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1.
Large-Scale Metrology - An Update   总被引:5,自引:0,他引:5  
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.  相似文献   

2.
采用等离子喷涂技术在医用纯钛基体表面构建出微纳米多级结构钽涂层。利用SEM、EDS和XRD分析微纳米多结构钽涂层的形貌、化学组成和物相组成,并根据ASTM C633-79评价涂层与基底的结合强度;采用牛血清蛋白(BSA)对比研究了钛基钽涂层与医用纯钛对照样表面的蛋白吸附行为。结果表明,在喷涂距离为110 mm、喷涂功率为30 k W时制备的钛基钽涂层具有典型微纳米多级结构特征,且与基体结合强度好、Ta相对含量高;蛋白吸附实验表明钛基钽涂层表面蛋白吸附量均高于医用纯钛对照样,具有良好的蛋白吸附能力。  相似文献   

3.
Probing Systems in Dimensional Metrology   总被引:6,自引:0,他引:6  
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.  相似文献   

4.
5.
Micro and Nano Machining by Electro-Physical and Chemical Processes   总被引:8,自引:0,他引:8  
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.  相似文献   

6.
Optical Methods for Dimensional Metrology in Production Engineering   总被引:3,自引:0,他引:3  
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.  相似文献   

7.
Metrology of freeform shaped parts   总被引:2,自引:0,他引:2  
E. Savio  R. Schmitt 《CIRP Annals》2007,56(2):810-835
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.  相似文献   

8.
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.  相似文献   

9.
熔模铸件的尺寸稳定性和精度   总被引:4,自引:0,他引:4  
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。  相似文献   

10.
金涛 《机床与液压》2018,46(4):134-138
全面介绍了颗粒度计量的专业内涵,概括了颗粒度计量的基本特点,分析了它在专业属性、技术特性方面技术特征,描述了颗粒度计量所具有的管理特性,深入剖析了颗粒度计量所具有的不同功能特性,体现了其基础关键作用。在不同角度对颗粒度计量主要特征进行系统分析的基础上,界定了颗粒度计量所涵盖的专业范围,进一步阐明了颗粒度计量在国民经济建设和国防军工建设中发挥的重要作用,有助于全面、正确地认识颗粒度计量特性、作用及贡献。  相似文献   

11.
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.  相似文献   

12.
提出基于体外超声波供能的体内微致动器和微电源设计方案。微致动器、微电源内有超声波吸收液体,将体外发射到体内的超声波吸收转换为热能。热能传递给热膨胀液体,液体热胀冷缩,获得机械伸缩动作。升温后的超声波吸收液体和人体温度差,可以通过热电元件,转换为电能。  相似文献   

13.
胡飞  顾大强  陈柏 《机床与液压》2006,(12):9-11,17
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。  相似文献   

14.
Hydrophobic Cu surfaces with tunable regular microstructure and random nanostructures were fabricated by nanosecond pulsed laser texturing and chemical etching. The regular micro-scale roughness can be tuned from 5 μm to 30 μm Rz by nanosecond laser texturing while the ligament width and spacing of the random nano porosity about 10-50 nm can be realized by selective chemical etching. Wettability tests demonstrate that the Cu surface with this micro/nanostructural hierarchy, analogous to that of lotus leaves found in nature, is superhydrophobic with a water contact angle around 153°. The random nanostructure by selective etching plays an important role for hydrophobicity in addition to the regular microstructure by nanosecond laser texturing.  相似文献   

15.
对我国三种典型的熔模铸造厂的产品尺寸进行了测量统计,对照现行的铸件尺寸公差国际标准ISO8062-84和国家标准GB6414-86,表明A、B两类工厂生产的铸件尺寸公差达到了GB6416-86之CT5 ̄CT7级,而C类为CT8级。  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
纳米防腐耐磨涂料的制备及其性能研究   总被引:1,自引:0,他引:1  
制备了一种纳米防腐耐磨涂料,为了考察纳米材料在防腐耐磨涂料中的作用机制,对其进行性能检测和各种技术表征,研究结果表明:纳米SiO2由于呈三维网络结构和高的表面活性,大大增强了涂层的致密化和结合力;微量的SiC纳米粒子能有效提高环氧树脂的耐磨性.纳米SiC粒子和基体环氧树脂之间建立了较强的相互作用(包括化学键合与物理作用),材料界面强度得以提高,从而大大提高了涂层的耐磨防腐性能.  相似文献   

19.
Multisensor data fusion in dimensional metrology   总被引:2,自引:0,他引:2  
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.  相似文献   

20.
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.  相似文献   

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