Powder metallurgy - some economic considerations

Energy Technology Data Exchange (ETDEWEB)

Kassem, M.E.

1982-01-01

As a forming process powder metallurgy offers reductions in material and energy consumption. The engineering prerequisites and economics are discussed in relation to several industrial applications including automobile parts. 14 refs.

Metallurgy and Heat Treating. Welding Module 7. Instructor's Guide.

Science.gov (United States)

Missouri Univ., Columbia. Instructional Materials Lab.

This guide is intended to assist vocational educators in teaching a three-unit module in metallurgy and heat treating. The module is part of a welding curriculum that has been designed to be totally integrated with Missouri's Vocational Instruction Management System. The basic principles of metallurgy and heat treatment and techniques for…

Progress report of the Metallurgy Division for the period 1978-1980

International Nuclear Information System (INIS)

Sharma, B.D.; Mohan, Ashok; Bose, D.K.; Rao, C.N.; Chouthai, S.S.

1980-01-01

The research and development (R and D) work of the Metallurgy Division of the Bhabha Atomic Research Centre at Bombay for the period 1978-1980 is reported in the form of individual summaries under the headings: extractive metallurgy section, physical metallurgy section, corrosion and electrometallurgy section, ceramics section. Progress of work of beryllium pilot plant project, programme for R-5 utilisation for materials irradiation research project, development of rare, reactive and refractory metals, and development of ceramics materials for MHD programme is surveyed. Lists of publications, deputations, visits, conferences, colloquia are given. A chart at the end shows the various sections of the Division and personnel in each section. (M.G.B.)

Physical metallurgy. Vol. 6. Corrosion, oxidation and physical metallurgy applications

International Nuclear Information System (INIS)

Adda, Y.; Dupuy, J.M.; Philibert, J.; Quere, Y.

1982-12-01

This document deals with the following subjects: oxidation, corrosion and surface treatments. Some physical metallurgy applications are presented: aluminium alloys, high elastic limit materials, materials for very high temperature, nuclear metallurgy problems, composite materials, magnetic materials, very high purity materials, and, superconductor materials [fr

Weldability of powder-metallurgy molybdenum with low oxygen content

International Nuclear Information System (INIS)

Hiraoka, Yutaka; Okada, Masatoshi

1987-01-01

Relationships between the formation of weld pores and the chemical compositions in powder-metallurgy molybdenum were investigated. It is suggested that almost 100% of Ca and Mg form oxides. In contrast, Fe, Ni, Cr and Al, Si only partly form oxides. A powder-metallurgy molybdenum containing less than 84 at.ppm oxygen did not show any large weld pores. The reduction of the oxygen content was achieved by purifying the molybdenum powder. (orig.) [de

Beneficiation and extraction of nonterrestrial materials, part 2

Science.gov (United States)

Agosto, William N.

A review of options for processing extraterrestrial materials was dominated by industrial materials scientist who tried to identify which processes utilizing space materials could be implemented in the near term. The most practical process seem to us to be the extraction of lunar oxygen and the extraction of metals and ceramics from the residues of the reduction process. The growth of space activity will be accompanied by increased demand for liquid oxygen for each round trip to the Moon. The oxygen and the intermediary product water will be needed for the life support at the base. The reduced metals and ceramics may be considered byproducts or may develop into primary products. Some of the same processes would be directly applicable to recovery of products from asteroids. We also discussed other processes for directly utilizing asteroid metals. Some of the topics covered include beneficiation and oxygen extraction methods, metallurgy, and extraterrestrial cement.

Current programmes of Metallurgy Division (1991)

International Nuclear Information System (INIS)

1991-01-01

Current research and development programmes of the Metallurgy Division are listed under the headings: 1)Thrust Areas, 2)High Temperature Materials Section, 3)Chemical Metallurgy Section, 4)Metallurgical Thermochemistry Section, 5)Physical Metallurgy Section, 6)Mechanical Metallurgy Section, 7)Corrosion Metallurgy Section, 8)Electrochemical Science and Technology Section, 9)Ceramics Section, and 10)Fabrication and Maintenance Group. A list of equipment in the Division and a list of sciientific personnel of the Division are also given. (M.G.B.)

Low-Cobalt Powder-Metallurgy Superalloy

Science.gov (United States)

Harf, F. H.

1986-01-01

Highly-stressed jet-engine parts made with less cobalt. Udimet 700* (or equivalent) is common nickel-based superalloy used in hot sections of jet engines for many years. This alloy, while normally used in wrought condition, also gas-atomized into prealloyed powder-metallurgy (PM) product. Product can be consolidated by hot isostatically pressing (HIPPM condition) and formed into parts such as turbine disk. Such jet-engine disks "see" both high stresses and temperatures to 1,400 degrees F (760 degrees C).

Neutron radiography in metallurgy

International Nuclear Information System (INIS)

Rant, J.; Ilic, R.

1977-01-01

The review surveys microneutronographic and neutron-induced autoradiographic techniques and their applications in metallurgy. A brief survey of applications of neutron radiography as a method of non-destructive testing to some macroscopic problems in metallurgy is included. (author)

Preliminary analysis about reducing production costs in uranium mining and metallurgy at Fuzhou uranium mine

International Nuclear Information System (INIS)

Wu Sanmao

1999-01-01

The production costs in uranium ming and metallurgy have been analyzed quantitatively term by term according to present production situation for The Uranium Mining and Metallurgy Corp, which is part of Fuzhou Uranium Mine. The principal factors influencing on the production costs and the main means reducing the production costs have been found

Metallurgy of high-silicon steel parts produced using Selective Laser Melting

International Nuclear Information System (INIS)

Garibaldi, Michele; Ashcroft, Ian; Simonelli, Marco; Hague, Richard

2016-01-01

The metallurgy of high-silicon steel (6.9%wt.Si) processed using Selective Laser Melting (SLM) is presented for the first time in this study. High-silicon steel has great potential as a soft magnetic alloy, but its employment has been limited due to its poor workability. The effect of SLM-processing on the metallurgy of the alloy is investigated in this work using microscopy, X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD). XRD analysis suggests that the SLM high-silicon steel is a single ferritic phase (solid solution), with no sign of phase ordering. This is expected to have beneficial effects on the material properties, since ordering has been shown to make silicon steels more brittle and electrically conductive. For near-fully dense samples, columnar grains with a high aspect ratio and oriented along the build direction are found. Most importantly, a <001> fibre-texture along the build direction can be changed into a cube-texture when the qualitative shape of the melt-pool is altered (from shallow to deep) by increasing the energy input of the scanning laser. This feature could potentially open the path to the manufacture of three-dimensional grain-oriented high-silicon steels for electromechanical applications.

Promoting energy conservation in China's metallurgy industry

International Nuclear Information System (INIS)

Lin, Boqiang; Du, Zhili

2017-01-01

China is undergoing rapid industrialization and urbanization, with consequent dramatic increase in energy demand. Given energy scarcity, environmental pollution, energy security and energy cost constraints, energy conservation will be the major strategy in China's transition to a low-carbon economy. Since the metallurgy industry is a main sector of energy consumption, the efficiency of energy conservation in this industry will affect the future prospects of energy savings. This paper analyzes the energy conservation potential of China's metallurgy industry. First, seemingly unrelated regression method is applied to investigate the relationship between energy relative price, R&D input, enterprise ownership structure, enterprise scale and energy intensity of the metallurgy industry. Then, based on the SUR results, we use the scenario analysis method to predict energy consumption and savings potential in the industry in different scenarios. This paper provides references for China's government and metallurgy industry in formulating relevant energy conservation policies. - Highlights: • Seemingly unrelated regression method is applied to analyze the energy intensity of metallurgy industry. • We use the scenario analysis method to predict energy consuming and energy saving of Chinese metallurgy industry. • Provide references for China's government and metallurgy industry in formulating relevant energy conservation policies.

Superconductors by powder metallurgy techniques

International Nuclear Information System (INIS)

Pickus, M.R.; Wang, J.L.F.

1976-05-01

Fabrication methods for Nb 3 Sn type compounds are described. Information is included on the Bell Telephone process, the General Electric tape process, superconductor stability, the bronze process, powder metallurgy multifilamentary tapes and wires, and current assessment of powder metallurgy superconducting wire

Metallurgi for Ingeniører

DEFF Research Database (Denmark)

Pedersen, Jan

Ny gennemarbejdet udgave af den klassiske "Metallurgi for Ingeniører", først skrevet af K. Offer Andersen i 1962......Ny gennemarbejdet udgave af den klassiske "Metallurgi for Ingeniører", først skrevet af K. Offer Andersen i 1962...

Proceedings of the International Symposium on quantitative description of metal extraction processes

International Nuclear Information System (INIS)

Themelis, N.J.

1991-01-01

This book contains the proceedings of the H.H. Kellogg International Symposium. Topics include: Extractive metallurgy; Thermochemical phenomena in metallurgy; Thermodynamic modeling of metallurgical processes; and Transport and rate phenomena in metallurgical extraction

Development and prospect of china uranium mining and metallurgy

International Nuclear Information System (INIS)

Que Weimin; Wang Haifeng; Niu Yuqing; Gu Wancheng; Zhang Feifeng

2007-01-01

The development of industry of uranium mining and metallurgy in China has been reviewed generally, emphasizing on investigation approaches and application levels of uranium mining technologies such as in-situ leaching, heap leaching, stope leaching: on the basis of analysis on status of uranium mining and metallurgy and problems existed, also considering the specific features of deposit resources, the development orientation of uranium mining and metallurgy in China is pointed out. The industry of China uranium mining and metallurgy is faced to new opportunity of development and challenge in 21st century, the only way to realize sustainable development of uranium mining and metallurgy and harmonious development between economy and environment is to develop new technology on mining, ore beneficiation and metallurgy, increase the utilization level of uranium resources, low down impact on environment caused by mining and metallurgy. (authors)

Fundamentals of powder metallurgy

International Nuclear Information System (INIS)

Khan, I.H.; Qureshi, K.A.; Minhas, J.I.

1988-01-01

This book is being presented to introduce the fundamentals of technology of powder metallurgy. An attempt has been made to present an overall view of powder metallurgy technology in the first chapter, whereas chapter 2 to 8 deal with the production of metal powders. The basic commercial methods of powder production are briefly described with illustrations. Chapter 9 to 12 describes briefly metal powder characteristics and principles of testing, mixing, blending, conditioning, compaction and sintering. (orig./A.B.)

Powder metallurgy techniques in nuclear technology

International Nuclear Information System (INIS)

Mardon, P.G.

1983-01-01

The nuclear application of conventional powder metallurgy routes is centred on the fabrication of ceramic fuels. The stringent demands in terms of product performance required by the nuclear industry militate against the use of conventional powder metallurgy to produce metallic components such as the fuel cladding. However, the techniques developed in powder metallurgy find widespread application throughout nuclear technology. Illustrations of the use of these techniques are given in the fields of absorber materials, ceramic cladding materials, oxide fuels, cermet fuels, and the disposal of highly active waste. (author)

Role of forgings in powder metallurgy industry

International Nuclear Information System (INIS)

Hayes, A.F.; DeRidder, A.J.

1975-01-01

Forging of powder metallurgy materials is discussed. Information and data are included on forging powder metallurgy W, Mo, In 100, Rene 95, Astroloy, Be, and Ti. It is noted that the combination of powder metallurgy and forging work provides the best product from standpoints of reproducibility, freedom from segregation, low scrap rate, and uniform mechanical properties. Experience is being used to develop contour forging from hot isostatic pressed billets or preforms. The quality of this product is under evaluation. Results show steady improvement and it is anticipated that continued effort will soon produce a reliable, less costly product. Forging can continue to be relied upon to correct subtle defects present in powder metallurgy material

Manufacture of good-weldable low oxygen molybdenum by powder metallurgy

International Nuclear Information System (INIS)

Hiraoka, Yutaka; Okada, Masatoshi; Akiyama, Takashi; Yamafuchi, Yasuo.

