Study On The Performance Of Sandwich Elastic Grinding Wheel To Achieve Mirror Surface

A novel elastic grinding tool with sandwich structure is proposed in the present work to meet the high-efficiency manufacturing requirements of mirror surface for ultra-precision parts used in advanced optics and biomedical fields.The mechanism and process of grinding high-performance S136 mold steel were systematically studied.Main research works are as follows:Structure of the sandwich elastic grinding wheel is designed.The tool adopts three layers structure,including grinding wheel body,elastic layer and abrasive layer,by adding an elastic layer between the body and the abrasive layer to simultaneously ensure the abrasive particle holding properties of the abrasive layer and the required elasticity of the tool.In addition,the physical properties and performance of the main structural components are analyzed.Contact mechanism between the tool and workpiece has been invest igated based on the theoretical analysis,simulation and experimental verification,and the grinding wheel structure is optimized accordingly.Grinding principle and machining surface generation principle of the sandwich elastic grinding wheel is analyzed.Grinding wheel dressing,tool setting and cooling methods are tested and the applicable methods are proposed.Grinding tests on S136 mould steel are conducted.Effects of process parameters on surface roughness and material removal rate are investigated.The experimental results show that the material removal rate is positively correlated with the grinding wheel speed,the theoretical grinding depth and abrasive particle size are negatively correlated with the feed rate and path spacing;The surface roughn ess is positively correlated with the grinding wheel speed,theoretical grinding depth and abrasive particle size,whilst the feed rate has little effect on the roughness.There is an optimal path spacing,increase or decrease of path spacing from this value would cause the increase of roughness.The general relationship between the actual removal depth and the surface roughness is explored in a certain grinding sample.The results show that the surface roughness increases with the increase of the actual re moval depth.That is,lower surface roughness can be achieved when the original grinding morphology on the workpiece is just removed.The S136 mold steel is subjected to a comprehensive domain mirror grinding test.The surface roughness was converged from Ra 142 nm to Ra 7.427 nm in one grinding step,achieving mirror surface finish and high material removal rate.The test results prove that the sandwich elastic grinding wheel tool can be effectively applied to the high-efficiency mirror grinding of ultra-precision parts.