基于主动调制车削的硬脆材料微结构曲面延性域加工方法研究

Machining of micro-structured surfaces on hard/brittle materials is difficult due to the complexity of the surface and the machinability of the material. In this project, a new processing technique named active-modulated turning (AMT) is proposed to realize ductile machining of micro-structured surfaces on hard/brittle materials. The proposed processing technique will be studied from the perspectives of the machining mechanism, prediction of machining quality, machining technique etc. The main scientific problems of this research are the interactive mechanism between the diamond tool and hard/brittle materials and its influence on the formation of the micro-structured surface, and the influence of the modulation method on the ductile machining of micro-structured surfaces on hard/brittle materials. Guided by these problems, the removal mechanism of the hard/brittle material considering the varied influential parameters will be studied to reveal the relationship between the tool-material interactive mechanism and the machined surface, to establish models for the critical depth-of-cut (DOC) and fracture, and to determine the modulation method which is able to effectively increase the critical DOC. Furthermore, a model for the machining of micro-structured surfaces on hard/brittle materials with varied influential parameters will be built for developing a machining simulation system to simulate the machining process, predict the machining quality and optimize the machining parameters. Based on the effective modulation method, a new AMT machining system will be developed to verify the proposed principles, methods and techniques. In summary, the research in this proposal will provide us the theoretical basis and an implementation technique for the ductile machining of micro-structured surfaces on hard/brittle material using AMT.

针对在硬脆材料上加工微结构曲面存在的表面复杂性和材料难加工性双重难题，本项目提出采用主动调制车削加工方法实现硬脆材料微结构曲面的延性域加工。针对该加工方法，从加工机理、加工质量预测和加工技术等角度，以变作用参数下金刚石刀具与硬脆材料的交互作用机理及对微结构曲面创成质量的影响、主动调制模式对硬脆材料微结构曲面延性域加工的影响等关键科学问题为导向，研究变作用参数下硬脆材料的去除机制，揭示各作用参数与材料去除方式和表面加工质量的内在联系，构建与作用参数相关的临界加工尺度和裂纹模型，确定能有效提高临界加工尺度的主动调制模式，建立变作用参数下硬脆材料微结构曲面的加工模型并据此开发加工仿真系统模拟加工过程、预测加工质量和优化加工参数，并以有效主动调制模式为导引，开发新型主动调制车削加工系统验证所提原理、方法和技术。研究成果可为基于主动调制车削的硬脆材料微结构曲面延性域加工提供一种理论依据和实施技术。

在硬脆材料上加工出具有微结构表面的光学元器件因其显著的优点，在国防工业、航空航天和光电通信等领域的应用需求日益增长，但其加工面临材料难切削加工和加工表面复杂双重难题。因此，本项目提出了一种主动调制车削加工脆性材料方法并对其进行了系统研究，以实现硬脆材料微结构曲面的延性域加工。主要研究进展如下：（1）分析了加工微结构曲面时加工参数动态变化条件下材料去除形貌变化，并对脆性材料切削加工过程中的切削力进行数学建模；（2）研制了一种基于超声椭圆振动切削的椭圆轨迹可控的主动调制切削系统，该系统能够有效在硬脆材料上加工出微结构表面，提高了加工效率和加工表面质量；（3）建立了该系统切削加工过程的加工模型，揭示了脆性材料临界切削深度的本质原因，提出了该方法的临界切削深度预测模型，为提高脆性材料加工效率提供了理论依据；（4）建立了针对该系统的刀尖圆弧半径补偿算法以及椭圆轨迹补偿算法，避免了刀具与工件之间发生“过切”或“未切”现象，提高了实际加工微结构形状精度。本项目的研究成果可为脆性材料微结构曲面加工技术所面临的难点提供一种解决方案，对促进包括面向国防工业以及消费者需求等领域的广泛应用具有重要的意义。