1984-01-01

In general most of commercial molybdenum is produced by the powder metallurgy method and is utilized as a superior heat-resisting material in many fields. Moreover, molybdenum is expected to be used as the first-wall components of JT-60 (JAERI Tokamak-60). However, one of major problems on molybdenum, particularly on powder metallurgy molybdenum, is that any sound welded joint is hard to be obtainable. In many cases weld pores are formed on welding and, therefore, ductility of the welded joint is severely degraded. The object of the present work is to get a sound welded joint without any weld pores by reducing impurity levels in the material. The materials were produced by modifying one or several parts in the ordinary manufacturing process of powder metallurgy molybdenum. Oxygen, nitrogen, carbon and other principal metallic impurities were chemically analysed. The above materials were then subjected to electron-beam-welding by using a melt-run technique, and the soundness of the welded joints was examined by optical microscopy. (author)

Solvent extraction: the coordination chemistry behind extractive metallurgy.

Science.gov (United States)

Wilson, A Matthew; Bailey, Phillip J; Tasker, Peter A; Turkington, Jennifer R; Grant, Richard A; Love, Jason B

2014-01-07

The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, M(n+), metalate anions, MXx(n-), or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal cations or metal salts into a water-immiscible solvent usually operate in the inner coordination sphere of the metal and provide donor atom types or dispositions which favour the formation of particularly stable neutral complexes that have high solubility in the hydrocarbons commonly used in recovery processes. In the extraction of metalates, the structures of the neutral assemblies formed in the water-immiscible phase are usually not well defined and the cationic reagents can be assumed to operate in the outer coordination spheres. The formation of secondary bonds in the outer sphere using, for example, electrostatic or H-bonding interactions are favoured by the low polarity of the water-immiscible solvents.

Metallurgy Department

DEFF Research Database (Denmark)

Risø National Laboratory, Roskilde

The activities of the Metallurgy Department at Risø during 1981 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, Fuel Elements. Furthermore, a survey is given of the department's participation in international collaboration...

Basic metallurgy for nondestructive testing

International Nuclear Information System (INIS)

Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

2008-01-01

For this chapter, reader will be served with the basic knowledge on metallurgy for nondestructive testing. One the main application of nondestructive testing is to detect discontinuity of mass defect in metal. As we already know, metal are widely used in many application such as in building as a system, component and engineering product. Steel and iron are metal that usually used in industry, especially heavy industry such as gas and petroleum industry, chemistry, electric generation, automobile, and military device. Based on this, basic knowledge on metallurgy must need by NDT practitioner. The combination between metallurgy and datas from radiography testing can make radiographer good interpretation on quality of the metal inspected and can used to make a good decision either to accept or not certain product, system or components.

Biennial activity report of metallurgy programme for 1987 and 1988

International Nuclear Information System (INIS)

Shanmugam, V.; Rao, B.P.C.; Bhanu Sankara Rao, K.; Muralidharan, P.; Bhaduri, A.K.; Kuppusami, P.; Shyamsunder, M.T.; Sampath, N.; Sreedharan, O.M.

1990-01-01

The research and development (R and D) activities in the field of metallurgy at Indira Gandhi Centre for Atomic Research, Kalpakkam during 1987-1988 are reported in the form of individual summaries arranged under headings : (1) Mechanical Metallurgy Section, (2) Physical Metallurgy Section, (3) Chemical Metallurgy Section, (4) Materials Technology Section, (5) Division for PIE and NDT Development and (6) Quality Engineering Section. A list of publications by the staff scientists working in the field of metallurgy during report period is given in one of the appendices. (author). figs., tabs

Mechanical properties of modified low cobalt powder metallurgy Udimet 700 type alloys

Science.gov (United States)

Harf, Fredric H.

1989-01-01

Eight superalloys derived from Udimet 700 were prepared by powder metallurgy, hot isostatically pressed, heat treated and their tensile and creep rupture properties determined. Several of these alloys displayed properties superior to those of Udimet 700 similarly prepared, in one case exceeding the creep rupture life tenfold. Filter clogging by extracted gamma prime, its measurement and significance are discussed in an appendix.

Powder Metallurgy Fabrication of Molybdenum Accelerator Target Disks

Energy Technology Data Exchange (ETDEWEB)

Lowden, Richard Andrew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kiggans Jr., James O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nunn, Stephen D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parten, Randy J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-07-01

Powder metallurgy approaches for the fabrication of accelerator target disks are being examined to support the development of Mo-99 production by NorthStar Medical Technologies, LLC. An advantage of powder metallurgy is that very little material is wasted and, at present, dense, quality parts are routinely produced from molybdenum powder. The proposed targets, however, are thin wafers, 29 mm in diameter with a thickness of 0.5 mm, with very stringent dimensional tolerances. Although tooling can be machined to very high tolerance levels, the operations of powder feed, pressing and sintering involve complicated mechanisms, each of which affects green density and shrinkage, and therefore the dimensions and shape of the final product. Combinations of powder morphology, lubricants and pressing technique have been explored to produce target disks with minimal variations in thickness and little or no distortion. In addition, sintering conditions that produce densities for optimum target dissolvability are being determined.

A millennium of metallurgy recorded by lake sediments from Morococha, Peruvian Andes.

Science.gov (United States)

Cooke, Colin A; Abbott, Mark B; Wolfe, Alexander P; Kittleson, John L

2007-05-15

To date, information concerning pre-Colonial metallurgy in South America has largely been limited to the archaeological record of artifacts. Here, we reconstruct a millennium of smelting activity in the Peruvian Andes using the lake-sediment stratigraphy of atmospherically derived metals (Pb, Zn, Cu, Ag, Sb, Bi, and Ti) and lead isotopic ratios (206Pb/ 207Pb) associated with smelting from the Morococha mining region in the central Peruvian Andes. The earliest evidence for metallurgy occurs ca. 1000 A.D., coinciding with the fall of the Wari Empire and decentralization of local populations. Smelting during this interval appears to have been aimed at copper and copper alloys, because of large increases in Zn and Cu relative to Pb. A subsequent switch to silver metallurgy under Inca control (ca. 1450 to conquest, 1533 A.D.) is indicated by increases in Pb, Sb, and Bi, a conclusion supported by further increases of these metals during Colonial mining, which targeted silver extraction. Rapid development of the central Andes during the 20th century raised metal burdens by an order of magnitude above previous levels. Our results represent the first evidence for pre-Colonial smelting in the central Peruvian Andes, and corroborate the sensitivity of lake sediments to pre-Colonial metallurgical activity suggested by earlier findings from Bolivia.

The utilization of mechanochemistry in the extractive metallurgy and at the nanocrystalline materials preparation

Directory of Open Access Journals (Sweden)

Boldižárová Eva

2002-03-01

Full Text Available The possibility of the application of mechanochemistry in the extractive metallurgy and the nanocrystalline materials preparation is studied. The aim of the experiments is the chloride leaching of a complex sulphidic CuPbZn concentrate (Hodruša-Hámre, the modification of properties of CaCO3 (Yauli, Peru for zinc sorption from model solutions and the mechanochemical reduction of copper sulphide by elemental iron.The chloride leaching of mechanically activated complex sulphidic CuPbZn concentrate is a selective process. While the recoveries of copper, lead and zinc are 65-85 %, the recoveries of silver and gold are less than 7 % and 2 %, respectively.The positive influence of CaCO3 mechanical activation for zinc sorption from ZnSO4 solution was observed. While only 58 % of zinc sorption was determined after 30 minutes for a non-activated sample, 98 % of zinc sorption was determined after 3 minutes sorption for the sample mechanically activated for 15 minutes.By the mechanochemical reduction of copper sulphide with iron, nanocrystalline copper and iron sulphide are formed. This reaction is an example of the new “solid state technology“, where chemical processes in the gaseous and liquid states are excluded.The results can serve as a contribution to the optimization of copper, lead and zinc extraction from complex sulphidic concentrates, the increase of non-ferrous metals sorption efficiency on mineral sorbents as well as to the nanocrystalline copper preparation.The application of mechanical activation has grown in the laboratory research. The Institute of Geotechnics of SAS has also achieved significant theoretical results in study of mechanical activation of sulphides and their reactivity in the different solid-phase reactions with the effect on industrial applications. The Institute has developed the technology of mechanochemical leaching (process MELT which was successfully tested in a pilot plant unit.

Self-Paced Tutorial Courses for Mineral Science - Metallurgy Departments. Final Progress Report (July 1975-August 1980).

Science.gov (United States)

Twidwell, L. G.

Four courses in extractive metallurgy (Pyrometallurgy, Hydrometallurgy, Electrometallurgy; and Physical Chemistry of Iron and Steel) were prepared in a modular, self-paced format. Development of the course materials included: (1) preparation of course outlines by unit coordinators and advisory committees; (2) approval of course outlines (included…

Ideate about building green mine of uranium mining and metallurgy

International Nuclear Information System (INIS)

Shi Zuyuan

2012-01-01

Analysing the current situation of uranium mining and metallurgy; Setting up goals for green uranium mining and metallurgy, its fundamental conditions, Contents and measures. Putting forward an idea to combine green uranium mining and metallurgy with the state target for green mining, and keeping its own characteristics. (author)

Milling and Drilling Evaluation of Stainless Steel Powder Metallurgy Alloys

Energy Technology Data Exchange (ETDEWEB)

Lazarus, L.J.

2001-12-10

Near-net-shape components can be made with powder metallurgy (PM) processes. Only secondary operations such as milling and drilling are required to complete these components. In the past and currently production components are made from powder metallurgy (PM) stainless steel alloys. process engineers are unfamiliar with the difference in machining properties of wrought versus PM alloys and have had to make parts to develop the machining parameters. Design engineers are not generally aware that some PM alloy variations can be furnished with machining additives that greatly increase tool life. Specimens from a MANTEC PM alloy property study were made available. This study was undertaken to determine the machining properties of a number of stainless steel wrought and PM alloys under the same conditions so that comparisons of their machining properties could be made and relative tool life determined.

Metallurgy in the Czech Republic: a spatio-temporal view

Directory of Open Access Journals (Sweden)

J. Suchacek

2017-01-01

Full Text Available The objective of this paper is to introduce the stochastic input-output model of the impact of metallurgy sector on the Czech economy. Contrary to original input-output model, which is of deterministic nature, we reckon with interval estimates of the development of metallurgy sector. They help us to surpass deterministic impediments when analyzing and forecasting the possible developmental tendencies of metallurgy sector in various economies.

