基于SPM的纳米加工技术研究

扫描探针显微镜（SPM）纳米加工技术是当前非常活跃的纳米加工研究领域,其研究成果有可能成为微纳米器件制作的主要方法。论文主要介绍了单原子操纵、阳极氧化法,以及机械刻蚀加工等SPM纳米加工方法的机理、特点及研究进展动向。     

基于SPM的纳米加工技术研究

扫描探针显微镜(SPM)纳米加工技术是当前非常活跃的纳米加工研究领域,其研究成果有可能成为微纳米器件制作的主要方法。论文主要介绍了单原子操纵、阳极氧化法,以及机械刻蚀加工等SPM纳米加工方法的机理、特点及研究进展动向。     

基于电化学加工方法的铝基超疏水表面制备技术研究

鉴于金属铝表面存在微米级的晶界和纳米级的位错,在外加电场和电解液的作用下,晶界位错处因具有更高的位能会使得阳极优先溶解,进而形成微纳米结构相结合的粗糙表面,提出一种新的铝基超疏水表面的电化学制备方法,实验研究了其加工质量、加工效率和加工条件之间的关系,结果显示电化学加工方法能够在铝基底上制备出多阶层微/纳米结构,可用作超疏水表面基底。电化学加工比化学刻蚀法有更好的可控性,同时比光刻等方法更经济。所加工表面经过低表面能材料修饰后呈现超疏水的特性,与水滴的接触角达到167°,滚动角小于3°。     

外加电压对AFM阳极氧化加工的作用机理

利用原子力显微镜AFM进行阳极氧化纳米刻蚀加工的实质是电场作用下发生的电化学反应,外加电压是影响氧化加工的最重要的因素。在氧化加工过程中,外加电压存在着阈值。分析了电压的大小、类型对氧化物的结构和生长速率产生的具体影响,偏压的提高可以获得较厚的氧化物,氧化速率随氧化层厚度下降,而调节电压脉冲峰值、周期、频率可以增强氧化物的生长速率,提高氧化物的纵横比。说明通过控制电压可以控制实现对氧化过程的控制,而交流脉冲电压对阳极氧化加工最为有利。     

基于AFM纳米机械刻蚀的分子动力学模拟研究

基于原子力显微镜AFM(atomic force microscope)的纳米机械刻蚀加工是扫描探针刻蚀加工技术( scanning probe lithography, SPL)的一个重要组成,目前已取得较大进展.但由于纳米机械刻蚀涉及原子的结构与运动,其加工机理尚有待于进一步研究.分子动力学模拟技术是近年来发展的继实验和理论研究后的又一重要研究方法.文章综述采用分子动力学模拟技术,研究基于AFM的纳米机械刻蚀加工的进展, 分析纳米尺度的加工机理,评述探针、刻蚀工艺、工件材料等因素对纳米机械加工过程的影响.文章最后指出今后研究的方向.     

大气状态下STM电场加工机理分析

扫描探针显微镜（SPM）家族的拓展始于扫描隧道显微镜（STM）,它的发明使人类能够真正获得物质表面在原子尺度上的局域电子结构,并可揭示与之对应的原子结构,基于SPM的纳米加工技术同样是从STM开始的,本文主要介绍大气状态下STM在Au和Ti表面的电场加工结果,并对其作用机理进行较深入分析,确定表面结构的生成为准接触和电场诱导氧化的综合作用。     

各向异性湿法刻蚀中刻蚀温度对硅尖形貌的影响

纳米硅尖在原子力学显微镜、微机械电子、光学研究、纳米级图形加工上具有广泛的用途。然而,如何制备小曲率半径高纵横比的硅尖仍为有待解决的问题和挑战。根据各项异性湿法刻蚀硅尖原理,设计了硅尖的加工工艺流程,并制备出不同纵横比的纳米硅尖。通过观察掩模对角线刻蚀进程,得到了掩模对角线刻蚀速率与刻蚀温度的关系;对比了不同刻蚀温度对刻蚀硅尖的影响,发现采用40wt%KOH刻蚀液,水浴78℃的刻蚀条件满足自锐化且刻蚀出纳米硅尖曲率半径小而纵横比大,其曲率半径为26 nm,纵横比为1.9。     

动态电场诱导氧化实现纳米结构的加工

利用原子力显微镜 (AFM )进行表面的局部氧化加工是进行纳米结构加工的一种很有前途的方法。它具有广泛的应用范围 ,可以进行功能性纳米电子器件和纳米机械结构的加工。实验采用了动态电场作用下的AFM诱导氧化的方法 ,提高了氧化物的生长速度 ,并且改善了氧化结构的纵横比 ,能够更好地控制生成氧化物的结构和电属性。     

