Optimization of Set-up Conditions for Stability of The Centerless Grinding Process

The stability of the centerless grinding process is very sensitive to the set-up conditions due to the uniqueness of the work-holding system. Centerless grinding produces precision components with high productivity only when the set-up condition is optimally chosen. This paper describes the effect of set-up conditions on three stability criteria of the centerless grinding system. It also presents guidelines for determining proper set-up conditions to avoid spinners, chatter vibration and roundness problems. Finally, an algorithm for providing the optimum set-up condition based on process aims is proposed and the simulation results are discussed.     

ISO和ASTM标准中无缝钢管探伤方法对比分析

介绍了ISO 10893标准2011版和ASTM系列探伤方法标准,并与旧标准进行对比;分析了两个系列标准在检测管径范围、对比样管选材、人工缺陷形状及尺寸、验收等级、探伤报告要求、检测方法局限性等方面的异同。分析认为：两个系列标准在探伤技术方法方面没有实质性的区别,但在对比样管选材、人工缺陷形状及尺寸、验收等级等方面的要求不同,应视采用探伤方法标准分别对待。     

New method for determination of the pose of the grinding wheel for thinning drill points

Traditionally, twist drills are reconditioned by thinning the web so the correct chisel edge length is restored. Recently, thinning has been included in the original design of drills so as to reduce torque and tool force. Because the International Standards Organization (ISO) has a system which can comprehensively model conventional twist drills but cannot model thinning specifications, this paper presents a system for precise mathematical modeling and CNC control of a 6-axis grinding workstation for drill thinning. The presented method determines the position and orientation of the grinding wheel based on the evaluated rake and clearance angles of ISO standards for 2-flute twist drills. The mathematical model and background are discussed. For verification and demonstration, two experimental drills are produced to the identical ISO standard except that one is thinned. The modeling herein is of value to industry and research if incorporated into computer software for drill design and manufacture. It is suitable for linear notch-type cutting with controlled variable rake angle along the secondary cutting edge for purposes of thinning, notching, dubbing and advanced drill research.     

Quality Considerations for the Evaluation of Thermal Spray Coatings

Revealing the true structural and mechanical properties is of utmost importance for the optimized use of thermal sprayed coatings. Only the true properties can be expected to correlate to the spray parameters. During the recent decade, the gas turbine industry has experienced a focus on the laboratory procedures being the weakest link in a frozen and robust process. This article will show several results indicating that the laboratory procedures are more essential to the evaluation results than the spray parameters themselves. With new and robust laboratory techniques, the true properties of thermal spray coatings are revealed, causing a major problem with respect to the quality standards developed 30-40 years ago. In many cases, these old specifications need updates, which is a difficult task from a cost, time, and quality perspective for OEM’s. Coatings that have been successfully used for almost half a century no longer conform to the specification they were optimized to, because of these new appropriate laboratory techniques and procedures. What is actually meant when stating the following? (1) The coating has 5% porosity; (2) No cracks are allowed; (3) Tensile bond is 50 Mpa; (4) Hardness is 1000 HV; and (5) Coating thickness is 100 μm. This article also initiates a discussion on the measurement inaccuracies, for testing of thermally sprayed coatings, with respect to the commonly used general international standards (such as QS9000, ISO17025, AS9003, and ISO10012), as well as with respect to recommendations from the Six Sigma methodology.     

基于Ontology的装配公差规范的自动生成

针对几何产品公差规范设计中存在的不确定性问题,文章将本体理论引入到装配公差规范的设计中,为装配公差规范的自动化、智能化设计提供一种可行的方法。首先构建装配公差规范层次化表示模型,并采用OWL DL断言表示模型层次间的约束关系;其次,根据装配公差规范中的概念和关系,构建装配公差规范的本体模型;再次,根据装配公差规范设计领域的专家知识,使用语义网规则语言(SWRL)构建装配公差规范设计的推理规则;然后,根据构建的本体表示模型及定义的推理规则,构建装配公差规范设计知识库,在此基础上编写装配公差规范智能化设计算法;最后,以齿轮减速器为实例说明了装配公差规范自动生成的过程,并分析验证了该方法的有效性。     

基于Pro/TOOLKIT的综合信息模型的加工工艺决策研究

根据单特征加工信息不能反映零件全部工艺决策信息的情况,引入相关特征约束对工艺决策中的特征间约束进行描述,提出零件的综合信息模型概念;把零件加工工艺信息和特征间相关约束信息引入零件工艺决策,提出一种基于综合信息模型的工艺路线决策算法,并在Pro/TOOLKIT环境下使用MS VC 6.0编程开发出了MOLDAPPS原型系统并予以实现。     

关于GB/T 24000-ISO 14000系列标准

阐述了ISO14000系列标准产生的背景、已发布的5个标准简况、ISO／TC207正在起草的国际标准及其发展趋势；介绍了实施ISO14000系列标准的作用和意义以及我国推行ISO14000系列标准的原则和计划；指出了ISO14000系列标准与ISO9000族标准的关系。     