Metals in Past Societies: A Global Perspective on Indigenous African Metallurgy Shadreck Chirikure

Energy Technology Data Exchange (ETDEWEB)

Devanathan, Ram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-10-01

This slim book (166 pages) shines a spotlight on pre-industrial African metallurgy, its global connections, and anthropological implications. It integrates seemingly disparate disciplines, such as history, geology, ethnography, archeology, and metallurgy, to illustrate the diversity and innovation in metallurgy across Africa and the role of metals in the rise of socio-economic inequalities and political power. The book has 7 chapters and the focus on metals as enablers of human needs and wants is evident in each chapter. The first chapter presents the context of the work and data sources. The second chapter focuses on the origin and development of mining and metallurgy in pre-industrial Africa. Chapter 3 is dedicated to the interaction of nature and culture in the process of mining. Chapter 4 deals with the transformation of the ore into metal by smelting and the sociocultural aspects of this process. Chapter 5 explores the social and cultural roles acquired by metals as a result of fabrication into objects. Chapter 6 examines the social role of metals, trade in metals, cultural contact, proto-globalization, and technology transfer. Finally, Chapter 7 draws lessons for global anthropology from the African experience. The sources of information are adequately cited and the long list of references at the end of each chapter will be a boon to researchers in this field. The author highlights the cultural aspects and social context of the adoption of metallurgy in Africa while drawing parallels between practices in pre-industrial Africa and those in other parts of the world. The book is peppered with delightful vignettes that offer insights into the process of transforming nature into culturally significant objects. For instance, African miners, like their counterparts in Nepal and Latin America, called upon deities, spirits and ancestors to mediate between nature and humans. Women had distinct roles in this process, but there were variations in these roles and in the

Nuclear energy in metallurgy

Energy Technology Data Exchange (ETDEWEB)

Jirak, Z; Malik, J; Vrba, J

1976-01-01

The present power situation and its estimated development with a view to metallurgy is presented. The possibilities of the development of Czechoslovak metallurgy are described with regard to conventional fuels and to nuclear power applications. The programme of the use of nuclear power in countries with a highly developed metallurgical industry, such as Japan, the FRG, etc., is presented and the technical pre-requisites for the use of nuclear power in metallurgy, namely the use of high temperature reactors and their incorporation in nuclear metallurgical complexes are discussed. The problems are indicated of the selection of suitable materials for high temperature reactors and the experience is described with the operation of such equipment. The results are given of the analysis of 10 variants of the model of a nuclear metallurgical complex manufacturing 1000 tons of sponge iron per day and having four main technological circuits (the helium circuit, the steam circuit, the reduction gas circuit and the cycle of metallurgical processes). An estimate is given of the capital costs of building a high temperature reactor, a power plant and a metallurgical complex with the reactor. The costs are also given of steel and power production in a nuclear metallurgical complex.

Current programmes on physical metallurgy and related areas in BARC

International Nuclear Information System (INIS)

1994-01-01

Current research and development programmes on physical metallurgy and related areas from the following Divisions of Bhabha Atomic Research Centre are included in this report : Atomic Fuels Division, High Pressure Physics Division, Metallurgy Division, Radio Metallurgy Division, Solid State Physics Division. Important publications corresponding to each activity have also been listed. (author)

Economic statistics for the mining and metallurgical industries: 1990. Statistique economique des industries extractives et metallurgiques annee 1990

Energy Technology Data Exchange (ETDEWEB)

Rzonzef, L.

1991-01-01

Provides economic statistics for the Belgian mining and metallurgical industries in 1990. The review is divided into 4 parts: the extractive industries (including an analysis of the coal market and mines, quarries and associated industries); coke and briquette making; metallurgy (i.e. blast furnaces, steel making, rolling mills and manpower and materials consumption in the steel industry); and the extraction of sand from the Belgian continental shelf. 17 tabs.

Permanent magnets and its production by powder metallurgy

Directory of Open Access Journals (Sweden)

Enrique Herraiz Lalana

2018-06-01

Full Text Available In this work, the historical relationship between permanent magnets and powder metallurgy is reviewed. Powder metallurgy is a manufacturing technique based on the compaction of powders that are sintered to create a solid product. This technique was used in the production of permanent magnets for the first time in the 18th century and, nowadays, most permanent magnetic materials are manufacturing by this mean. Magnetic properties are highly dependent on the microstructure of the final product, the magnetic alignment of domains and presence of porosity, to mention a few, and powder metallurgy enables fine control of these factors.

Powder metallurgy and fabricating processes of cermet and metmet fuel in Russia

International Nuclear Information System (INIS)

Vatulin, A.; Konovalov, I.; Savchenco, A.; Stetsky, Y.; Trifonov, Y.; Bochvar, A.A.

2000-01-01

Methods of powder metallurgy are widely used for manufacturing of various components of reactor core: beryllium reflectors, absorbers, parts of controlling and safety systems, fuel pellets for fuel elements of power reactors and etc. The new problems arising before atomic engineering associated with increasing requirements to safe operation of reactors, non-proliferation of the nuclear weapons and utilization of plutonium stockpile in the world, served as a push to development of new kinds of dispersion nuclear fuel CERMET, CERCER, METMET. The bases of fabricating processes of such compositions are the methods of powder metallurgy. In this report some results of research activities on the development of new kinds of CERMET and METMET fuel and fuel elements for different type reactors are presented. (author)

Mechanical properties of AZ31 alloy processed by a green metallurgy route

International Nuclear Information System (INIS)

D'Enrico, F.; Garces, G.; Hofer, M.; Kim, S. K.; Perez, P.; Cabeza, S.; Adeva, P.

2013-01-01

Recently it has been proved that molding of defect-free components of various commercial alloys of magnesium can be carried out successfully when small amounts of CaO are added to the melt, making unnecessary the use of SF 6 coverage. In the case of AZ alloys, this process also remarkably improves their mechanical properties not only by the greater cleaning of alloys but also by the formation of CaAl 2 phase. This work, part of the Green project Metallurgy (http://www.green-metallurgy.eu) funded by the European Union (LIFE+2009), studies the influence of different CaO additions on the microstructure and mechanical properties of AZ31 Eco-Mg alloy. The alloy was processed by a conventional route involving extrusion of as-cast rods as well as by a powder metallurgy route (PM) using chips as starting material. The objective was to analyze the viability of recycling machining chips to manufacture components for the automobile industry and transportation in general, because of its low cost and environmental impact. It has been demonstrated that alloys processed from chips exhibit the highest tensile stress values, close to 320 MPa. (Author)

A major advance in powder metallurgy

Science.gov (United States)

Williams, Brian E.; Stiglich, Jacob J., Jr.; Kaplan, Richard B.; Tuffias, Robert H.

1991-01-01

Ultramet has developed a process which promises to significantly increase the mechanical properties of powder metallurgy (PM) parts. Current PM technology uses mixed powders of various constituents prior to compaction. The homogeneity and flaw distribution in PM parts depends on the uniformity of mixing and the maintenance of uniformity during compaction. Conventional PM fabrication processes typically result in non-uniform distribution of the matrix, flaw generation due to particle-particle contact when one of the constituents is a brittle material, and grain growth caused by high temperature, long duration compaction processes. Additionally, a significant amount of matrix material is usually necessary to fill voids and create 100 percent dense parts. In Ultramet's process, each individual particle is coated with the matrix material, and compaction is performed by solid state processing. In this program, Ultramet coated 12-micron tungsten particles with approximately 5 wt percent nickel/iron. After compaction, flexure strengths were measured 50 percent higher than those achieved in conventional liquid phase sintered parts (10 wt percent Ni/Fe). Further results and other material combinations are discussed.

A Guide for Planning Facilities for Occupational Preparation Programs in Metallurgy Technology. Interim Report. Research 28.

Science.gov (United States)

German, Carl, Jr.

The major purpose of this guide is to elicit the information necessary for writing educational specifications for facilities to house technical education programs in metallurgy. It is organized in these parts: (1) Part I discusses the major purpose, underlying assumptions, recent instructional trends, and guiding principles utilized in the…

Environmental protection technologies and prospect for uranium mining and metallurgy in China

International Nuclear Information System (INIS)

Pan Yingjie

2002-01-01

Based on practices of production and environmental protection of China's uranium mining and metallurgy, control and protection of the three wastes in uranium mining and metallurgy are discussed. Prospects for environmental protection technologies of uranium mining and metallurgy is made

Advanced powder metallurgy aluminum alloys and composites

Science.gov (United States)

Lisagor, W. B.; Stein, B. A.

1982-01-01

The differences between powder and ingot metallurgy processing of aluminum alloys are outlined. The potential payoff in the use of advanced powder metallurgy (PM) aluminum alloys in future transport aircraft is indicated. The national program to bring this technology to commercial fruition and the NASA Langley Research Center role in this program are briefly outlined. Some initial results of research in 2000-series PM alloys and composites that highlight the property improvements possible are given.

Copper alloys with improved properties: standard ingot metallurgy vs. powder metallurgy

Directory of Open Access Journals (Sweden)

Milan T. Jovanović

2014-09-01

Full Text Available Three copper-based alloys: two composites reinforced with Al2O3 particles and processed through powder metallurgy (P/M route, i.e. by internal oxidation (Cu-2.5Al composite and by mechanical alloying (Cu-4.7Al2O3 and Cu-0.4Cr-0.08Zr alloy produced by ingot metallurgy (vacuum melting and casting were the object of this investigation. Light microscope and scanning electron microscope (SEM equipped with electron X-ray spectrometer (EDS were used for microstructural characterization. Microhardness and electrical conductivity were also measured. Compared to composite materials, Cu-0.4Cr-0.08Zr alloy possesses highest electrical conductivity in the range from 20 to 800 ℃, whereas the lowest conductivity shows composite Cu-2.5Al processed by internal oxidation. In spite to somewhat lower electrical conductivity (probably due to inadequate density, Cu-2.5Al composite exhibits thermal stability enabling its application at much higher temperatures than materials processed by mechanical alloying or by vacuum melting and casting.

Preparation of nitinol by non-conventional powder metallurgy techniques

Czech Academy of Sciences Publication Activity Database

Novák, P.; Moravec, H.; Salvetr, P.; Průša, F.; Drahokoupil, Jan; Kopeček, Jaromír; Karlík, M.; Kubatík, Tomáš František

2015-01-01

Roč. 31, č. 15 (2015), s. 1886-1893 ISSN 0267-0836 R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:68378271 ; RVO:61389021 Keywords : shape memory alloys * SHS process * SEM * powder metallurgy Subject RIV: JG - Metallurgy Impact factor: 1.008, year: 2015

Structure and properties of powder metallurgy constructional steel of different densities

International Nuclear Information System (INIS)

Gulyaev, A.P.; Moskvina, T.P.

1986-01-01

A specific feature of powder metallurgy steels is porosity, the degree of which depends upon the method of their production. This article establishes the influence of a small amount of porosity on the mechanical properties of powder metallurgy constructional steel. The structure of heat-treated cast and powder metallurgy steels with different porosities are shown. The results of mechanical tests of the experimental steels with different porosities are shown. With an increase in porosity the nonmetallic inclusion rating of the powder metallurgy constructional steel increases, primarily as the result of the increase in the coarse particles, which is caused by the lower degree of plastic deformation in pressing. With an increase in porosity the mechanical properties of the powder metallurgy steel become poorer: the hardness and strength properties with a porosity of more than 3-5%, the plasticity with more than 1-2%, and the toughness even with a porosity of 1%

Metallurgy Department publications 1988

International Nuclear Information System (INIS)

Schroeder Pedersen, A.; Bilde-Soerensen, J.B.

1989-08-01

A presentation (including abstracts) of scientific and technical publications and lectures by the staff of the Metallurgy Department during 1988 is given. The list comprises journal papers, conference papers, reports, lectures and poster presentations in the following catagories: Publications, Lectures and Poster Presentations. (author)

Metallurgy Department publications 1989

International Nuclear Information System (INIS)

Horsewell, A.

1990-08-01

All publiclations by the staff of the Metallurgy Department during 1989 are listed. This list is divided into three sections as follows: Publications (journal and conference papers, reports); Lectures (public lecture presentations) and Posters (poster presentations at conferences and symposia). Abstracts are included. (author)

Metallurgy and foundry practice. German-English. With 40,000 citations. Metallurgie und Giessereitechnik. Deutsch-Englisch. Mit etwa 40,000 Wortstellen

Energy Technology Data Exchange (ETDEWEB)

Stoelzel, K [ed.

1986-01-01

The dictionary represents the German-English terminology of the broad field of metallurgy (the dressing of ores and fluxes, pig iron and steel making, powder and nonferrous metallurgy, forming processes etc.) as well as of the broad field of foundry practice. Apart from the theoretical fundamental principles emphasis is on the problems of materials working and materials testing. Moreover, the dictionary considers a number of technical terms concerning the hardening, surface treatment and corrosion of materials.