大气状态下SPM纳米加工系统的开发

对现有的商业化SPM进行了一些必要的改造，使其适合于扫描探针加工的要求。讨论了在DI公司多功能SPM基础上开发纳米加工系统的可能性，并提供了一套完整的信号施加，过程监测和环境控制的方法，实现了矢量式的纳米氧化加工，得取了30nm宽的氧化结构，为下一步进行纳米电子器件的构建奠定了基础。     

精密仪表用铝合金瓷质阳极氧化表面粘接性能研究

铝合金瓷质阳极氧化工艺是精密仪表制造中的一种特殊且关键的技术应用，但该氧化表面的胶粘连接常常出现脱粘、泄漏等失效问题。为此，通过探究瓷质阳极氧化表面的微纳形貌与润湿性特征以及高低温下的胶接强度与失效模式，并与自然氧化表面及磷酸阳极氧化表面进行对比分析，阐明瓷质阳极氧化表面胶接失效的影响机理。结果表明，磷酸阳极氧化虽未在微米尺度上显著改变表面粗糙度，但其纳米级多孔氧化膜结构，可显著提高表面润湿性与界面粘接作用力；而瓷质阳极氧化膜在50 000×的SEM形貌下较为致密、平滑，显示出不利于胶粘剂润湿与吸附的物理特征；在-30～80℃下，温度与氧化方法均对胶接强度影响显著，胶接强度随着温度的升高而降低；磷酸阳极氧化表面的强度最高(36.75～20.54 MPa)，其次为自然氧化，最差为瓷质阳极氧化(24.79～17.10 MPa)。热红外与能谱分析表明，瓷质阳极氧化表面的粘附强度低于胶粘剂的内聚强度，失效模式为粘附失效，而磷酸阳极氧化表面的失效模式为胶粘剂的内聚失效。因此，瓷质阳极氧化表面由于氧化膜的致密性，缺少类似磷酸阳极氧化膜的纳米级多孔结构，不利于表面润湿吸附，降低了胶粘剂与基底表面的机...     

纳米操作加工过程定位检测问题研究

微纳米操作、加工、检测和控制在各个领域获得广泛的研究和应用,在微纳米层次上进行原位、定位的操作、检测、加工是经常遇到的问题。扫描探针显微镜技术(Scanningprobemicroscope,SPM)提供强有力的工具,人们利用其不同类型的针尖与相应样品表面产生的化学或物理作用达到目的。但扫描探针显微镜针尖同时用于检测、加工和成像,会因为针尖磨损、状态的改变,影响检测信息的准确性、可靠性,直接影响结果的判定。本文提出一种在微操作加工过程的定位检测技术,即操作过程工具和探针承担不同任务,工具负责加工操作,探针用于检测并定位于操作加工位置,进行了实验并分析讨论定位过程相关问题。     

Design and development of PCD micro straight edge end mills for micro/nano machining of hard and brittle materials

One of the biggest challenges for mechanical micro/nano milling is the design and fabrication of high precision and high efficiency micro milling tools. Commercially available micro milling tools are either too expensive (around several hundred US dollars) or simply made from downsizing of macro milling tools, which is sometimes not appropriate for the specific micro/nano milling requirements. So the design and fabrication of custom micro milling tools are necessary. In this paper, a micro straight edge endmill (SEE) is designed. Static and dynamic FEM analyses have been done for the SEEs with different rake angles trying to identify their stiffness and natural frequencies. By wire electrical discharge machining (WEDM), the SEEs made of polycrystalline diamond (PCD) with three different rake angles have been fabricated. The evaluation milling on tungsten carbide (WC) and silicon wafer have processed on a nano milling center. Experimental results show the SEEs have a good ability to simultaneously micro/nano milling of both the side and bottom surfaces with submicron surface roughness, and the SEE has high accuracy for large aspect ratio thin wall machining. The milling experiments on silicon wafer have successfully demonstrated that ductile mode machining was achieved and the coolant played an important role in silicon wafer milling.     

Engineering surface and development of a new DNA micro array chip

This paper proposes a new concept of the ‘engineering surface’, which extends the conventional idea of a functional surface by combining it with micro/nano manufacturing technology. Characteristic features and possibilities of the engineering surface are discussed in detail. This paper reviews studies on micro/nano fabrication technologies for advanced materials and evaluation technology for surface function. New fabrication technologies, micro machining and nano forming, are introduced, which will be basic manufacturing processes of the engineering surface. Also, a new surface evaluation technique is introduced for the surface energy of the nano fabricated surface. Design of a new DNA micro array chip is introduced as an example of applications of the engineering surface. Controllability of surface property by nano fabrication is studied.     

