Alternatives to thorium additions to tungsten-based materials

Thorium and thoria additions are used in tungsten-based materials for a variety of performance-enhancing reasons, including better electron emissivity of electrodes (resulting in improved arcing behavior), higher strength and hardness,finer grain size, and better machinability. The resulting material’s radioactive potential, however, makes it subject to stringent legislation, which makes handling, use, recycling, and disposal more difficult. Therefore, research is being done on alternative additives that exhibit the same advantages as thoriated tungsten but without the drawbacks. In this respect, lanthanum and cerium-oxide doping represent competitive alternatives.     

Joining silicon nitride to itself and to metals

This article reviews the progress that has been made in developing and applying joining techniques for Si₃N₄ and discusses our understanding of the influence of process selection on the materials science of the formation and properties of joints. High-performance Si₃N₄ joints can be produced, but it is clear that much work remains to be done before the use of such joints in hot-stressed applications can be disregarded as a problem.     

传统产业获得竞争优势需注重"三个升级"

企业为了获得竞争优势,特别是传统产业改造,应该注重技术升级、员工素质升级和机制创新升级,以促进产业新兴.     

择优扶强政策与制造业“强不强”问题

自新中国成立以来,我国机械制造业一直在解决"有没有"的情况下,做着"强不强"的工作。特别是经过改革开放后的发展,机械制造业进入了"体系完整时代",经常被描述为"大而不强"。因此从20世纪末到现在,我们一直在想或试图做"强不强"的事儿,特别是最近这些年,国家一直下大力气推动解决"强不强"的问题,此中产生了一个新词汇"高质量地向高端制造业发展"。     

选择塑料模具钢的问题探讨

塑料模具钢在我国生产中应用广泛，但不成系列，本文就生产中塑料模具钢的选择问题作了探讨。     

Using fuzzy sets to assign metallurgical grades to steel

To optimize the productivity and yield of a modern high-speed continuous casting operation, it is desirable to minimize the number of metallurgical grades that have to be melted to satisfy a collection of customer orders. This problem has been addressed through the development of an expert system for selecting the set of all potential grades for each order and an optimal selection algorithm for determining the actual grades that would be required to produce all orders. As a further refinement, a fuzzy formulation with a membership function based on the likelihood of a grade meeting the customer’s specifications without difficulty has been added. This enables the plate mill to trade off minimizing the number of grades used against maximizing the likelihood that the customer specifications will be met without difficulty.     

冲天炉熔炼几个有关问题的处理

介绍与冲天炉熔炼有关的几个问题的处理方法，包括：（1）如何防止熔化带以上耐火砖容易掉落；（2）如何防止过桥、出铁口易被侵蚀；（3）固定式前炉容量大小的选择；（4）如何保持浇包尺寸；（5）加料口材料选择：（6）要否使用热风炉胆；（7）孕育处理方法与孕育量；（8）灰铸铁的含硫量；（9）风口比。     

Embedding simple machines to add novel dynamic functions to composites

One unique property of a machine-augmented composite (MAC) is its ability to convert a compressive force into a shear force, and vice versa, simply by the geometry of its angled sidewalls. The authors have discovered that a non-spinning ball dropped at a normal angle onto the MAC’s surface rebounds from that surface at an oblique angle and develops a significant rotational velocity. Through finite-element analyses, analytical study, and experiments, the magnitude and direction of the spin can be precisely controlled by tailoring the stiffness of the MAC through the properties and dimensions of its constituent materials. For more information, contact Gary F. Hawkins, The Aerospace Corporation, P.O. Box 92957 — M2/242, Los Angeles, CA 90009-2957; (310) 336-7379; fax (310) 336-5846; e-mail gary.f.hawkins@aero.org.     

郭征:创新发展 勇于超越

郭征教授是空军军医大学（原第四军医大学）唐都骨科医院院长、骨科主任、全军骨肿瘤研究所所长,已累计发表论文210篇（其中SCI论文72篇）,发明专利授权12项。担任中华医学会医学工程学分会数字骨科学组组长、中国医师协会骨科医师分会3D打印专业委员会副主任委员、中国抗癌协会骨肿瘤与骨转移瘤专业委员会副主任委员、中国抗癌协会肉瘤专业委员会骨盆学组组长、全军骨科学会骨肿瘤专业委员会副主任委员。他还是国家重点研发计划项目首席科学家,哈佛大学麻省总医院骨肿瘤研究中心讲座教授。他倡导数字技术（导航、3D打印、机器人）辅助骨肿瘤精准外科治疗理念与植入器械相结合,并于2014年领衔完成世界首例3D打印钛合金个性化锁骨和肩胛骨假体植入手术,开创了3D打印个性化假体临床应用的先河,荣立个人二等功1次、个人三等功4次,获国家科技进步一等奖、军队医疗成果一等奖和陕西省科学技术一等奖各1项,陕西省卫计委授予“三秦最美医生”称号,军队优秀专业技术人才。     