Welding Metallurgy and Weldability of Stainless Steels

Science.gov (United States)

Lippold, John C.; Kotecki, Damian J.

2005-03-01

Welding Metallurgy and Weldability of Stainless Steels, the first book in over twenty years to address welding metallurgy and weldability issues associated with stainless steel, offers the most up-to-date and comprehensive treatment of these topics currently available. The authors emphasize fundamental metallurgical principles governing microstructure evolution and property development of stainless steels, including martensistic, ferric, austenitic, duplex, and precipitation hardening grades. They present a logical and well-organized look at the history, evolution, and primary uses of each stainless steel, including detailed descriptions of the associated weldability issues.

Thermogravimetric control of intermediate compounds in uranium metallurgy

International Nuclear Information System (INIS)

Gasco Sanchez, L.; Fernandez Cellini, R.

1959-01-01

The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs

Biennial activity report of Metallurgy Division for 1989 and 1990

International Nuclear Information System (INIS)

Kamachi Mudali, U.; Muraleedharan, P.; Parameswaran, P.; Swaminathan, K.; Sreedharan, O.M.

1993-01-01

This is the first divisional biennial report of the Metallurgy Division of Indira Gandhi Centre for Atomic Research, for the year 1989-1990, after formation of the Metallurgy Division in September 1988. Major areas of work in the Division relate to aqueous corrosion and localised corrosion, stress corrosion cracking and liquid metal corrosion, high temperature oxidation, thermodynamic studies, physical metallurgy studies for structure-property correlations and failure analyses. The principal materials of studies have been the austenitic stainless steels, the current materials of construction in the Fast Breeder Test Reactor and the candidate materials for the Prototype Fast Breeder Reactor

Biennial activity report of Metallurgy Programme - 1985 and 1986

International Nuclear Information System (INIS)

Mallika, C.; Sreenivasan, P.R.; Muraleedharan, P.; Shyamsunder, M.T.; Kuppuswami, P.; Sampath, N.; Bhaduri, A.K.; Sreedharan, O.M.

1988-01-01

The biennial activity report of the Metallurgy Programme of the Indira Gandhi Centre for Atomic Research covers the period of the years 1985 and 1986. Along with NDT, welding metallurgy, low cycle fatigue, creep and creep fatigue interactions, structure-property correlations, thermodynamics and corrosion metallurgy of alloy steels with respect to their compatibility with aqueous and liquid sodium environments continue to be the major thrust areas of the Programme. Some of the basic research contributions of the Programme are: the observation of uniform and homogeneous distribution of voids in cyclically deformed 304 SS, the role of grain boundaries and precipitation in dynamic strain ageing of 316 SS and the determination of the activities of component metals in 316 and 304 SS by metastable EMF method. (author)

Industrial applications and metallurgy

International Nuclear Information System (INIS)

Torres M, N.; Melendrez C, G.; Morales, F.L.

1989-01-01

From 1961 the use of nuclear energy in the industrial field in Colombia has a big advance. Today nuclear isotopes are used by private companies in this kind of application the Area of Industrial Applications and Metallurgy was the institution section that has trained and has transferred the technology needed for this purpose

Formalization of Technological Knowledge in the Field of Metallurgy using Document Classification Tools Supported with Semantic Techniques

Directory of Open Access Journals (Sweden)

Regulski K.

2017-06-01

Full Text Available The process of knowledge formalization is an essential part of decision support systems development. Creating a technological knowledge base in the field of metallurgy encountered problems in acquisition and codifying reusable computer artifacts based on text documents. The aim of the work was to adapt the algorithms for classification of documents and to develop a method of semantic integration of a created repository. Author used artificial intelligence tools: latent semantic indexing, rough sets, association rules learning and ontologies as a tool for integration. The developed methodology allowed for the creation of semantic knowledge base on the basis of documents in natural language in the field of metallurgy.

Biennial activity report of Metallurgy Division for 1989 and 1990

Energy Technology Data Exchange (ETDEWEB)

Kamachi Mudali, U; Muraleedharan, P; Parameswaran, P; Swaminathan, K; Sreedharan, O M [eds.; Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

1994-12-31

This is the first divisional biennial report of the Metallurgy Division of Indira Gandhi Centre for Atomic Research, for the year 1989-1990, after formation of the Metallurgy Division in September 1988. Major areas of work in the Division relate to aqueous corrosion and localised corrosion, stress corrosion cracking and liquid metal corrosion, high temperature oxidation, thermodynamic studies, physical metallurgy studies for structure-property correlations and failure analyses. The principal materials of studies have been the austenitic stainless steels, the current materials of construction in the Fast Breeder Test Reactor and the candidate materials for the Prototype Fast Breeder Reactor 7 figs., 6 tabs., 2 ills.

Mechanical and microstructural characterization of powder metallurgy CoCrNi medium entropy alloy

Czech Academy of Sciences Publication Activity Database

Moravčík, I.; Čížek, Jan; Kováčová, Z.; Nejezchlebová, J.; Kitzmantel, M.; Neubauer, E.; Kuběna, Ivo; Horník, Vít; Dlouhý, I.

2017-01-01

Roč. 701, July (2017), s. 370-380 ISSN 0921-5093 Institutional support: RVO:61389021 ; RVO:68081723 Keywords : tensile test * mechanical alloying * plastic ity * mechanical characterization * powder metallurgy Subject RIV: JG - Metallurgy; JG - Metallurgy (UFM-A) OBOR OECD: Materials engineering; Materials engineering (UFM-A) Impact factor: 3.094, year: 2016 https://www.sciencedirect.com/science/article/pii/S0921509317308535

Densification of powder metallurgy billets by a roll consolidation technique

Science.gov (United States)

Sellman, W. H.; Weinberger, W. R.

1973-01-01

Container design is used to convert partially densified powder metallurgy compacts into fully densified slabs in one processing step. Technique improves product yield, lowers costs and yields great flexibility in process scale-up. Technique is applicable to all types of fabricable metallic materials that are produced from powder metallurgy process.

Radiation technologies in metallurgy and machinery

International Nuclear Information System (INIS)

Meshkov, I.N.

1990-01-01

Applications of electron beam accelerators for technologies in metallurgy and machinery are discussed. Processes described are provided with special industrial accelerators, developed in the Institute of Nuclear Physics, Novosibirsk. (author)

[Respiratory diseases in metallurgy production workers].

Science.gov (United States)

Shliapnikov, D M; Vlasova, E M; Ponomareva, T A

2012-01-01

The authors identified features of respiratory diseases in workers of various metallurgy workshops. Cause-effect relationships are defined between occupational risk factors and respiratory diseases, with determining the affection level.

A survivability model for ejection of green compacts in powder metallurgy technology

Directory of Open Access Journals (Sweden)

Payman Ahi

2012-01-01

Full Text Available Reliability and quality assurance have become major considerations in the design and manufacture of today’s parts and products. Survivability of green compact using powder metallurgy technology is considered as one of the major quality attributes in manufacturing systems today. During powder metallurgy (PM production, the compaction conditions and behavior of the metal powder dictate the stress and density distribution in the green compact prior to sintering. These parameters greatly influence the mechanical properties and overall strength of the final component. In order to improve these properties, higher compaction pressures are usually employed, which make unloading and ejection of green compacts more challenging, especially for the powder-compacted parts with relatively complicated shapes. This study looked at a mathematical survivability model concerning green compact characteristics in PM technology and the stress-strength failure model in reliability engineering. This model depicts the relationship between mechanical loads (stress during ejection, experimentally determined green strength and survivability of green compact. The resulting survivability is the probability that a green compact survives during and after ejection. This survivability model can be used as an efficient tool for selecting the appropriate parameters for the process planning stage in PM technology. A case study is presented here in order to demonstrate the application of the proposed survivability model.

Research of radiation protection standard system in uranium mining and metallurgy

International Nuclear Information System (INIS)

Lian Guoxi; Song Liquan; Xie Zhanjun

2011-01-01

The contents of radiation and environment protection standards used in uranium mining and metallurgy are analyzed and the existent problems in current standard system are pointed out. A new standard system is established according to theory of systematology and the actuality of uranium mining and metallurgy. Some standard checklists which need to be complemented, corrected, deleted and used during the work of perfection and complementation of standard system are presented. The procedures of establishing new standard system are described, and some suggestions on the establishment and implementation of radiation protection standard system in uranium mining and metallurgy are put forward. (authors)

Foundations of powder metallurgy

International Nuclear Information System (INIS)

Libenson, G.A.

1987-01-01

Consideration is being given to physicochemical foundations and technology of metal powders, moulding and sintering of bars, made of them or their mixtures with nonmetal powders. Data on he design of basic equipment used in the processes of powder metallurgy and its servicing are presented. General requirements of safety engineering when fabricating metal powders and products of them are mentioned

Application of powder metallurgy beryllium in Beijing spectrometer III beam pipe

International Nuclear Information System (INIS)

Zheng Lifang; Li Xunfeng; Wang Li; Ji Quan; Liu Jianping

2008-01-01

According to the requirements of Beijing Spectrometer III (BESIII) beam pipe, the physical properties of several materials were compared and powder metallurgy beryllium was chosen as the material for the central pipe of the BES III beam pipe. Weight-loss method was used to study the corrosion of powder metallurgy beryllium in No. 1 oil for electron discharge machining (EDM-1). The result shows that the anticorrosive property of powder metallurgy beryllium in EDM-1 is high. The corrosion rate, 4.18 x 10 -7 kg· m -2 ·h -1 in initial stage, becomes small with the lapse of the time and stabilizes at 1.54 x 10 -7 kg·m -2 ·h -1 at last. It can be estimated that the powder metallurgy beryllium will be corroded 19.9 μm in the depth in 10 years and it accounts for 3.32% of the smallest thickness of the central pipe, which satisfies the requirements of the BESIII. (authors)

Computational thermodynamics in electric current metallurgy

DEFF Research Database (Denmark)

Bhowmik, Arghya; Qin, R.S.

2015-01-01

. The method has been validated against the analytical solution of current distribution and experimental observation of microstructure evolution. It provides a basis for the design, prediction and implementation of the electric current metallurgy. The applicability of the theory is discussed in the derivations.......A priori derivation for the extra free energy caused by the passing electric current in metal is presented. The analytical expression and its discrete format in support of the numerical calculation of thermodynamics in electric current metallurgy have been developed. This enables the calculation...... of electric current distribution, current induced temperature distribution and free energy sequence of various phase transitions in multiphase materials. The work is particularly suitable for the study of magnetic materials that contain various magnetic phases. The latter has not been considered in literature...

Tungsten and tungsten alloys by powder metallurgy

International Nuclear Information System (INIS)

Belhadjhamida, A.; German, R.M.

1991-01-01

Tungsten has a historical link with powder metallurgy and there is continued progress in expanding the available compositions and processing options. This paper starts with an introduction to the history of tungsten powder metallurgy and use this as a basis for analyzing some of the current trends. The literature base in tungsten processing is expanding and includes new alloys, microstructures, and processing routes. A few examples will be emphasize here to produce a frame work for this program, including description of sintering mechanisms for tungsten, liquid phase sintering advances, hot consolidation fundamentals, and options for complex shaping using powder injection modeling. For this base, subsequent presentations will expand on these fundamental advances

Near-Net Shape Powder Metallurgy Rhenium Thruster

Science.gov (United States)

Leonhardt, Todd; Hamister, Mark; Carlen, Jan C.; Biaglow, James; Reed, Brian

2001-01-01

This paper describes the development of a method to produce a near-net shape (NNS) powder metallurgy (PM) rhenium combustion chamber of the size 445 N (100 lbf) used in a high performance liquid apogee engine. These engines are used in low earth Orbit and geostationary orbit for satellite positioning systems. The developments in near-net shape powder metallurgy rhenium combustion chambers reported in this paper will reduce manufacturing cost of the rhenium chambers by 25 percent, and reduce the manufacturing time by 30 to 40 percent. The quantity of rhenium metal powder used to produce a rhenium chamber is reduced by approximately 70 percent and the subsequent reduction in machining schedule and costs is nearly 50 percent.