Interactive surface modelling, an implementation of an expert system for specification of surface roughness and topography

Making roughness a useful tool for obtaining optimally functional surfaces demands a high quality foundation for surface specifications. Erroneous specifications in many cases lead to costly production and perhaps nonfunctional surfaces. The Interactive Surface Modelling system, ISM, presented in this paper, addresses those problems with an approach where functional demands control the route from specification of parameters through manufacturing preparation to measurement of the machined surface. Here, the operator, be it the designer, the production engineer, or the quality control engineer, can interactively reason with the system to reach a suitable specification with the aid of integrated software in a PC-Windows environment controlled by an expert system software. The representation of the surface's 3D geometry then is a natural component. The access to depiction and literature references and standards is implemented together with the ability to serve the user with graphic feedback by generating synthetic surfaces from the specification made. The described features have been implemented in a prototype developed in cooperation between Volvo and Chalmers on two functional surfaces: cylinder liners and synthetic leather for the automotive industry. Problems with specifying correct roughness and topography actually have emerged when changes have been made of material or manufacturing process for an old and proven product. This has shown that knowledge is missing or incomplete about proper intervals for roughness parameter values for definition of the relationship between a surface's function and its parameters . The result is misunderstandings and errors. By letting ISM be a base for continuous updating and modification of knowledge, opportunities will be created for increased quality of surface roughness specifications through this systematic approach to the complex, expanding field of Surface Roughness and Surface Topography.     

Activity and standards of ISO and IEC in the field of corrosion and corrosion protection

Some papers devoted to the ISO standards in the sphere of corrosion and corrosion protection of metals and alloys, as well as those dealing with the work of the ISO technical committee TC 156 Corrosion of metals and alloys were already published in this [2, 3] and other [4, 5] Journals. For the past period, the role of ISO standards in the practice of engineering and research investigation became more substantial. A new version of ISO 9000, the most popular among the ISO standards, was published. Certifying according to the requirements of ISO 9000 and 14000 standards series became an important criterion of the competitive capacity of an experimental laboratory or company specializing in the sphere of scientific-technical engineering and designing. Despite the status of the free-will application of standards, the conformity to the requirements of ISO standards in the sphere of quality systems and ecological management became a serious factor determining the competitive capacity of any product, including scientific-technical design. Conformity of the production to the standards of 9000 and 14000 series becomes an obligatory requirement for the providers.Translated from Zashchita Metallov, Vol. 41, No. 2, 2005, pp. 192–203.Original Russian Text Copyright © 2005 by Samoilova, Zamyatina.ISO is the International Organization for Standardization [1] that develops international standards for almost all the branches of science and technology, except for electrical and electronic engineering, which fall in the sphere of competence of the International Electrotechnical Commission (IEC).     

Development and Application of a Wheel Based Process Monitoring System in Grinding

As an advantage to conventional monitoring systems sensor equipped grinding wheels offer the possibility to gain information on the process status from direct measurements of physical quantities in the contact zone. This can be realized by the integration of small temperature and force sensors into segmented grinding wheels. A new thermocouple sensor concept was developed whose novelty is the continuous contacting of the thermocouple by the grinding wheel wear. Further tests where conducted using a piezoelectric sensor integrated into the grinding wheel. By this set-up, forces in grinding as well as in dressing processes were obtained. After assessing the system's capability for monitoring grinding and dressing processes tests in an industrial environment showed the reliability of the monitoring system which therefore may become the basis for a novel kind of process control in the future.     

健全质量体系生产优质铸件

依据 Ｉ Ｓ Ｏ９００ １ 标准中的２０ 项要素，简要介绍了在铸造过程中的质量管理和质量保证体系。重点阐述铸件设计（ 工艺） 控制、工序控制、不合格品控制，纠正和预防措施。     

25MN异型材钢挤压机组设计与开发

介绍了新研发25MN异型材钢挤压机组生产能力、工艺布置及生产装备,具体阐述了机组的工艺参数选择、工艺难题及25MN异型材钢挤压机的结构特点和主要参数,为异型材钢挤压生产提供应用参考。     

Thermal Spray Coatings on Orthopedic Devices: When and How the FDA Reviews Your Coatings

