基于合成双射流多场协同掺混增强的超光滑表面弹性域加工机理与方法

弹性域材料去除方式可有效避免传统机械加工方式带来的划痕、残余应力、塑性流变层等表面/亚表面损伤，弹性域内依靠界面化学吸附作用实现原子级材料去除，可获得原子级精度的超光滑表面，弹性域加工在高精度反/透射等光学元件加工都具有很好的应用前景。针对目前弹性域加工实现手段复杂、装置精度过高等问题，基于课题组发明的高性能合成双射流作动器提出合成射流弹性域超光滑表面加工方法。利用合成双射流作动器产生的两股反相射流合成一股稳定的主射流，开展喷射系统一体化设计，研制弹性域加工样机。基于数值仿真和流场显示技术分析主流的流场特性，揭示其卷吸和掺混作用机理以及时空演变发展过程。通过机理分析和定点抛光实验建立其材料弹性域去除的三维模型，分析影响去除效率和加工质量的主要因素，优化工艺参数。将新加工方法引入到现代光学系统光学元件超光滑加工工艺中，优化加工路径提高效率及精度，为弹性域加工方法推广应用提供有力的技术支撑。

Material removal taken place in elastic mode can effectively avoid the occurrence of surface/subsurface damages such as scratches, residual stress, plastic rheological layer， which are caused in the traditional mechanical machining method. Atomic level material removal rate can be realized depending on the chemical adsorption between the nano-particle and the workpiece surface, and the precision of processed ultra-smooth surface can reach to atomic level. It has a good application prospect in the fabrication of modern high precision optical element in elastic mode such as reflective and transmissive optical elements. Aiming at the problems of complex implementation methods and high device precision in the current elastic domain processing, an elastic synthetic jet ultra-smooth surface fabrication method is proposed based on the high-performance double synthetic jet actuator that has been invented by the research group. A stable mainstream flow is synthesized by two reverse jets generated by the double synthetic jet actuator, and the integrated design of the injection system is carried out accordingly. And then the original polishing prototype is fabricated. Based on numerical simulation and flow field display technology, the characteristic of the mainstream flow is analyzed. It is revealed the mechanism of the entrainment, blending and space-time evolution during the jet development process. Three-dimensional material removal model is established based on mechanism analysis and fix-point polishing experiments, and main process affecting factors are analyzed to optimize the process parameters. The elastic synthetic polishing method is introduced into traditional processing technology of typical high-precision optical component. Its excellent ultra-smooth performance capability is verified by optimizing the process route for different process requirements. It will provide effective technical support for the popularization of elastic domain processing method.