Improving the effectiveness of heat use in ferrous metallurgy

Energy Technology Data Exchange (ETDEWEB)

Yegorichev, A P; Lisiyenko, V G; Rozin, S Ye; Shchelokov, Ya M

1980-01-01

Ferrous metallurgy of the USSR consumes about 10% of the total consumption of fuel in the country. The specific consumption of fuel in 100-150-T open-hearth furnaces in the scrap-process flucuate (in kilograms of conventional fuel/T of metal) from 199-206 to 244-249, in 450-T open-hearth furnaces with scrap-ore process from 108 to 135, in method furnaces with step-like beams from 70 to 123, in heating furnaces of low-grade machines ''250'' through 55.4 to 79, and on heating pits of bloomings from 32.5 to 55.3. In openhearth production, the percentage of outlays for fuel is 2.5-4.5%, in rolling 0.6-2% of the net cost of conversion. The overconsumption of fuel up to 5% will increase the net cost of conversion by 0.030.23%. In order to increase the effectiveness of conservation of fuel in ferrous metallurgy, a new method has been proposed for evaluating the energy intensity of the final product of ferrous metallurgy which makes it possible to determine comprehensive energy outlays for the manufactured product. A new system has been developed for stimulating the enterprises of ferrous metallurgy in the struggle for conservation and reduction in the specific consumption norms of fuel. It is based on the establishment of average-sector and progressive standards for single-type units of equal output.

Metallurgical examination of powder metallurgy uranium alloy welds

International Nuclear Information System (INIS)

Morrison, A.G.M.; Dobbins, A.G.; Holbert, R.K.; Doughty, M.W.

1986-01-01

Inertia welding provided a successful technique for joining full density, powder metallurgy uranium-6 wt pct niobium alloy. Initial joining attempts concentrated on the electron beam method, but this method failed to produce a sound weld. The electron beam welds and the inertia welds were evaluated by radiography and metallography. Electron beam welds were attempted on powder metallurgy plates which contained various levels of oxygen and nitrogen. All welds were porous. Sixteen inertia welds were made and all welds were radiographically sound. The tensile properties of the joints were found to be equivalent to the p/m base metal properties

Metallurgy and properties of plasma spray formed materials

Science.gov (United States)

Mckechnie, T. N.; Liaw, Y. K.; Zimmerman, F. R.; Poorman, R. M.

1992-01-01

Understanding the fundamental metallurgy of vacuum plasma spray formed materials is the key to enhancing and developing full material properties. Investigations have shown that the microstructure of plasma sprayed materials must evolve from a powder splat morphology to a recrystallized grain structure to assure high strength and ductility. A fully, or near fully, dense material that exhibits a powder splat morphology will perform as a brittle material compared to a recrystallized grain structure for the same amount of porosity. Metallurgy and material properties of nickel, iron, and copper base alloys will be presented and correlated to microstructure.

Galician mining and metallurgy in the light of the General Regional Exhibition of Lviv in 1894

Directory of Open Access Journals (Sweden)

Wojciech Paduchowski

2014-12-01

Full Text Available The General Regional Exhibition of Lviv was organized in 1894, on the 100 year anniversary of the Kosciuszko Uprising of 1794. The Exhibition was meant to demonstrate Galicia’s economical and cultural progress since its gaining political autonomy and to become an opportunity for the national integration of Poles. The Exhibition displays included various thematic groups which were devoted to both spiritual and material aspects of life in Galicia and were meant to show the abundance of its crops and produce, mining and metallurgy, agriculture, forestry and hunting. The shows pictured everyday life of the inhabitants of Galicia, its folk art, so-called domestic industry and craftwork. Other sections of the Exhibition demonstrated the development of the Galician financial institutions, public administration, healthcare, communication, engineering, construction, literature, general and vocational education and the bloom of the fine arts and architecture. The article analyzes only some parts of the great legacy of the Exhibition, its scope focuses on mining and metallurgy. The text points out the dynamic development of the oil industry and the increase in the branches such as: salt production, iron smelting, and brown and hard coal extraction. The only branch of the Galicia’s economy which had not offered good perspectives and was thus soon discontinued had been the production of earthwax (ozocerite. The organization of the exhibitions of such sort was regarded at that time as one of the best ways to stimulate economy and benefit the regions. The actual development itself, especially of the oil mining, aided many positive social and cultural changes and undoubtedly increased the societal potential and might have resulted in further initiatives.

Development of processes for zircaloy chips recycling by electric arc furnace remelting and powder metallurgy

International Nuclear Information System (INIS)

Pereira, Luiz Alberto Tavares

2014-01-01

PWR reactors employ, as nuclear fuel, UO 2 pellets with Zircaloy clad. In the fabrication of fuel element parts, machining chips from the alloys are generated. As the Zircaloy chips cannot be discarded as ordinary metallic waste, the recycling of this material is important for the Brazilian Nuclear Policy, which targets the reprocess of Zircaloy residues for economic and environmental aspects. This work presents two methods developed in order to recycle Zircaloy chips. In one of the methods, Zircaloy machining chips were refused using an electric-arc furnace to obtain small laboratory ingots. The second one uses powder metallurgy techniques, where the chips were submitted to hydriding process and the resulting material was milled, isostatically pressed and vacuum sintered. The ingots were heat-treated by vacuum annealing. The microstructures resulting from both processing methods were characterized using optical and scanning electron microscopy. Chemical composition, crystal phases and hardness were also determined. The results showed that the composition of recycled Zircaloy comply with the chemical specifications and presented adequate microstructure for nuclear use. The good results of the powder metallurgy method suggest the possibility of producing small parts, like cladding end-caps, using near net shape sintering. (author)

Powder-Metallurgy Process And Product

Science.gov (United States)

Paris, Henry G.

1988-01-01

Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

Summarizing of new techniques in uranium mining and metallurgy

International Nuclear Information System (INIS)

Wang Delin; Zhang Fei; Su Yanru; Zeng Yijun; Meng Jin

2010-01-01

According to character of national resources and uranium mining and metallurgical science and technology members research achievements, new techniques in ten scientific research area of in-situ leaching, heap leaching, multi-metal comprehensive recovery, bio-metallurgy etc. for 10 years is introduced in this paper. The level of innovation ability is shown by technical index, resources recovery and reduction capital cost etc. datum. The application bound of natural uranium resource is enlarged and production ability of national uranium is increased. It is put forward renovation and development ideas for uranium mining and metallurgy. (authors)

Reuse of scrap of Al and steel SAE 1045 in metal composite as alternative of recycling route powder metallurgy

International Nuclear Information System (INIS)

Souza, V.E.S.; Masieiro, F.R.S.; Lourenco, J.M.; Felipe, R.C.T.S.

2009-01-01

Full text: The process of powder metallurgy in the production of parts through application of pressure on the selected ceramic or metal powders, which are subjected to a temperature of sintering for to occur consolidation of the components. The metal-mechanical industry is responsible for the generation of inputs from their manufacturing processes. This work aims to re-use of chips of Al and SAE 1045 steel by powder metallurgy of this is a viable and effective. This work is in the manufacture of a composite using Al 6060 metal matrix and steel 1045 as reinforcement (30%, 40%, 50%), under different compaction pressures (250MPa, 400MPa and 600MPa), analyzing the influence of compressibility in hardness of the compressed. The samples were sintered at a temperature of 500 ° C in an oven using resistive atmosphere of hydrogen for 45 minutes. After the procedures of the powder metallurgy technique were analyzed of the optical microscopy, x-ray diffraction, MEV and Rockwell hardness, which was found to be evaluated as not diffusibility between the steel and aluminum. (author)

Make new contribution to the development of uranium mining and metallurgy in 21ST century, based on scientific and technological progresses

International Nuclear Information System (INIS)

Wang Delin

2000-01-01

The key project of national defense and nuclear energy, study on new techniques of uranium ore mining and uranium extraction, undertaken by Beijing Research Institute of Chemical Engineering and Metallurgy, and its main scientific research achievements during the 9th Five-year Plan are briefly introduced. Aim and tasks of work during the 10th Five-year Plan are determined

Metallurgy department publications and lectures 1987

International Nuclear Information System (INIS)

Schroeder Pedersen, A.; Bilde-Soerensen, J.B.

1988-04-01

A presentation (including abstract) of scientific and technical publications and lectures by the staff of the Metallurgy Department during 1987 is given. The list comprises journal papers, conference papers, reports, lectures and poster presentations in the following categories: Publications, Lectures and Poster Presentations. (author)

A Comparison of the Plastic Flow Response of a Powder Metallurgy Nickel Base Superalloy (Postprint)

Science.gov (United States)

2017-04-01

AFRL-RX-WP-JA-2017-0225 A COMPARISON OF THE PLASTIC-FLOW RESPONSE OF A POWDER- METALLURGY NICKEL-BASE SUPERALLOY (POSTPRINT) S.L...COMPARISON OF THE PLASTIC-FLOW RESPONSE OF A POWDER- METALLURGY NICKEL-BASE SUPERALLOY (POSTPRINT) 5a. CONTRACT NUMBER IN-HOUSE 5b. GRANT...behavior at hot-working temperatures and strain rates of the powder- metallurgy superalloy LSHR was determined under nominally-isothermal and transient

Nuclear science and metallurgy. Advances and interactions

Energy Technology Data Exchange (ETDEWEB)

Grison, E [CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1977-01-01

The history of the production of atomic power by fission since 1953 is reviewed: metallurgy of uranium; the new metals zirconium and beryllium; steels and nuclear structure; nuclear reactor vessels; water corrosion; effects of radiations.

Effect of vanadium carbide on dry sliding wear behavior of powder metallurgy AISI M2 high speed steel processed by concentrated solar energy

Energy Technology Data Exchange (ETDEWEB)

García, C. [Materials Engineering. E.I.I., Universidad de Valladolid. C/Paseo del cauce 59, 47011 Valladolid (Spain); Romero, A. [E.T.S. Ingenieros Industriales. Instituto de Investigaciones Energéticas y Aplicaciones Industriales (INEI). Universidad de Castilla-La Mancha, Edificio Politécnico, Avda. Camilo José Cela s/n, 13071 Ciudad Real (Spain); Herranz, G., E-mail: gemma.herranz@uclm.es [E.T.S. Ingenieros Industriales. Instituto de Investigaciones Energéticas y Aplicaciones Industriales (INEI). Universidad de Castilla-La Mancha, Edificio Politécnico, Avda. Camilo José Cela s/n, 13071 Ciudad Real (Spain); Blanco, Y.; Martin, F. [Materials Engineering. E.I.I., Universidad de Valladolid. C/Paseo del cauce 59, 47011 Valladolid (Spain)

2016-11-15

Mixtures of AISI M2 high speed steel and vanadium carbide (3, 6 or 10 wt.%) were prepared by powder metallurgy and sintered by concentrated solar energy (CSE). Two different powerful solar furnaces were employed to sinter the parts and the results were compared with those obtained by conventional powder metallurgy using a tubular electric furnace. CSE allowed significant reduction of processing times and high heating rates. The wear resistance of compacts was studied by using rotating pin-on-disk and linearly reciprocating ball-on-flat methods. Wear mechanisms were investigated by means of scanning electron microscopy (SEM) observations and chemical inspections of the microstructures of the samples. Better wear properties than those obtained by conventional powder metallurgy were achieved. The refinement of the microstructure and the formation of carbonitrides were the reasons for this. - Highlights: •Powder metallurgy of mixtures of M2 high speed steel and VC are studied. •Some sintering is done by concentrated solar energy. •Rotating pin-on-disk and linearly reciprocating ball-on-flat methods are used. •The tribological properties and wear mechanisms, under dry sliding, are studied.

