Modeling And Experimental Study Of Monocrystalline Silicon Chemical-mechanical Micro-grinding Single-grain Grinding Force

The micro-grinding process has obvious advantages in processing complex and small parts of hard and brittle materials such as monocrystalline silicon,but the traditional micro-grinding process is difficult to meet the high-precision machining requirements of such parts,and the micro-grinding head wears seriously.To this end,the project team proposed a chemical-mechanical micro-grinding process.After softening the surface of the workpiece with a chemical modification fluid,then removed by grinding with a micro-grinding tool.The processing quality and the service life of the microgrinding head were improved.However,this process is still in the development stage.The mechanism of action of abrasive particles,the mechanism of material removal,especially the mechanical model of the action of abrasive particles in the modifiedsubstrate composite layer after the surface modification of the workpiece needs to be studied and clarified,so as to realize the realization of this process.Provide theoretical guidance and technical support for ultra-low damage machining of hard and brittle materials.This paper mainly carries out the following work:(1)The modification and removal process of the material in the chemicalmechanical micro-grinding process of monocrystalline silicon was analyzed,and the elemental composition of the modified layer was tested,so as to clarify the chemical modification reaction and the performance of the modified layer.The theoretical model of monocrystalline silicon surface modification-substrate composite layer in twodimensional coordinate system and three-dimensional coordinate system is studied and established,and the general solution of the model is obtained by analysis.(2)The mechanical model in the two-dimensional coordinate system of the monocrystalline silicon surface modification-substrate composite layer is derived,and the interface stress distribution map at the material interface and the contour map of the stress component inside the material are drawn using the mechanical model.By analyzing the interface,the stress distribution map and the stress component contour map can know the overall stress state inside the material,so as to adjust the processing parameters of the chemical-mechanical micro-grinding process.(3)The mechanical model in the three-dimensional coordinate system of the monocrystalline silicon surface modification-substrate composite layer was deduced,and the interface stress distribution map at the material interface and the stress component contour map inside the material were drawn using the mechanical model.By analyzing the interface,the stress distribution map and the stress component contour map can know the internal stress distribution of the material.Combine the mechanical model with the force distribution function of different single abrasive particles,and draw the stress component contour lines when different shapes of abrasive particles exert loads on the material.picture.By analyzing the contour maps of the two stress components,a more targeted machining plan can be formulated.(4)The nanoindenter was used to carry out loading experiments on the surface of monocrystalline silicon surface modification-substrate composite layer materials,and Raman spectroscopy was used to test the types of monocrystalline silicon phase transitions at the indentation point and the selected scratch point.The stress values required for the crystalline silicon phase transition are compared to prove the correctness of the model.Measure the thickness of the material modification layer.The experiment of using chemical mechanical micro-grinding to process single crystal silicon is designed,which proves that the processing quality of chemical mechanical micro-grinding process is better than that of traditional grinding process,and the effects of spindle speed,feed rate and grinding depth on the processing of monocrystalline silicon are analyzed.impact on quality.