximum coupling interaction is approximately determined at 300?m at the point of maximum interference.(2)Explore basic distribution form of grains based on monolayer brazed wheel.Conduct the experiment of axial distance.Put forward that the optimized axial distance is 309?m when using #35/40 diamond grits,and the main evaluating indicators are grinding force and material removal rate.The grinding topography is not bad.(3)Study the effects of the maximum undeformed chip thickness and grinding depth and grinding speed on coupling interaction.It shows that large M-UCT,great grinding depth and high grinding speed are benifical for high efficiency maching of SiC ceramics.However,when M-UCT exceeds 0.3?m,the grinding surface gets rough.Graet ginding depth results in large grinding force.In addition,the ductile materials removal mode becomes dominating when grinding wheel speed is more than 80m/s.