水浸超声波探伤在黄金掺铱制品中的应用

采用水浸超声波探伤的方法对黄金掺铱制品进行快速检测,当扫查灵敏度增加到89d B时,可以观察到缺陷存在。用金相显微镜观察到样品中的铱,能谱扫描证实了铱的存在,为超声波探伤检测结果提供了佐证。     

利用大单晶生产铱制品

铂族难熔金属─铱是唯一一种能够在２０００℃温度的侵蚀性介质中使用的结构材料。生产铱制品时必须解决的一个主要问题是如何排除其晶界脆性。研究表明,利用直径５０ｍｍ～６０ｍｍ的大单晶作坯料,是解决铱晶界脆性最有效的方法。 叶卡捷琳堡有色金属加工厂开发了利用原生铱和不同等级合铱废料制取高纯铱的火法冶金工艺。铱深度提纯的最终阶段要采用电子束区域熔炼法培育大单晶。利用优质大单晶详细研究了铱和钉的物理机械性能,查明了这两种金属产生脆性的原因。 制定了设备的最佳工作规范,培育了规定完善程度的单晶。讨论了工业生产铱…     

黄金制品表层颜色变化的原因分析及处理方法

分析了黄金制品表面红斑与白斑的形成原因,在模拟条件下进行验证,并进行了消除红斑、白斑试验。结果表明,黄金制品表面的红斑可能为杂质氧化形成,可用热稀盐酸清洗去除;黄金制品表面的白斑可能为金汞齐,经450℃/30 min+910℃/10 min热处理可消除。2种处理方法对黄金制品原有表面光泽影响都很小,且都不影响原有成色以及质量。     

央行：个人携带200克以上黄金进出境须缴税

为了规范和促进黄金及黄金制品进出口业务发展，保护当事人的合法权益，央行按照相关法规起草发布了《黄金及黄金制品进出口管理办法（征求意见稿）》，向社会公开征求意见，截止日期为10月29日。征求意见稿规定，个人携带自用黄金及黄金制品进出境，重量超过200克的，应当主动向海关申报并凭中国人民银行及其分支机构出具的《中国人民银行个人携带黄金及黄金制品进出口准许证》办理交税、通关手续。     

我国黄金制品进出口管理范围扩大

为加强黄金及其制品的管理，近日中国人民银行联合海关总署发出公告，将黄金表壳、黄金表带纳入黄金及其制品进出口管理范围。根据公告，自2008年8月1日起，将黄金表壳（按重量计含金量在80％及以上）、黄金表带（按重量计含金量在80％及以上）纳入《黄金及其制品进出口管理商品目录》。     

黄金制品进出口管理办法（征求意见稿）

为进一步做好黄金制品进出口管理工作，规范黄金制品进出口行为，根据《中华人民共和国金银管理条例》，中国人民银行制定了《黄金制品进出口管理办法（征求意见稿）》，现向社会公开征求意见。     

黄金表壳、黄金表带纳入黄金及其制品进出口管理范围

为加强黄金及其制品的管理，根据《中华人民共和国金银管理条例》（国发[1983]95号文印发）有关规定，中国人民银行、海关总署日前发布公告，将黄金表壳、黄金表带纳入黄金及其制品进出口管理范围。     

铱片的显微组织与室温拉伸断裂机制研究

采用辉光放电质谱法(GDMS)、光学显微镜(OM)、扫描电镜(SEM)和力学试验机等测试手段,对不同加工状态的铱片杂质元素含量、金相组织、断口形貌和室温力学性能进行了研究。结果表明:加工状态对铱片的力学性能有重要影响,1 mm厚的热轧态铱片平均抗拉强度为213.6 MPa,延伸率为2.52%,主要为脆性沿晶断裂,部分为脆性穿晶解理断裂;而0.1 mm厚的冷加工态铱片平均抗拉强度为954.1 MPa,延伸率为0.55%,断裂模式主要为脆性穿晶断裂;两者在断裂之前均未发生明显的塑性变形,表现为脆性断裂模式。     

饰金新族——钛金

<正> 黄金或镀金制品,人见人爱。但黄金稀贵,价格很高,人们为了节约金子,又想得到制品表面具有金子那样黄灿灿的色泽,于是仿金镀层、仿金涂料和金属镀层相结合等技术应运而生,并且获得蓬勃的发展,为寻找黄金代用品开创了新路。 钛金是饰材的新族。钛金学名叫氮化钛,它是钛金属和氮气的化合物,为一种金黄色的粉末。氮化钛溅射镀可以得到金子一样色泽的仿金制品,镀层不是黄金,却胜似黄     

放射性同位素电池用铱合金包壳材料的研究进展

放射性同位素电池(RTG)对包壳材料的高温抗氧化性能有特别的要求,百瓦级以下的包壳材料可以使用Pt-30Rh合金,百瓦级以上的包壳材料需使用工作温度更高的铱合金。本文对铱合金包壳材料中掺杂钨、钍和铝等元素对金相组织结构、高温耐腐蚀性能和加工性能的影响,概述了高频感应熔炼、电子束熔炼和真空电弧熔炼等加工工艺的发展。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.