Large-Scale Metrology - An Update

Developments in large-scale engineering metrology since the 1978 report of Puttock are reviewed. Advances in optical technology and fast, low-cost computation have led to wide-spread use of laser trackers and digital photogrammetry for general-purpose coordinate metrology. Techniques for high-accuracy straightness measurement, precision leveling, and absolute distance metrology are described, together with approaches to compensation for the effects of atmospheric refraction. Methods for uncertainty evaluation are discussed and several illustrative examples are presented.     

Probing Systems in Dimensional Metrology

Dimensional parameters are the most commonly encountered quality characteristics of workpieces. The measuring process for testing conformance of those characteristics contains the important sub-process of probing the surface. A huge variety of probing systems for performing different measurement tasks on the shop floor, as well as in the metrological environment, have been developed. In coordinate measuring machines (CMM) probing systems must ensure reproducibility of the sensing operation even in the sub-micrometer range. This paper describes requirements, different principles and characteristics of tactile probing systems in dimensional metrology, with examples of several probing systems that are used in practice.     

Micro and Nano Machining by Electro-Physical and Chemical Processes

The need for micro-features, components and products is rapidly increasing in diverse industries such as electronics, medical and aviation. Product miniaturization demands innovative manufacturing methods. Various existing macro-manufacturing processes are being modified to perform micro-scale manufacturing. Electro-physical and chemical micromachining processes play important role in this field due to their special material removal mechanisms. This paper reports the worldwide technical developments and state-of-the-art of electro-physical and chemical micromachining processes. Issues related to the supporting technologies such as standardization, metrology and equipment design are briefly assessed. Non-technological issues including environmental effects and education are also discussed.     

Optical Methods for Dimensional Metrology in Production Engineering

Metrology in production engineering must be fast, accurate, robust and automated, and ideally integrated into the production line. In many respects, optical methods seem to fulfil these requirements. Although optical methods have a long tradition in dimensional metrology, the rapid progress in the development of optoelectronic components and availability of increased computational power makes many new technical approaches possible. This paper provides a technical overview of the optical methods available for dimensional metrology. Methods for the measurement of length, angle, surface form and spatial co-ordinates are described. The paper summarises both the metrological characteristics and the technical limitations of the methods. Furthermore, it presents some new and promising approaches that, in the future, may play an important role in dimensional metrology for production.     

Metrology of freeform shaped parts

The scope of this keynote paper is to present the state of the art in the metrology of freeform shapes with focus on the freeform capabilities of the most important measuring techniques and on related metrological issues. Some examples of products are presented, for which the metrology of freeform shapes is important to guarantee the desired functional performance of the product. A classification of freeform measuring tasks and the corresponding metrological requirements are presented. A review of the most important measuring techniques is presented along with their capabilities for freeform measuring tasks. Specification and verification of freeform surfaces, including data evaluation and comparison to specifications are discussed, along with the measurement uncertainty and traceability of freeform measurements.     

熔模铸件的尺寸稳定性和精度

客观地叙述了我国精铸件尺寸精度的现状以及与有关标准，国外水平的差距。较全面地阐述了影响熔模铸件尺寸稳定性的各种因素和铸件收缩率准确赋值的关键环节，并强调指出建立合理的尺寸测量系统的重要性。     

Nano Surface Engineering in the 21^st Century

Nano surface engineering is the new development of surface engineering, and is the typical representation that the advanced nano technology improves the traditional surface engineering. The connotation of nano surface engineering is profound. The initial stage of nano surface engineering is realized at present day. The key technologies of nano surface engineering are the support to the equipment remanufacturing. Today the relatively mature key technologies are: nano thermal spraying technology, nano electric-brush plating technology, nano self-repairing anti-friction technology and metal surface nanocrystallization, etc. Many scientific issues have been continuously discovered. Meanwhile they have been applied in the practice more and more, and have archived the excellent remanufacturing effect.     

Micro metal powder injection molding of W-Cu nanocomposite powder

Increasing attention is being paid to micro metal injection molding as a manufacturing technology for miniature part. W-Cu nanocomposites have been used as heat sink and packaging materials in microelectronic devices. A micro injection molding technique will provide and appropriate tool to fabricate W-Cu nanocomposite materials for microcomponents. In the present study, a fundamental investigation of micro metal injection molding using W-Cu nanocomposite powder is reported. The densification behavior of W-Cu nanocomposite was examined in order to confirm the shape stability of microcomponents.     

微型泳动机器人研究

介绍了国内外微型泳动机器人的研究进展,对微型泳动机器人的工作机理和存在的问题进行了分析,论述了医用领域微型泳动机器人的研究难点和关键技术,并对微型泳动机器人的发展趋势及应用前景进行了探讨。     

纳米TiO2在汽车面漆中的应用研究

阐述了纳米TiO2对汽车面漆性能的影响机理,提出了利用纳米TiO2提高汽车面漆耐老化性的设想,制定了纳米TiO2涂料的配方,并研究分析了纳米TiO2对汽车面漆性能的影响规律.通过实验对漆膜的光泽度、附着力、冲击强度、硬度、耐水性、耐老化性等进行检测,当纳米TiO2的加入量为1.0%～2.0%时,涂层的耐老化性能平均提高20%左右,其光泽度也有所提高,而附着力、冲击强度、硬度、耐水性提高不明显.     

