Kinematic Simulation And Optimization In Deli-Quescent Polishing Of KDP Crystals

Potassium dihydrogen phosphate（KDP）crystal is a nonlinear optical material with excellent performance and is the only material that can be used to make frequency converters in ICF.It is known as one of the materials most difficult to process in the world because it is soft,fragile and deliquescent.And KDP crystals need to meet strict processing requirements such as large size,extremely low surface roughness,and excellent flatness if they are to be used in ICF.Therefore,the components with large sizes and high quality made of KDP crystals are the keys to the success of ICF and other projects.In order to meet the development needs of ultraprecision machining technologies for KDP crystals,in this dissertation,the kinematic simulation and optimization of the deliquescent polishing process of KDP crystals are presented.The main aspects of the research include:Firstly,the kinematic analysis of the deliquescent polishing process of KDP crystals was carried out,the kinematic and mathematical models of the deliquescent polishing process of KDP crystals were established,and the kinematic equations,the velocity expression and the polishing distance expression of a point on the polishing surface of the KDP crystals relative to the polishing pad were obtained.Then,the tracks and the velocity curves of a point on the polishing surface of the KDP crystal relative to the polishing pad when the horizontal distance from a point on the polishing surface of KDP crystal to the center of the sample holder,the rotation number of the polishing pad,the rotation number of the sample holder,the horizontal distance between the center of the sample holder and the center of the polishing pad,and the oscillation period took different values,were drawn.The polishing distances of a point on the surface of the KDP crystal relative to the polishing pad when the above parameters took different values are calculated and the polishing distance curves were drawn,and the effects of these parameters on the track,the relative velocity and the polishing distance are obtained,and the optimization directions of these parameters are determined accordingly.Finally,the comparing tracks,the relative velocity comparing curves and the polishing distance comparing curves of a point on the polishing surface of the KDP crystal relative to the polishing pad in the sample holder oscillation mode and the sample holder non-oscillation mode were drawn.The effect of polishing mode on the deliquescent polishing process of KDP crystals is obtained,and the better of the two polishing modes is determined accordingly.