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1.
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   

2.
《CIRP Annals》2019,68(2):677-700
The needs, requirements, and on-going and future research issues in geometrical metrology for metal additive manufacturing are addressed. The infrastructure under development for specification standards in AM is presented, and the research on geometrical dimensioning and tolerancing for AM is reviewed. Post-process metrology is covered, including the measurement of surface form, texture and internal features. In-process requirements and developments in AM are discussed along with the materials metrology that is pertinent to geometrical measurement. Issues of traceability, including benchmarking artefacts, are presented. The information in the review sections is summarized in a synthesis of current requirements and future research topics.  相似文献   

3.
1 INTRODUCTIONRecently ,one dimensional (1D )nanostrcturematerialsarethefocusofconsiderableinterest ,sincethesematerialsshowdifferentphysicalandchemicalpropertiestotheirbulkcounterparts[1] .Butwell definedstructuresofthisscalearedifficulttoobtainbecauseneith…  相似文献   

4.
In this study, long term corrosion mechanisms are approached through the characterisation of corrosion products formed on ancient artefacts over 500 years. Thirty-one artefacts were sampled in the Amiens cathedral. The thick corrosion product layers have been characterised at a microscopic scale by coupling complementary microbeam analytical techniques (SEM-EDS, Raman microspectroscopy, X-ray microdiffraction and microfluorescence, X-ray absorption microspectroscopy under synchrotron radiation). The main phase of the corrosion layer is goethite but lepidocrocite and akaganeite are also present locally in the corrosion layer. In addition, the presence of low crystallinity phases (feroxyhyte and/or ferrihydrite) is showed. These phases are electrochemically reactive, thus they could play a key role in the corrosion mechanisms.  相似文献   

5.
介绍了一种自主开发设计的轧机生产过程数据记录方法和分析应用软件;该软件以TCP为采集途径并采用基于Microsoft.net平台的高级语言进行编程实现。该软件为轧机生产过程提供了实时数据采集、记录、数据统计分析和报表打印等功能,保证了产品的可追溯性,为生产操作提供量化指标,优化过程工艺,提高产品质量和生产效率;同时也为设备设计者优化设备配置提供数据支持。  相似文献   

6.
《CIRP Annals》2020,69(1):365-368
In-line product inspection and identification are emerging technologies supporting the observability and traceability of the product state evolution in multi-stage manufacturing systems. These technologies enable the dynamic implementation of defect management actions, such as product rework. However, their impact on the system quality and production logistics performance needs to be assessed in order to justify the related investments. This paper presents a theory and a methodology to predict the effective throughput of manufacturing systems with product traceability and rework, jointly considering the product and system state dynamics. The industrial benefits are validated in a real system in the semiconductor industry.  相似文献   

7.
Abstract

The 2014 Eurocorr meeting was held at the Palazzo dei Congressi in Pisa, Italy from 8 ??12th September 2014. The focus of the meeting was improving materials durability – from cultural heritage to industrial application. The meeting attracted over 948 delegates from 58 countries with Italy, France and Germany and the UK providing around half the delegates between them. Over 440 papers and 20 posters were presented during the 18 sessions and 5 workshops. Parts 1 – 4 of this report will review the technical sessions over four issues with marine corrosion, corrosion in oil and gas production, corrosion in the refinery industry, cathodic protection, corrosion in drinking water and drinking water systems, and corrosion of archaeological and heritage artefacts covered in this report.  相似文献   

8.
A micromechanical characterization had been performed on ancient artefacts corrosion products. The proposed experimental approach allies scanning electron microscopy observations, micro-indentation tests which allow the characterization of the local stiffness of elementary constituents, and finally Raman micro-spectroscopy tests which give access to the local crystallised phases of the samples. The experimental campaign contains a large series of tests, which give us the opportunity to interpret the dispersion of local stiffness measurements.  相似文献   

9.
Pitting corrosion of stainless steels Stainless steels can get pitting corrosion in halide containing solution, which make them a big risk in industrial production. Many investigations were made in the past in order to understand processes involved in pitting corrosion, pit initiation and pit growth. Results about the influence of alloying elements, their contents, the state of the structure, the condition of the surface, the content of chloride, the temperatures, the pH-value, the velocity of flow and of the oxidizer on the chloride induced pitting corrosion of passive stainless steels are presented. Electrochemical measurements and the application of surface analytical methods (SEM, SAM, XPS) with high lateral resolution are carried out. A part of the samples received a diffusion annealing in order to obtain reproducible results. Pitting Resistance Equivalents (PRE) – Pitting Index – with different multipliers are given and discussed critical. An electrochemical method for selecting materials without susceptibility to pitting corrosion are also presented.  相似文献   

10.
М.  ЮВ 曾宜安 《钢管》1992,(1):55-58
介绍了镍钼合金粉末无缝管热挤压、冷轧生产工艺,研究了工艺参数和影响产品尺寸精度、机械性能的因素等。  相似文献   

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