Nuclear science and metallurgy. Advances and interactions

International Nuclear Information System (INIS)

Grison, Emmanuel

1977-01-01

The history of the production of atomic power by fission since 1953 is reviewed: metallurgy of uranium; the new metals zirconium and beryllium; steels and nuclear structure; nuclear reactor vessels; water corrosion; effects of radiations [fr

Precipitation in Powder Metallurgy, Nickel Base Superalloys: Review of Modeling Approach and Formulation of Engineering (Postprint)

Science.gov (United States)

2016-12-01

AFRL-RX-WP-JA-2016-0333 PRECIPITATION IN POWDER- METALLURGY , NICKEL-BASE SUPERALLOYS: REVIEW OF MODELING APPROACH AND FORMULATION OF...PRECIPITATION IN POWDER- METALLURGY , NICKEL- BASE SUPERALLOYS: REVIEW OF MODELING APPROACH AND FORMULATION OF ENGINEERING (POSTPRINT) 5a...and kinetic parameters required for the modeling of γ′ precipitation in powder- metallurgy (PM), nickel-base superalloys are summarized. These

Photometric determination of trace cadmium in waste water drained from uranium mining and water-metallurgy

International Nuclear Information System (INIS)

Zhu Zihui; Gu Gang; Xu Quanxiu

1987-09-01

Cadmium (Cd) ions react with dithizone to form a pink to red color that can be extracted with chloroform and measured photometrically. Dithizone method is one of standard method to determine trace Cd in the environmental waste water. This method, however, can not be suitable for measuring the trace Cd in the waste water drained from uranium mining and water-metallurgy factory, because this kind of waste water contains magnesium ions as high as 1500 mg/L. One more discomfort is that the method needs to use a large amount of potassium cyanide. The authors, therefore, used potassium fluorine as a precipitator that removed the excess magnesium ions in the experimental system, and try to reduce the amount of potassium cyanide to 1/20 of original usage. The experimental results indicated that the modified method as mentioned above was very satisfactory either to simulated samples or to actual samples of waste water drained from uranium mining and water-metallurgy plants. In Summary, this modified method has higher sensitivity with minimun detectable quantity of 0.02 ppm and it is accurate and reproducible with recovery rate of 100 ± 5%

The metallurgy, science and engineering

International Nuclear Information System (INIS)

Pineau, A.; Quere, Y.

2011-01-01

Metallurgy, the science of metals and the technical discipline concerned with the production, shaping and assembling of metals, is one of the major assets of European economy. The French metallurgy industry - from producers (steel, light alloys, ...) to users (car, aviation, nuclear industries, ...) -- has achieved in many of its sectors a world-class level of excellence, based on high-quality research centres that are recognized both for their theoretical and experimental academic work. By contrast, public research is insufficiently concerned with engineering. In 2004, this industry employed 1 800 000 persons, 220 000 of which worked as engineers and managers in 45 000 companies, with a turnover of 420 billion euros. This state of grace is starting to decline. We are undergoing, in this sector as in others, a de-industrialization that affects upstream activities: courses in these disciplines, which have been previously outstanding, have partially disappeared; laboratories have shrunk; expertise has been dispersed; students are staying away from a discipline they consider 'unfruitful', like many other engineering sciences. Simultaneously, further up in this sector, decision centres have moved away from production centres and away from our country. France still maintains a few important R and D centres within international groups in spite of France's decreasing weight in world production. However, these groups see the future of R and D as being centred in the emerging countries (China, India...). The main users (transport, energy, ...) are losing their experts as are the technical centres on which rely a large network of small and medium businesses. The consequences are alarming in view of the already noticeable loss of technical control. This trend can and must be reversed. Because of its presence in many industrial sectors and its excellence, metallurgy - including both research and industry - is an essential activity in which France should remain a major player

Microstructure and corrosion of Pd-modified Ti alloys produced by powder metallurgy

International Nuclear Information System (INIS)

Ashworth, M.A.; Davenport, A.J.; Ward, R.M.; Hamilton, H.G.C.

2010-01-01

A method for the fabrication of titanium alloy parts with enhanced corrosion resistance by a powder metallurgy route is presented in this paper. Commercial purity titanium powders modified with Pd have been hot isostatically pressed (HIPped) and the microstructure and distribution of the noble metal characterised by optical and scanning electron microscopy. The electrochemistry of the HIPped alloy has been assessed and the effect of powder size fraction evaluated. Results show that the phase composition and electrochemistry of the HIPped Pd-modified alloy is equivalent to that of wrought grade 7 Ti.

Summary of NRC LWR safety research programs on fuel behavior, metallurgy/materials and operational safety

International Nuclear Information System (INIS)

Bennett, G.L.

1979-09-01

The NRC light-water reactor safety-research program is part of the NRC regulatory program for ensuring the safety of nuclear power plants. This paper summarizes the results of NRC-sponsored research into fuel behavior, metallurgy and materials, and operational safety. The fuel behavior research program provides a detailed understanding of the response of nuclear fuel assemblies to postulated off-normal or accident conditions. Fuel behavior research includes studies of basic fuel rod properties, in-reactor tests, computer code development, fission product release and fuel meltdown. The metallurgy and materials research program provides independent confirmation of the safe design of reactor vessels and piping. This program includes studies on fracture mechanics, irradiation embrittlement, stress corrosion, crack growth, and nondestructive examination. The operational safety research provides direct assistance to NRC officials concerned with the operational and operational-safety aspects of nuclear power plants. The topics currently being addressed include qualification testing evaluation, fire protection, human factors, and noise diagnostics

Metallurgy for nuclear engineering

International Nuclear Information System (INIS)

Kozlov, A.F.

1986-01-01

Principal ways of development in metallurgy and metallurgical equipment on nuclear engineering plants are discussed. A great attention is paid to changing welded structures for casted and forged ones. These measures give the possibility to increase reliability of NPP components and decrease labour content. The following processing procedures have been introduced: vacuum carbon reduction providing small amount of nonmetallic inclusions in reactor vessel steel; manufacturing steel large-size castings (360 and 420 t) for WWER vessels; rolling at plate mill 5000 etc

Physical metallurgy of titanium alloys

International Nuclear Information System (INIS)

Collings, E.W.

1988-01-01

Researches in electric, magnetic, thermophysical properties of titanium alloys in the wide range of temperatures (from helium upto elevated one), as well as stability of phases in alloys of different types are generalized. Fundamental description of physical properties of binary model alloys is given. Acoustic emission, shape memory and Bauschinger effects, pseudoelasticity, aging and other aspects of physical metallurgy of titanium alloys are considered

Metallurgy of steels for PWR pressure vessels

International Nuclear Information System (INIS)

Kepka, M.; Mocek, J.; Barackova, L.

1980-01-01

A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure. (B.S.)

Metallurgy of steels for PWR pressure vessels

Energy Technology Data Exchange (ETDEWEB)

Kepka, M; Mocek, J; Barackova, L [Skoda, Plzen (Czechoslovakia)

1980-09-01

A survey and the chemical compositions are presented of reactor pressure vessel steels. The metallurgy is described of steel making for pressure vessels in Japan and the USSR. Both acidic and alkaline open-hearth steel is used for the manufacture of ingots. The leading world manufacturers of forging ingots for pressure vessels, however, exclusively use electric steel. Vacuum casting techniques are exclusively used. Experience is shown gained with the introduction of the manufacture of forging ingots for pressure vessels at SKODA, Plzen. The metallurgical procedure was tested utilizing alkaline open hearths, electric arc furnaces and facilities for vacuum casting of steel. Pure charge raw materials should be used for securing high steel purity. Prior to forging pressure vessel rings, not only should sufficiently big bottoms and heads be removed but also the ingot middle part should be scrapped showing higher contents of impurities and nonhomogeneous structure.

Microstructural and electrical investigation of Cu-Ni-Cr alloys obtained by powder metallurgy method

International Nuclear Information System (INIS)

Carrio, Juan A.G.; Carvalhal, M.A.; Ayabe, L.M.; Monteiro, W.A.

2009-01-01

The aim of this work, using the powder metallurgy process, is to synthesize metallic alloys with high mechanical strength and high electric conductivity, after melting optimizing and thermal treatments. The Cu-Ni-Cr (wt%) alloys are characterized in their mechanical and electrical properties as well as the obtained microstructure. Through the process of powder metallurgy, contacts and structural parts can be obtained. The alloys elements are added to copper with the intention to improve their strength, ductility and thermal stability, without causing considerable damages in their form, electrical and thermal conductivity, and corrosion resistance. The metallic powders were mixed for a suitable time and then they were pressed in a cold uniaxial pressing (1000 kPa). Afterwards, the specimens were sintered in temperatures varying from 700 up to 800 deg C under vacuum. At last, the samples were homogenized at 550 deg C under vacuum, for special times. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples. The alloys were characterized by optical microscopy, X-rays powder diffraction, electrical conductivity and Vickers hardness. (author)

Uranium mining and metallurgy library information service under the network environment

International Nuclear Information System (INIS)

Tang Lilei

2012-01-01

This paper analyzes the effect of the network environment on the uranium mining and metallurgy of the information service. Introduces some measures such as strengthening professional characteristic literature resources construction, changing the service mode, building up information navigation, deepening service, meet the individual needs of users, raising librarian's quality, promoting the co-construction and sharing of library information resources, and puts forward the development idea of uranium mining and metallurgy library information service under the network environment. (author)

Powder metallurgy bearings for advanced rocket engines

Science.gov (United States)

Fleck, J. N.; Killman, B. J.; Munson, H.E.

1985-01-01

Traditional ingot metallurgy was pushed to the limit for many demanding applications including antifriction bearings. New systems require corrosion resistance, better fatigue resistance, and higher toughness. With conventional processing, increasing the alloying level to achieve corrosion resistance results in a decrease in other properties such as toughness. Advanced powder metallurgy affords a viable solution to this problem. During powder manufacture, the individual particle solidifies very rapidly; as a consequence, the primary carbides are very small and uniformly distributed. When properly consolidated, this uniform structure is preserved while generating a fully dense product. Element tests including rolling contact fatigue, hot hardness, wear, fracture toughness, and corrosion resistance are underway on eleven candidate P/M bearing alloys and results are compared with those for wrought 440C steel, the current SSME bearing material. Several materials which offer the promise of a significant improvement in performance were identified.

Development and application of characteristic database for uranium mining and metallurgy in the library of Beijing Research Institute of Chemical Engineering and Metallurgy

International Nuclear Information System (INIS)

Gao Renxi

2012-01-01

Beijing Research Institute of Chemical Engineering and Metallurgy (BRICEM) is a multi disciplinary comprehensive research institute engaged in uranium mining, engineering design and related material researches. After 53 years of researches and development, BRICEM has accumulated a plenty of valuable data and resources. By analyzing the actual conditions of BRICEM's technological database, this thesis aims to propose the idea of building a characteristic database for uranium mining and metallurgy. It gives an in-depth analysis on content design, development status and problems of database development, in order to come up with solutions to these problems, as well as suggestions on the future development plans of the characteristic database. (author)

Machinability of zinc-aluminum alloy5; zamzk5; alloy produced by powder metallurgy

International Nuclear Information System (INIS)

Adnan, I.O.; Momani, M.A.A.