提高炼焦煤密度试验研究

用日本栗田工业株式会社提供的密度提高剂及其实验设备,对焦化厂的炼焦配煤进行了密度提高试验,试验证明添加密度提高剂后,配合煤的密度提高了4.23%～4.61%,小焦炉试验焦炭质量变化不明显。     

中国工程机械行业如何应对金融危机

在全球金融危机影响下，中国工程机械行业面临出口下滑的困境。文章分析了我国工程机械行业面临的挑战和机遇。提出加大技术引进、促进产业升级、构筑国际营销网络和推进海外并购等方法应对金融危机。     

祝贺康沫狂教授80寿辰暨执教54周年

21世纪的晨钟 ,迎来了康沫狂教授执教 5 4周年和他 80寿诞的喜庆日子 ,西北工业大学、全国热处理学会、《金属热处理学报》编辑部以及他的同事们、学生们向他表示热烈的祝贺 !康沫狂教授是我国著名金属材料科学家和教育家。 1 92 0年 1月 2 9日生于河南新野县 ,1 945年毕业于西北工学院。先后在成都空军机械学校、重庆中央工业专科学校、西北工学院、西北工业大学执教 ,曾任航空工业部科学技术委员会委员、中国航空学会理事并兼任材料科学和工程专业委员会副主任、中国高等工科学校机械制造 (热加工 )类教材编审委员会委员、《金属热处理学…     

Friction welding of molybdenum to molybdenum and to other metals

This paper presents the result of investigations into the friction welding of similar-metal and dissimilar-metal (vanadium, tantalum, niobium, titanium and copper) combinations of molybdenum and molybdenum alloy (TZM). The produced joints were subjected to microscopic examination, microhardness tests and strength tests. It has been found that refractory metals can be joined by friction welding. The friction welded joints had proper microstructures with no intermetallic phases. Friction welding parameters proper for welding TZM to other metals have been determined. The parameters can be used for the direct welding of TZM to other metals and for the welding of interlayers.     

在ASME国际性规范下如何编制WPS

本文介绍了在美国机械工程师协会国际性规范下如何编制焊接工艺规程。焊接工艺规程是焊工或者焊接操作工按规范要求制造产品焊缝的指导性文件,为焊接工作提供了强有力的文件支撑,意在与国际焊接文件编制提供借鉴。     

Introduction to patents简

正2014-01.Method for producing a cast blade for a gas turbine Patent No.:US8382433Date of Patent:2013-02-26Inventors:Brian Kenneth Wardle,et al Assignee:Alstom Technology Ltd[Switzerland]The present invention describes a method for casting a blade for a gas turbine.The blade includes an elongated airfoil which extends in the blade's longitudinal direction,merges into a blade root at the lower end,has a shroud segment at the blade tip and is pervaded by a single     

Instructions to authors

Abstract

The corrosion behaviour of standard and modified 9Cr–1 Mo ferritic steel tube containing artificial defects (holes formed by spark erosion and drilling) has been investigated under realistic steam generator conditions (334°C, heat flux 860 kW m^?2) with acid sulphate-chloride fault water chemistry. Corrosion of the tube was found to be independent of steel type, the presence of heat flux, or acid sulphate-chloride water chemistry. Wide variations were seen in the rate of magnetite deposition in heat flux and non-heat flux regions of the tube. These are attributed to the presence of a thin oxide film on the outer surface of the tube which retards the escape of corrosion hydrogen and reduces the rate of magnetite deposition. Two types of corrosion were observed in defects: accelerated general corrosion to depths of 54μm– ascribed to acid sulphate attack, and intergranular attack (IGA) to depths of ～80 μm–independent of steel type or the presence of a sensitised structure. Under these test conditions, there appears to be a threshold stress of ～150 MNm^?2 above which stress assisted IGA can occur in sensitised 9Cr–1 Mo steels.