Simulation Study On Damage Mechanism Of Sub Surface Cracks In High Speed Abrasive Belt Grinding Of Optical Materials

Brittle materials such as Silicon Carbide and K9 Optical Glass have excellent physical and mechanical characteristics such as high strength,high hardness,and corrosion resistance,which are widely used in aerospace,medical treatment,laser and other fields.However,during the grinding the surface of brittle materials,the surface of the workpiece will cause Surface Damage and Subsurface Damage,which reduces the quality of the surface / subsurface.At the moment,the mechanism of high-speed grinding of hard and brittle material belts at home and abroad is not deep enough.Based on ABAQUS finite element modeling of two-dimensional single particle grinding damage model,in order that study the influence of grinding parameters(grinding positive pressure Fn,grinding speed Vs and abrasive tip angle 2?)on grinding force and surface/subsurface damage.Built based on sharpness Non-linear relationship between subsurface crack depth and surface roughness scored by abrasive grains and microspherical abrasive grains Model to analyze the influence of material removal and surface roughness on subsurface damage.A model based on the nonlinear relationship between the depth of subsurface cracks and surface roughness based on sharp abrasive particles and tiny spherical abrasive particles was established to analyze the effects of material removal and surface roughness on subsurface damage.The results of this study show that:(1)Based on the ABAQUS finite element grinding damage simulation model,in the initial stage of single-grain grinding,cracks start to form in front of and below the abrasive grains.As the abrasive grains continue to move toward the grinding direction,the cracks in front of the abrasive grains are removed by the abrasive grains,but the cracks under the abrasive grains eventually remain on the workpiece surface,forming surface and subsurface defects.When the grinding positive pressure Fn and the abrasive tip angle increase,the grinding force also increases and the subsurface damage has a tendency to deepen,and when the grinding speed Vs increases,the grinding force and the subsurface damage depth decreas.(2)Based on MATLAB simulation analysis of the two-dimensional surface morphology of the workpiece after grinding,the material removal volume and materialremoval rate of single-grain grinding of brittle materials all follow the grinding positive pressure Fn and the top of the abrasive particles The angle 2? increases.The increase of grinding speed Vs decreases the material removal volume,and the material removal rate increases with the increase of the grinding speed,indicating that a higher grinding speed is beneficial to improve the material on the surface of the brittle material Removal rate.When the grinding speed reaches a certain speed value,increasing the grinding speed does not significantly help to increase the material removal rate.(3)Establish a nonlinear relationship model between subsurface crack depth and surface roughness based on sharp abrasive grains and tiny spherical abrasive grains,workpiece material surface roughness and subsurface damage depth shows a nonlinear monotonous increasing relationship.