2007-01-01

Powder metallurgy process (P/M) is repeatedly reported as a near-net or net-shape manufacturing process with the ability of producing parts of complicated or intricate shapes with high required dimensional accuracy and high surface quality. However, some finishing and machining operations are sometimes necessary and must be done to meet dimensional tolerances or accommodate design features that can be achieved during compaction such as transverse holes, undercuts and threads. Therefore, it is necessary to study the machinability of P/M products. ZAMAK5 alloy is widely used in engineering applications in the automobile industry, particularly in the manufacturing of bushes and recently self -lubricated bearings which are manufactured by the P/M process. Therefore it is anticipated that studying the machinability of this alloy as produced by the powder metallurgy process is worthwhile investigating. In this paper, the machinability of ZAMAK5, alloy produced by powder metallurgy, under different cutting conditions of speed, depth of cut and feed rate is carried out. Surface roughness was used as a criterion for assessing machinability at the different conditions. It was found that specimens compacted at 475 MPa and having 1% addition of zinc stearates as a binder and lubricant gave better surface quality than those produced at 550 MPa compacting pressure,whereas at 1.5% addition of zinc stearates produced worse surface quality (i.e. Higher surface roughness than in case of 475 MPa compacting pressure). On the whole, the results of the experimental work revealed that the surface roughness at the different cutting conditions remained within the accepted level in industry, less than 2 microns. (author)

Plutonium metallurgy: The materials science challenges bridging condensed-matter physics and chemistry

Energy Technology Data Exchange (ETDEWEB)

Schwartz, A.J. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)], E-mail: schwartz6@llnl.gov

2007-10-11

Although there exists evidence of metallurgical practices dating back over 6000 years, studies of Pu and Pu alloys have been conducted for barely 60 years. During the time of the Manhattan Project and extending for some time afterward, the priority to produce the metal took precedence over the fundamental understanding of the metallurgical principals. In the past decade or so, there has been a resurgence in the basic metallurgy, condensed-matter physics, and chemistry of Pu and Pu alloys. These communities have made substantial progress, both experimentally and theoretically in many areas; however, many challenges still remain. The intent of this brief overview is to highlight a number important challenges that we face in the metallurgy of Pu including phase transformations and phase stability, aging, and the connection between electronic structure and metallurgy.

Metallurgy - steel and non-ferrous metals

International Nuclear Information System (INIS)

Wusatowski, R.

1999-01-01

Several actual problems of metallurgy and processing of the chief metals and their alloys, especially of steel, copper, zinc and aluminium were discussed. The thought was given to the problems of: scientific, technical (also the energy consumption of production, the evolution of technology), organizational, economical, even political nature (influence of the state on the development of industry). (author)

Fast neutron activation analysis in metallurgy

International Nuclear Information System (INIS)

Sterlinski, S.

1981-01-01

Article discusses the usage of a 14 MeV neutron generator for producing fast neutrons of different energies and intensities. A complete instrumental set-up for the neutron activation analysis (NAA) is given. In metallurgy the device is mainly used in the determination of oxygen and silicon in steel and non-ferrous metal, including different alloys

Neutrons in the field of metallurgy

International Nuclear Information System (INIS)

Novion, C. de

1989-01-01

Beams of thermal neutrons are now widely used for the study of material structure. Following a summary of the characteristics of the neutron-material interaction, and an outlook on the major uses of neutrons in metallurgy, we present some examples of application. The comparative advantages and drawbacks of neutrons and X-rays are discussed. 14 refs [fr

Development and characterization of Al-Zn alloy by ingot metallurgy and powder metallurgy with improved mechanical properties

International Nuclear Information System (INIS)

Waseem, M.; Awais, H.B.; Zauha, M.S.; Tariq, N.H.

2007-01-01

Current project focuses on the production of AI-Zn alloy AA7075 used for wide range of applications like Aircraft components, missile and other structural applications. The above alloy was developed by two different routes. One was melting /casting, after which alloy was characterized by microstructural - examination (optical and SEM) and mechanical testing. Other route was the preparation of this alloy by powder metallurgy. This involves preparation of powders, mechanical alloying, compaction, sintering, rolling, solution treatment and aging then analysis. Powders of Aluminum, Zinc and powders of master alloys of AI-Cu, AI-Mg, AI-Mn, and AI-Cr were Mechanical alloyed. Then this powder was compacted by uniaxial press to form pellets. Sintering was carried out at 500 degree C and then hot rolled in Ar atmosphere. After solution and aging treatments samples were characterized. It is observed that there is about 12-21% improvement in mechanical properties such as tensile strength, yield strength, ductility and fracture toughness due to the more fine microstructure and less segregation than ingot metallurgy route. (author)

CURRENT STATE AND TENDENCIES OF DEVELOPMENT OF FERROUS METALLURGY IN THE EAEU COUNTRIES

Directory of Open Access Journals (Sweden)

N. P. Dragun

2016-01-01

Full Text Available The analysis of modern status and tendencies of development of ferrous metallurgy in the countries of the EAEU is described in the article. On the basis of the conducted analysis are revealed the identified systemic problems of metallurgy and the conclusions on possible ways of their solution using the potential of integration are given.

Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces

International Nuclear Information System (INIS)

Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

2014-01-01

This paper shows the different types of furnaces for roasting cinnabar, used in the metallurgy of quicksilver over the centuries of exploitation of the Almaden Mines (Spain). Some of these techniques are part of our industrial heritage. They have contributed to name UNESCO World Heritage Site the vast technological legacy of these mines recently. This research contributes to close the long way of metallurgical activity from aludel furnaces until Pacif furnaces, first and lasted technology to produce on an industrial scale. It is delved into the most relevant aspects having to do with the type, evolution and number of furnaces existing on each of the periods. (Author)

Physical and welding metallurgy of Gd-enriched austenitic alloys for spent nuclear fuel applications. Part II, nickel base alloys

International Nuclear Information System (INIS)

Mizia, Ronald E.; Michael, Joseph Richard; Williams, David Brian; Dupont, John Neuman; Robino, Charles Victor

2004-01-01

The physical and welding a metallurgy of gadolinium- (Gd-) enriched Ni-based alloys has been examined using a combination of differential thermal analysis, hot ductility testing. Varestraint testing, and various microstructural characterization techniques. Three different matrix compositions were chosen that were similar to commercial Ni-Cr-Mo base alloys (UNS N06455, N06022, and N06059). A ternary Ni-Cr-Gd alloy was also examined. The Gd level of each alloy was ∼2 wt-%. All the alloys initiated solidification by formation of primary austenite and terminated solidification by a Liquid γ + Ni 5 Gd eutectic-type reaction at ∼1270 C. The solidification temperature ranges of the alloys varied from ∼100 to 130 C (depending on alloy composition). This is a substantial reduction compared to the solidification temperature range to Gd-enriched stainless steels (360 to 400 C) that terminate solidification by a peritectic reaction at ∼1060 C. The higher-temperature eutectic reaction that occurs in the Ni-based alloys is accompanied by significant improvements in hot ductility and solidification cracking resistance. The results of this research demonstrate that Gd-enriched Ni-based alloys are excellent candidate materials for nuclear criticality control in spent nuclear fuel storage applications that require production and fabrication of large amounts of material through conventional ingot metallurgy and fusion welding techniques

Progress in vacuum metal extraction, refining and consolidation

International Nuclear Information System (INIS)

Sundaram, C.V.; Mukherjee, T.K.; Sharma, B.P.

1973-01-01

The unique achievements in the process metallurgy of rare metals in the past quarter century should largely be attributed to advances in vacuum technology. New standards for high purity, increasing demand for pure metals and alloys for established applications, and steady improvement in sophistication and capacity of vacuum furnaces have provided the stimulus for developing and expanding vacuum metal extraction processes, and also exploring totally new processes. The paper discusses the thermochemistry of vacuum metallurgy, carbothermic and metallothermic reduction reactions, consolidation and refining by vacuum arc melting, electron beam melting and high temperature high vacuum sintering, and ultrapurification, with special reference to the reactive and refractory metals of Group IV to VI. (author)

Laser photothermal non-destructive metrology of cracks in un-sintered powder metallurgy manufactured automotive transmission sprockets

International Nuclear Information System (INIS)

Tolev, J; Mandelis, A

2010-01-01

A non-contact and non-intrusive method of revealing crack presence in un-sintered (green) automotive transmission parts (sprockets), manufactured by means of a powder metallurgy technology based on analysis of photo-thermal radiometric (PTR) signals and their statistical analysis was developed. The inspection methodology relies on the interaction of a modulated laser generated thermal wave with the potential crack and the resulting change in amplitude and phase of the detected signal [1-5]. The crack existence at points in high stress regions of a group of green (unsintered) sprockets was evaluated through frequency scans. The results were validated by independent destructive cross-sectioning of the sprockets following sintering and polishing. Examination of the sectioned sprockets under a microscope at the locations where signal changes was used for correlation with the PTR signals. Statistical analysis confirmed the capabilities of the method to detect the presence of hairline cracks (∼5 - 10 μm size) with excellent sensitivity (91%) and good accuracy (78%) and specificity (61%). This measurement technique and the associated statistical analysis can be used as a simple and reliable on-line inspection methodology of industrial powder metallurgy manufactured steel products for non-destructive quality and feedback control of the parts forming process.

A Novel Process for Joining Ti Alloy and Al Alloy using Two-Stage Sintering Powder Metallurgy

Science.gov (United States)

Long, Luping; Liu, Wensheng; Ma, Yunzhu; Wu, Lei; Liu, Chao

2018-04-01

The major challenges for conventional diffusion bonding of joining Ti alloy and Al alloy are the undesirable interfacial reaction, low matrixes and joint strength. To avoid the problem in diffusion bonding, a novel two-stage sintering powder metallurgy process is developed. In the present work, the interface characterization and joint performance of the bonds obtained by powder metallurgy bonding are investigated and are compared with the diffusion bonded Ti/Al joints obtained with the same and the optimized process parameters. The results show that no intermetallic compound is visible in the Ti/Al joint obtained by powder metallurgy bonding, while a new layer formed at the joint diffusion bonded with the same parameters. The maximum tensile strength of joint obtained by diffusion bonding is 58 MPa, while a higher tensile strength reaching 111 MPa for a bond made by powder metallurgy bonding. Brittle fractures occur at all the bonds. It is shown that the powder metallurgy bonding of Ti/Al is better than diffusion bonding. The results of this study should benefit the bonding quality.

Application of laser in powder metallurgy

International Nuclear Information System (INIS)

Tolochko, N.K.

1995-01-01

Modern status of works in the field of laser application in powder metallurgy (powders preparation, sintering, coatings formation, powder materials processing) is considered. The attention is paid to the new promising direction in powder products shape-formation technology - laser layer-by-layer selective powders sintering and bulk sintering of packaged layered profiles produced by laser cutting of powder-based sheet blanks. 67 refs

The Effect of Forging Variables on the Supersolvus Heat-Treatment Response of Powder-Metallurgy Nickel-Base Superalloys

Science.gov (United States)

2014-12-01

AFRL-RX-WP-JA-2015-0160 THE EFFECT OF FORGING VARIABLES ON THE SUPERSOLVUS HEAT-TREATMENT RESPONSE OF POWDER - METALLURGY NICKEL-BASE SUPERALLOYS... POWDER - METALLURGY NICKEL- BASE SUPERALLOYS (POSTPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6. AUTHOR...treatment (SSHT) of two powder - metallurgy , gamma–gamma prime superalloys, IN-100 and LSHR, was established. For this purpose, isothermal, hot

Nuclear-technical applications in gold extraction metallurgy

International Nuclear Information System (INIS)

Smith, S.W.; De Jesus, A.S.M.

