Experimental study on high-efficiency polishing for potassium dihydrogen phosphate (KDP) crystal by using two-phase air-water fluid

作     者：Ziyuan LIU Hang GAO Dongming GUO Ziyuan LIU;Hang GAO;Dongming GUO

作者机构：Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of EducationDalian University of TechnologyDalian 116024China 

出 版 物：《Frontiers of Mechanical Engineering》 (机械工程前沿（英文版）)

年 卷 期：2020年第15卷第2期

页      面：294-302页

核心收录：

学科分类：08[工学] 0802[工学-机械工程] 080201[工学-机械制造及其自动化] 0801[工学-力学（可授工学、理学学位）] 

基　　金：The authors would like to appreciate the financial support from the National Natural Science Foundation of China(Grant Nos.51135002 and 51621064). 

主　　题：potassium dihydrogen phosphate(KDP)crystal controllable deliquescence two-phase air–water fluid high-efficiency polishing material removal 

摘      要：A high-efficiency polishing approach using two-phase air–water fluid(TAWF)is proposed to avoid surface contamination and solve the inefficiency of previous water-dissolution polishing techniques for potassium dihydrogen phosphate(KDP)crystal.In the proposed method,controllable deliquescence is implemented without any chemical impurity.The product of deliquescence is then removed by a polishing pad to achieve surface planarization.The mechanism underlying TAWF polishing is analyzed,a special device is built to polish the KDP crystal,and the effect of relative humidity(RH)on polishing performance is studied.The relationship between key parameters of polishing and surface planarization is also investigated.Results show that the polishing performance is improved with increasing RH.However,precisely controlling the RH is extremely difficult during TAWF polishing.Controllable deliquescence can easily be disrupted once the RH fluctuates,which therefore needs to be restricted to a low level to avoid its influence on deliquescence rate.The material removal of TAWF polishing is mainly attributed to the synergistic effect of deliquescence and the polishing pad.Excessive polishing pressure and revolution rate remarkably reduce the life of the polishing pad and the surface quality of the KDP crystal.TAWF polishing using IC-1000 and TEC-168S increase the machining efficiency by 150%,and a smooth surface with a root mean square surface roughness of 5.5 nm is obtained.