【作者】 张少婧；

【导师】 胡小唐； 房丰洲；

【作者基本信息】 天津大学 ， 测试计量技术及仪器， 2009， 博士

【摘要】 随着制造业向微型化发展的趋势,微小型系统、精密装备仪器装置、微小型结构件等的需求日益迫切,对相应的加工技术提出了更高的要求。微细切削是一种适应多种材料微小型零件或结构精密加工需求的微细加工技术,而微细切削刀具作为发展微细切削加工技术的重要基础技术,其制备方法一直是制约微细切削技术发展的关键技术之一,特别是具有微米级特征尺寸,纳米级锋锐刃口及复杂形状微刀具的制备更是其中的难点。本文针对相应的微细切削加工需求和存在的问题,研究了基于聚焦离子束(FIB)铣削技术制备微细切削刀具的方法,并对加工工艺、刃口测量、实际应用等关键技术开展了系统的研究,解决了微刀具制造中的难点,提高了我国工具行业对微细切削刀具的自主开发能力。本文首先搭建了基于FIB技术制备微刀具的系统平台,将聚焦离子束/扫描电子显微镜(FIB/SEM)双束系统与样品旋转器相结合,精确控制了刀具相对离子束的方位,解决了微刀具制备中多自由度加工和高精度定位的技术瓶颈。提出了基于FIB铣削技术制备微刀具的加工方法,优化了制备流程及加工工艺,获得了具有纳米级锋锐刃口、高精度特征尺寸以及各种复杂形状的微刀具。研究了微刀具的超精密切削性能,分析了硬质合金(WC)、立方氮化硼(CBN)、聚晶金刚石(PCD)以及单晶金刚石(SCD)等典型材料的切槽微刀具在不同的切削参数下对加工结果的影响。研究了利用扫描电子显微镜(SEM)和原子力显微镜(AFM)测量微刀具刃口半径的方法,利用FIB修整AFM探针的方法实现了微刀具刃口轮廓的高精度测量,并对测量结果进行了最小二乘拟合以及探针展宽效应的修正,获得了刃口半径小于30nm的测量及评定方法。将FIB制备的微刀具应用于微光学元件及其模具的开发中,根据光学元件的加工需求进行微刀具的设计,采用FIB制备的微刀具实现了衍射微光学元件、菲涅耳反射镜、正弦调制模板等微光学元件的超精密车削加工,为微光学元件的制造开辟了新的途径。更多还原

【Abstract】 Recently, because of the miniaturization tendency of manufacturing, the needs for micro-systems, precision devices and equipment and miniature three-dimensional structures become increasingly urgent, and corresponding machining technologies have higher demands. Micro-cutting is a micrometer-nanometer machining technology that adapts to processing demand of microminiature parts or structures with a variety of materials. Micro-cutting tools technology is important basis of developing micro-machining. Continuously, its preparation method is one of key technologies limiting the development of micrometer-nanometer machining, and it is especially difficult for the preparation for micro-tools with micron feature sizes, nano-scale sharp cutting edge and complicated shapes. For the demands and existing problems of micro-machining, a novel method of micro-tools preparation using focused ion beam (FIB) milling was presented, and study on the key technologies such as machining technique, practical applications, measurement for cutting edge radius of micro-tools have been carried out systematically. As a result, some of the difficulties in micro-cutting tools manufacturing were solved and the ability to develop independently for tool industry in China was improved.Firstly, the system platform of micro-tools preparation by FIB technology was set up, which combines FIB/SEM dual-beam system with a sample rotation axis. Based on the system, the relative orientation of micro-tools and focused ion beam was controlled precisely so that the technical bottleneck was resolved for machining of multi-degree of freedom and high-precision position.Then, the machining method by FIB milling was presented for micro-tools preparation. The preparation processes and processing technology were optimized and thus micro-tools were obtained with nano-scale sharp cutting edge profile, high-precision feather sizes and various shapes. Ultra-precision cutting performances of the FIB-fabricated micro-tools were evaluated by analyzing micro-grooving tools of typical materials, such as tungsten carbide (WC), cubic boron nitride (CBN), polycrystalline diamond (PCD) and single-crystal diamond (SCD), impact on processing results with different cutting parameters.The measuring methods of micro-tools cutting edge radius of curvature were studied respectively utilizing scanning electron microscope (SEM) and atomic force microscope (AFM). High-precision measurement of cutting edge profile was achieved by using FIB-tailoring AFM probe. Moreover, measuring results were assessed by least-squares fitting and elimination of probe broadening-effect. Thereby, measurement and evaluation method of tools cutting edge radii of curvature of less than 30 nanometers was acquired.Finally, FIB-fabricated tools were applied for the development of micro-optical components and corresponding moulds. The micro-tools were firstly designed and fabricated by FIB according to demands of micro-optical components processing, and then they were used for ultra-precision turning of diffractive micro-optical elements, Fresnel reflectors, sinusoidal modulation template, etc. This opened new avenue for micro-optical components manufacturing.更多还原