| With the advancement of technology,the rapid development of space astronomical optics,satellite remote sensing technology and large-scale ground-based optical syst ems imposes strict requirements on the performance parameters of quality,r esolution ratio,stability,surface roughness and so on about optical system workpiece,especially for workpiece surface roughness,whi ch should reach at the level of ultra-smooth.However,it is di ffi cult to ensure the processing effici ency,precision and surface quality at the same time by the traditional polishing method,which will inevitably cause work damage to the surface of workpiece.Therefore,scholars of the world's optical manufacturing are committed to studying the processi ng mechanism and craf tsmanship of ultra-smooth surfaces in order to achieve ultra-smooth surface processing with higher precision and efficiency.In this paper,Ultraviolet-induced nanoparticle colloidal jet polishing technology is adopted,which i s expected to obtain a convenient,efficient,and green ultra-smooth surface processing met hod.And it can also process complex curved surfaces to meet the requirements of ultra-smooth surfaces.In the first place,T his paper analyzed the theoretical basis of achieving Ultraviolet-indu ced nanoparticle colloids and characteristics of jet flow in detail.Besides,the flow fi eld structure of one-shaped nozzles and cosine nozzles under non-submerged conditions i s also studied.Based on this,it analyzed the theory of photo-liquid coupled micro-jet.Nanoparticle colloids interact with the surface of the workpiece and the reactants will leave the surface of the space under the continuous impact of the jet.One part ofthe ultraviolet light is absorbed by the nanoparticles and another acts on th e surface of the workpiece as the photocatalytic effect of Interface Chemical Reaction,whi ch can accelerate the interface chemical reaction.T he finite volume method was used to establish the mathematical model of the optical-liquid coupled micro-j et flow field,whi ch was regarded as the theoretical foundation for the following numerical calculation and experimental analysis of the flow field.Secondly,T he two models of light-liquid coupled nozzl es adopted the Fluent soft ware to simulate the internal an d external flow fiel ds for common one-shaped nozzles and cosine nozzles under non-submerged conditions,and concludes a conclusion about Internal and external flow field,velocity and pressure of the surface and turbulence intensity of the two opti cal-liquid coupling nozzles under the same conditions.T he di stribution of velocity and pressure at the surface of the workpiece is discussed in detail.By analyzing the results of the numerical simulations of the external and internal flow fields of two kinds of light-liquid coupling nozzles,the di fferent characteristics of the flow field of t he cone-shaped nozzle and the cosi ne nozzle are compared to provide a theoretical basis for designing and selecting an appropriate light-liquid coupling jet nozzle.Once more,T he influence of the transition length of the cosine nozzle and the variation of the shrinkage angle on the flow field was analyzed.T hen the Taguchi method and the Minitab quality management statistics soft ware were used to optimize the four nozzl e parameters affecting the flow field.As a result,it gets reasonable structural parameters of Coupling nozzle coherence nozzle and makes a simulation and verification about the reality of flow field.Finally,According to the processing characteristics of Ultr aviolet-induced nanoparticle colloidal jets,a Ultraviolet-induced nanoparticle colloidal jet processing system was designed and constructed to perform a preliminary polishing test on monocrystalline silicon workpieces by using a self-configured Ti O2nanoparticle colloidal polishing solution.T he better quality of wor kpiece surface verified the feasibility Ultraviolet-induced nanoparticle colloidal jet machining of an ultra-smooth surface. |
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