A study on the micro tooling for micro/nano milling

Many researches have studied the micro tools either by simulations or experiments showing that the micro tools play very important roles in micro/nano machining, and micro tool geometries have a direct impact on the final machining quality. Commercially available micro milling tools are usually simply made from downsizing of macro milling tools, which may not be able to be accurately fabricated. Custom micro milling tools have been created by some researchers, but no design criteria for micro milling tools have been introduced. The above factors constrain the development of effective micro milling tools and consequently constrain the researches on micro/nano milling. Based on former researcher??s work, this paper tries to introduce the design criteria for the custom micro tooling. Firstly, the extent typical micro milling tools are studied, and their drawback/limitations are summarized. Secondly, experimental evaluations of the key drawback/limitations are processed. Thirdly, the design criteria for custom micro milling tools are proposed, and corresponding design process is introduced. Then, a new micro hexagonal end mill has been designed based on these criteria. Finally, a polycrystalline diamond micro hexagonal end mill with a diameter of 0.5?mm was fabricated by wire electrical discharge machining, and the evaluation experiments for the hexagonal end mill have been processed on a nano milling center. Experimental results show the newly designed hexagonal end mill can achieve submicron level surface roughness and has simultaneously high-accuracy side and bottom machining capabilities.     

SPM用于超精加工领域的重要性及特殊性

讨论了扫描针显微镜作为一种显微工具的优势和不足,介绍了把ＳＰＭ应用于超精密加工检测领域所要注意的问题,指出纳米级加工机理的研究将依赖于ＳＰＭ的复合化及多功能化,只有实现了加工与检测的一体化才能正确评价加工方法及工艺参数的优化选择,从而引导超精密加工的发展。     

国家基金委机械学科在微／内米技术领域资助项目概况

纳米技术是在近年来国际前沿研究领域，世界主要发达国家的政府均投入巨资加强该领域的研究或设立国家研究机构，以期望在纳米材料、纳米生物技术、微纳米加工技术及测量、信息技术和相关国防应用领域取得突破，并形成一个庞大的产业。本文概述了国家自然科学基金委员会机械学科在纳米技术领域中的资助情况，进行了一定的分析和总结，并指出了今后的发展趋势。     

Mechanism of Abrasive Wear in Nanomachining

In this study, nanomachining is utilized to investigate the abrasive wear mechanism that produces a nano scale groove on a bulk material. Two different tools (Berkovich and Conical) with the same tip radius (100 nm) but different edge geometries were used for machining both Cu- and Ni-coated materials with a nanoindenter that was equipped with a nano scratching attachment. It was found that the generated forces (normal and cutting) increased with the increase of depth of cut; however, the generated normal force at the minimum depth of cut (50 nm) was more than the critical force for all machining conditions. Therefore, at the minimum depth of cut, groove formation started with the ploughing mode of abrasive wear mechanism, then the cutting mechanism activated along with the ploughing mechanism above a 100 nm depth of cut. The percentage values of these two mechanisms were determined and utilized to determine the dominant mode of the abrasive wear mechanism for producing a nano scale groove on a metal surface and, to correlate this, abrasive wear mechanism with the co-efficient of friction (μ) at different machining conditions. The results also showed that the co-efficient of friction (μ) increased when ploughing was the dominant mode of abrasive wear mechanism to produce a nano scale groove. Thus, μ was found to be proportional to the ploughing mode of abrasive wear mechanism in nanomachining.     

Multi-scale surface simulation of the KDP crystal fly cutting machining

The paper presents a novel approach for the modeling and simulation of surface generation in the potassium dihydrogen phosphate (KDP) crystal fly cutting machining process in the macro, micro, and nano scales, in order for the evaluation specifications in different spatial frequency region. The main influential factors of surface topography in different scales are discussed and modeled by different methods. The simulations take into account all the intricate aspects of the machining process affecting the surface topography and texture formation such as the straightness of the slide, the dynamic performance of the machine tool, and the cutter profile. This method can realize the machine tool performance and machining parameter optimization by the surface prediction and detection. The numerical calculation (NC) and the finite element (FE) method are used in the macro and micro scales. Molecular dynamics (MD) simulation is used in the nano scale. Furthermore, the proposed systematic modeling approach is verified by cutting trials which provide the coincident results of the simulated surface topography.     

纳米切削实验研究

实现纳米科学技术的一个重要课题是纳米加技术的开发和应用,分析讨论目前广泛用于纳米测试中的扫描探针显微技术手段后,探讨直接内米切削的可能性和方法,并进行了实验研究。结果表明,开发的纳米切割方法毁可作为材料加工过程的研究手段,又具有很好的实实应用前景。