Thermal spray coatings have been commonly applied on medical devices for various reasons, e.g., surface roughening, biological fixation, and similarity of chemical composition to bone minerals. Generally, to introduce a thermal spray-coated device to the US market, a premarket review of the coated device is necessary by the US Food and Drug Administration (FDA). This article aims to improve understanding regarding FDA review of thermal spray coatings in orthopedic medical device marketing applications and expectations for information to be submitted as part of this process. While different thermal spray technologies and materials have been used for coatings on medical devices, thermal spray coatings often seen by the FDA on orthopedic devices include plasma-sprayed titanium (Ti) coatings and hydroxyapatite (HA) coatings as well as Ti/HA dual coatings. The coated devices are mostly metals (e.g., Ti alloy, cobalt-chromium alloy, stainless steel alloys) and some polymers (e.g., polyetheretherketone). The FDA does not clear or approve individual coatings or materials; rather, coatings and materials are evaluated as part of the final, finished medical device in the context of the specific device technological characteristics and intended use. The FDA has two current guidance documents for orthopedic implants with modified metallic surfaces and hydroxyapatite coatings, which outline the FDA’s recommendations for full characterization and testing of these two types of coatings, respectively. Additionally, the standards organizations (e.g., ISO and ASTM) have developed many materials and testing standards for these coatings, some of which are recognized by the FDA. It is helpful that the coating companies reference these standards for appropriate material/coating specifications, testing methods, and acceptance criteria. Depending on the intended use of the coated device, it is important that coating properties also address some items specific to that device type. Additionally, the impact of cleaning, sterilization, and packaging/shelf-life processes on the coating properties is also considered to ensure that the coated device is safe for its intended use.     

如何贯彻实施2000版ISO9000族标准

通过GB／T 19000 2000族标准培训班的学习，基本了解和掌握了2000版ISO9000族标准修订的背景，修改过程，8项质量管理原则，标准的过渡模式和认证组织转换后的审查要点，重点要求及其程序等，并有一些想法和建议。这些内容对即将认证或已认证的企业进行此项标准转换的理解很有帮助。     

ISO 4406新旧标准简介及修订原因说明

介绍了评定液压和润滑系统油液污染度等级的新旧两种国际标准ISO4406：1999和ISO4406：1987，其中ISO4406：1999污染度等级标准是对ISO4406：1987污染度等级标准的修订。新标准将等级代码增加到了30个，并且对报告形式和报告采用的污染颗粒尺寸都进行了修订。标准修订的根本原因是由于试验粉尘的改变（由ISOMTD粉末取代了ACFTD）以及相应的颗粒计数器校准方法的改变。     

Φ100mmAssel轧管机组的设备与工艺特点

介绍了从西班牙Tubacex钢厂引进的二手Φ100mmAssel轧管机组的设备与工艺特点，以及目前所取得的生产实绩。实践表明，该套设备所轧钢管外表面光滑，内表面仅有Assel轧管机轧制的螺旋道痕迹，全部产品的机械性能均达到标准要求，典型产品的成材率都在82％以上。     

高碳铬轴承钢现行标准的梳理及对GCr15的标准比较

梳理了高碳铬轴承钢现行的标准，列出了这些标准的标准号、名称、标准类别、标准适用范围及标准体系类别；同时以某钢铁企业为例，选用牌号成分接近的GCr15、GCr15PGI的高碳铬轴承钢的内控标准与GB/T 18254-2016及ISO 683-17进行比较，说明了不同标准对于GCr15牌号成分及相近成分轴承钢在碳化物、夹杂物及化学成分上的要求，发现我国GB/T 18254-2016较ISO 683 17更为严格，而企业内控标准则在GB/T 18254-2016的基础上做了更深入的要求。     

高碳铬轴承钢现行标准的梳理及对GCr15的标准比较

梳理了高碳铬轴承钢现行的标准,列出了这些标准的标准号、名称、标准类别、标准适用范围及标准体系类别;同时以某钢铁企业为例,选用牌号成分接近的GCr15、GCr15PGI的高碳铬轴承钢的内控标准与GB/T 18254—2016及ISO 683-17进行比较,说明了不同标准对于GCr15牌号成分及相近成分轴承钢在碳化物、夹杂物及化学成分上的要求,发现我国GB/T 18254—2016较ISO 683 17更为严格,而企业内控标准则在GB/T 18254—2016的基础上做了更深入的要求。     

Progress Towards Metal Additive Manufacturing Standardization to Support Qualification and Certification

As the metal additive manufacturing (AM) industry moves towards industrial production, the need for qualification standards covering all aspects of the technology becomes ever more prevalent. While some standards and specifications for documenting the various aspects of AM processes and materials exist and continue to evolve, many such standards still need to be matured or are under consideration/development within standards development organizations. An important subset of this evolving the standardization domain has to do with critical property measurements for AM materials. While such measurement procedures are well documented, with various legacy standards for conventional metallic material forms such as cast or wrought structural alloys, many fewer standards are currently available to enable systematic evaluation of those properties in AM-processed metallic materials. This is due in part to the current lack of AM-specific standards and specifications for AM materials and processes, which are a logical precursor to the material characterization standards for any material system. This paper summarizes some of the important standardization activities, as well as limitations associated with using currently available standards for metal AM with a focus on measuring mission-critical properties. Technical considerations in support of future standards development, as well as a pathway for qualification/certification of AM parts enabled by the appropriate standardization landscape, are discussed.