Study On Single Crystal Germanium Solid-liquid Two-phase Flow Grinding Polishing Simulation And Experiment

Single crystal germanium has good chemical and physical properties,which makes it widely used in various fields.With the development of related fields and technology,the requirements of single crystal germanium's processing efficiency,surface precision,surface and residual stress demand higher requirements.To solve the problems above,single crystal germanium grinding polishing technology has been developed,it is the key points that many scholars both home and board to improve the removal rate and surface quality of single crystal germanium,meanwhile,there needs further study on the mechanism of material removal in the process of polishing.For that,the effect of solid liquid two phases flow on the material removal rate and surface quality in the process of polishing were analyzed in this paper based on the non-contact model theory,the experiment terrace was built to carry out related experiments.The main research contents are as follows:Frist,according to the material remote and impact abrasion theory,the single grain impact simulation model was built based on ABAQUS finite element simulation software,to analysis the influence of impact velocity,impact angle,grain size,grain material and other factors on the impact deformation of single crystal germanium.A multi-grains impact model was built,two factors of grain particle size and grain material could be controlled during the experiment were simulated and the surface deformation area and residual stress of the material after impact were analyzed.According to the analysis,the size of grains should be considered first,then the materials and modulus of elasticity should be chosen by requirements.Second,according to the two-phrase flow theory,grain motion theory and other mathematical models,a solid-liquid two-flow polishing model was built based on the movement and position connection of actual polishing process between carrier plate,test-piece,polishing liquid and polishing pad.The impact of the polishing fluid,grain size and grain material three influence factors on the edge over abrasion of work piece were simulated and analyzed,respectively.By analysis,in order to ensure the speed of processing,a larger size and high density grain can be chosen.Meanwhile,a solid-liquid two-flow polishing experiment and exam system was built,the system is consisted of equipment and goods below: Auxiliary device(heating platform,drop feeder),UNIOPL-1200 S automatic pressure abrasive finishing machine,experimental materials(polishing liquid,polishing pad),exam device(electronic balance,roughness measuring instrument,high resolution diffraction),the solid-liquid two-phrase polishing experiments of single crystal germanium were carried out.Finally,based on the theoretical analysis and simulation,the single crystal germanium polishing experiments were carried out by the established experimental system.By using single factor experiment to study the influences of grain size and grain material on surface's material removal rate of solid-liquid two-phrase polishing,surface roughness and residual stress.To prove the effectiveness of simulation by experiments,which provide a theoretical guidance for improve the technics of solid-liquid two-phrase high precision polishing.By using 0.1?m grain can get good surface quality,which proves the effectiveness of simulation.