Codeposition of micro- and nano-sized SiC particles in the nickel matrix composite coatings obtained by electroplating

Micro- and nano-sized SiC particles were codeposited with nickel by electrolytic plating from a nickel sulfamate bath and the effects of plating parameters such as pH of the plating bath, SiC content in the plating bath, and stirring speed on the deposition behaviors of Ni-SiC composite coating layers were studied. The result revealed that the micro-sized SiC particles are more negative than the nano-sized SiC particles in the Zeta potential. The codeposition of SiC can be increased by increasing the SiC content in the plating bath and the pH of the plating bath within the present experimental range. In case of micro-sized SiC particles, increasing stirring speed always lowered the codeposition of SiC. In case of nano-sized SiC particles, the codeposition of SiC showed a maximum at the stirring speed of 100 rpm. The nano-sized SiC particles are more difficult to codeposit than the micro-sized SiC particles and showed rougher plated surface compared with the micro-sized SiC particles, which may be attributable to the agglomeration of nano-sized SiC particles in the plating bath.     

纳米TiC涂层的制备技术研究

TiC涂层由于具备良好的性能而广泛地应用于机械加工行业.以高温CVD方法制备TiC涂层技术为基础,研究了在反应腔中设置温度达到1600℃的高温处理装置,使原料气经过高温处理装置后在基体上沉积出TiC涂层.经金相显微镜测量厚度约为10μm,经XRD检测成分为:界面出现脱碳相Co 6W 6C,膜层除含有少量氧化物杂质外,为纯净的TiC涂层,颗粒尺寸平均为84.8nm.探索了制备纳米TiC涂层工艺的机制,其中高温处理、大温度梯度、惰性气体及冷却腔体避免引入杂质是形成纳米TiC涂层的关键因素.制备纳米级TiC涂层,可使涂层硬度、断裂韧性、表面光洁度、耐高温性能等性能指标得到提高,提高了TiC涂层产品的综合性能.     

Microstructure and Behaviors of Nano Composite Coating

ELECTRO BRUSH PLATING is a traditionaltechnology in the field of surface engineering.Thisprocess has been widely used due to its advantagessuch as simplicity of equipment,various type ofcoatings,excellent adhesion between coating andmatrix,and so on.It is significantly used as mechanicalrepairing without departing or rushing to repair in openregion.Nano particles result to surface effect,smallsize effect,and other effects since its size of is less than100nm.So they are used in surface …     

一种微机器人驱动器的动力特性研究

针对采用微小弹性啮合轮传动机构研制的微驱动器进行了运动和动力学分析,建立了微驱动器的运动方程和动力学方程.然后采用微驱动器模型进行了运动实验和传动力特性实验,实验研究表明,微驱动器的运动状态受到工况条件、微传动机构的动力特性等因素的影响.     

Multisensor data fusion in dimensional metrology

Multisensor data fusion in dimensional metrology is used in order to get holistic, more accurate and reliable information about a workpiece based on several or multiple measurement values from one or more sensors. The theoretical background originates in classical mathematics and statistics, in methods of artificial intelligence (AI) and in the Bayesian fusion approach. Sensor technologies and sensor characteristics influence the data fusion process and determine the gain of information compared to the application of a single sensor. Homogeneous and inhomogeneous sensor configurations lead to complementary, competitive and cooperative information integration with specific advantages depending on the application. The scope includes image fusion, tactile and optical coordinate metrology, coherent and incoherent optical measuring techniques, computed tomography as well as scanning probe microscopes.     

微型爬壁机器人研究的关键技术

首先论述了微型爬壁机器人的发展背景及与传统爬壁机器人的区别。然后对微型爬壁机器人研究的国内外现状及关键技术做了详细分析。     

Micro Engineering

The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products. The implications of the decisions in the design phase on the subsequent manufacturing processes are considered vital. Finally, manufacturing and assembly of micro products as well as the philosophy of micro factories are presented and discussed.     

Study on Factors Determining Limits of Minimum Machinable Size in Micro EDM

This paper describes an investigation on factors determining the limits of the minimum machinable diameter of micro rods obtained by micro EDM. Possible factors which influence the limits are discharge crater size, depth of heat affected zone, residual stress, and material micro-structure. In this paper, the influences of residual stress and material micro-structure were especially examined. For the negative effects of residual stress, both residual stress already present prior to machining and residual stress generated by machining itself were investigated using tungsten and cemented tungsten carbide as micro-rod workpiece materials. To determine the effects of material micro-structure, the influence of tungsten carbide grain size on the limits of minimum machinable diameter of cemented tungsten carbide rods was investigated. Comparing the limits between poly-crystal tungsten and mono-crystal tungsten, it was found that micro-machining characteristics were affected significantly by the anisotropy of the mono-crystal tungsten.