1986-01-01

Radioisotopes have been used for a number of years by the South African gold mining industry in a variety of measuring techniques, not only in conventional on-line process instrumentation, but also to investigate problem areas in extraction processes. These include, inter alia, tracer investigations on recirculating underground water, measurement of air ventilation rates in a mine, residence time measurements in milling and leaching circuits, and gold purity determinations. Applications of both sealed sources and radioactive tracer techniques are reviewed by means of examples of work done in South Africa, with pertinent reference to the benefits accruing to the gold mining industry

Fabrication of metal matrix composites by powder metallurgy: A review

Science.gov (United States)

Manohar, Guttikonda; Dey, Abhijit; Pandey, K. M.; Maity, S. R.

2018-04-01

Now a day's metal matrix components are used in may industries and it finds the applications in many fields so, to make it as better performable materials. So, the need to increase the mechanical properties of the composites is there. As seen from previous studies major problem faced by the MMC's are wetting, interface bonding between reinforcement and matrix material while they are prepared by conventional methods like stir casting, squeeze casting and other techniques which uses liquid molten metals. So many researchers adopt PM to eliminate these defects and to increase the mechanical properties of the composites. Powder metallurgy is one of the better ways to prepare composites and Nano composites. And the major problem faced by the conventional methods are uniform distribution of the reinforcement particles in the matrix alloy, many researchers tried to homogeneously dispersion of reinforcements in matrix but they find it difficult through conventional methods, among all they find ultrasonic dispersion is efficient. This review article is mainly concentrated on importance of powder metallurgy in homogeneous distribution of reinforcement in matrix by ball milling or mechanical milling and how powder metallurgy improves the mechanical properties of the composites.

Industrial powder metallurgy processing for production of high field Nb3Sn

International Nuclear Information System (INIS)

Hecker, A.; Gregory, E.; Wong, J.; Thieme, C.L.H.; Foner, S.

1988-01-01

Technology transfer is discussed for fabricating Nb 3 Sn(Ti) via powder metallurgy methods from laboratory scale production at MIT to industrial production at Supercon Inc. Industrial production techniques such as hydrostatic extrusion and drawing have produced superconducting wires with promising critical current densities in preliminary field measurements. Initial steps toward process modification and optimization to improve the commercial feasibility of the powder metallurgy process are evaluated. These modifications are aimed at reducing production time and increasing process flexibility

[Atmospheric emission of PCDD/Fs from secondary aluminum metallurgy industry in the southwest area, China].

Science.gov (United States)

Lu, Yi; Zhang, Xiao-Ling; Guo, Zhi-Shun; Jian, Chuan; Zhu, Ming-Ji; Deng, Li; Sun, Jing; Zhang, Qin

2014-01-01

Five secondary aluminum metallurgy enterprises in the southwest area of China were measured for emissions of PCDD/Fs. The results indicated that the emission levels of PCDD/Fs (as TEQ) were 0.015-0.16 ng x m(-3), and the average was 0.093 ng x m(-3) from secondary aluminum metallurgy enterprises. Emission factors of PCDD/Fs (as TEQ) from the five secondary aluminum metallurgy enterprises varied between 0.041 and 4.68 microg x t(-1) aluminum, and the average was 2.01 microg x t(-1) aluminum; among them, PCDD/Fs emission factors from the crucible smelting furnace was the highest. Congener distribution of PCDD/F in stack gas from the five secondary aluminum metallurgies was very different from each other. Moreover, the R(PCDF/PCDD) was the lowest in the enterprise which was installed only with bag filters; the R(PCDF/PCDD) were 3.8-12.6 (the average, 7.7) in the others which were installed with water scrubbers. The results above indicated that the mechanism of PCDD/Fs formation was related to the types of exhaust gas treatment device. The results of this study can provide technical support for the formulation of PCDD/Fs emission standards and the best available techniques in the secondary aluminum metallurgy industry.

Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago

Science.gov (United States)

Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Rehren, Th.; Schwikowski, M.

2017-01-01

The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

Ice-core evidence of earliest extensive copper metallurgy in the Andes 2700 years ago.

Science.gov (United States)

Eichler, A; Gramlich, G; Kellerhals, T; Tobler, L; Rehren, Th; Schwikowski, M

2017-01-31

The importance of metallurgy for social and economic development is indisputable. Although copper (Cu) was essential for the wealth of pre- and post-colonial societies in the Andes, the onset of extensive Cu metallurgy in South America is still debated. Comprehensive archaeological findings point to first sophisticated Cu metallurgy during the Moche culture ~200-800 AD, whereas peat-bog records from southern South America suggest earliest pollution potentially from Cu smelting as far back as ~2000 BC. Here we present a 6500-years Cu emission history for the Andean Altiplano, based on ice-core records from Illimani glacier in Bolivia, providing the first complete history of large-scale Cu smelting activities in South America. We find earliest anthropogenic Cu pollution during the Early Horizon period ~700-50 BC, and attribute the onset of intensified Cu smelting in South America to the activities of the central Andean Chiripa and Chavin cultures ~2700 years ago. This study provides for the first time substantial evidence for extensive Cu metallurgy already during these early cultures.

Powder-metallurgy preparation of NiTi shape-memory alloy using mechanical alloying and spark-plasma sintering.

Czech Academy of Sciences Publication Activity Database

Novák, P.; Moravec, H.; Vojtěch, V.; Knaislová, A.; Školáková, A.; Kubatík, Tomáš František; Kopeček, Jaromír

2017-01-01

Roč. 51, č. 1 (2017), s. 141-144 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:61389021 ; RVO:68378271 Keywords : mechanical alloying * spark plasma sintering * NiTi * shape memory alloy Subject RIV: JG - Metallurgy; JG - Metallurgy (FZU-D) OBOR OECD: Materials engineering ; Materials engineering (FZU-D) Impact factor: 0.436, year: 2016 https://www.researchgate.net/publication/313900224_Powder-metallurgy_preparation_of_NiTi_shape-memory_alloy_using_mechanical_alloying_and_spark-plasma_sintering

The Mechanical Metallurgy of Armour Steels

Science.gov (United States)

2016-10-01

plate hardness in Figure 2(a) are a result of increased resistance to plastic flow in a ductile hole formation failure mechanism. Beyond a certain...their mechanical metallurgy, and ballistic performance is explained, where such performance is primarily determined by material strength, hardness and...high strain rate behaviour. Other important topics such as toughness; the adiabatic shear phenomenon; structural cracking; and dual hardness and

NSF: A "Populist" Pattern in Metallurgy, Materials Research?

Science.gov (United States)

Shapley, Deborah

1975-01-01

Describes the testimony of a University of Virginia professor of applied science, who charged that the National Science Foundation grants disproportionately small funds to the best university departments in the field of metallurgy and materials, while preferentially funding middle-ranked departments. (MLH)

78 FR 8202 - Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy...

Science.gov (United States)

2013-02-05

... NUCLEAR REGULATORY COMMISSION Advisory Committee on Reactor Safeguards (ACRS) Meeting of the Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and Reactor Fuels; Notice of Meeting The Joint ACRS Subcommittees on Thermal Hydraulic Phenomena and Materials, Metallurgy and...

21. Colloquium on metallurgy. Amorphous alloys and materials

International Nuclear Information System (INIS)

1979-01-01

Twenty-two papers were presented at the 21st colloquium on metallurgy of amorphous alloys and materials. They deal with the applications, the various types, the preparation methods, the structure, the magnetic and thermodynamic properties and the structure defects of the amorphous materials [fr

One step HIP canning of powder metallurgy composites

Science.gov (United States)

Juhas, John J. (Inventor)

1990-01-01

A single step is relied on in the canning process for hot isostatic pressing (HIP) powder metallurgy composites. The binders are totally removed while the HIP can of compatible refractory metal is sealed at high vacuum and temperature. This eliminates outgassing during hot isostatic pressing.

Powder Metallurgy characteristics and application: state of the art

International Nuclear Information System (INIS)

Zaid, A.I.O.

2005-01-01

Powder metallurgy process (P/M) is a near-net or net-shape manufacturing process that combines the features of shape making technology of powder compaction with the development of final material and design properties (physical and mechanical) during subsequent densification or consolidation processes, e.g. sintering. It utilizes the metal powder or powders of metal alloys. In this paper, the major historical developments in P/M are reviewed and discussed. The main parameters involved in the process and their effects on the product characteristics are presented and discussed, which include: powders and methods of their production, particle size and shape, compressibility and additives, sintering temperature and time and finishing processes. The advantages and limitations of powder metallurgy are also presented and discussed. Finally, applications and future developments of the process are outlined and discussed. (author)

Fabrication by powder metallurgy of the niobium based alloy Nb-1-Zr

International Nuclear Information System (INIS)

Marty, M.; Delaunay, C.; Walder, A.

1989-01-01

The Nb-1Zr alloy has been produced by the powder metallurgy technique. Production of powders was performed by centrifugal atomization with the rotating electrode process (REP) under an inert atmosphere of argon-helium. Alloy powders were characterized by granulometric spectra, oxygen content and the various types of structures which were found. After consolidation by extrusion, materials were evaluated by tensile test under vacuum at ambient temperature, 750 and 900 0 C and compared with the same alloy elaborated by ingot metallurgy. 8 refs., 9 figs. (Author)

Welding of a powder metallurgy uranium alloy

International Nuclear Information System (INIS)

Holbert, R.K.; Doughty, M.W.; Alexander-Morrison, G.M.

1989-01-01

The interest at the Oak Ridge Y-12 Plant in powder metallurgy (P/M) uranium parts is due to the potential cost savings in the fabrication of the material, to achieving a more homogeneous product, and to the reduction of uranium scrap. The joining of P/M uranium-6 wt-% niobium (U-6Nb) alloys by the electron beam (EB) welding process results in weld porosity. Varying the EB welding parameters did not eliminate the porosity. Reducing the oxygen and nitrogen content in this P/M uranium material did minimize the weld porosity, but this step made the techniques of producing the material more difficult. Therefore, joining wrought and P/M U-6Nb rods with the inertia welding technique is considered. Since no gases will be evolved with the solid-state welding process and the weld area will be compacted, porosity should not be a problem in the inertia welding of uranium alloys. The welds that are evaluated are wrought-to-wrought, wrought-to-P/M, and P/M-to-P/M U-6Nb samples

Effect of Carbon Content on the Properties of Iron-Based Powder Metallurgical Parts Produced by the Surface Rolling Process

Directory of Open Access Journals (Sweden)

Yan Zhao

2018-01-01

Full Text Available In recent years, the rolling densification process has become increasingly widely used to strengthen powder metallurgy parts. The original composition of the rolled powder metallurgy blank has a significant effect on the rolling densification technology. The present work investigated the effects of different carbon contents (0 wt. %, 0.2 wt. %, 0.45 wt. %, and 0.8 wt. % on the rolling densification. The selection of the raw materials in the surface rolling densification process was analyzed based on the pore condition, structure, hardness, and friction performance of the materials. The results show that the 0.8 wt. % carbon content of the surface rolling material can effectively improve the properties of iron-based powder metallurgy parts. The samples with 0.8 wt. % carbon have the highest surface hardness (340 HV0.1 and the lowest surface friction coefficient (0.35. Even if the dense layer depth is 1.13 mm, which is thinner than other samples with low carbon content, it also meets the requirements for powder metallurgy parts such as gears used in the auto industry.

Scandium: its occurrence, chemistry, physics, metallurgy, biology, and technology

International Nuclear Information System (INIS)

Horovitz, C.T.

1975-01-01

This book describes the following aspects of scandium: discovery and history, occurrence in nature, geochemistry and mineralogy, chemical, physical and technological properties, fabrication and metallurgy, its biological significance and toxicology, and its uses. (Extensive references for each chapter)

Development of Cu-Be bronzes through powder metallurgy

International Nuclear Information System (INIS)

Abbas, M.

2012-01-01

Copper and copper alloys are the major group of commercial alloy. One of the important copper bronzes is Copper beryllium. This is unique among all engineering alloys. Copper beryllium alloy possesses the highest strength in all the copper base alloys. Development of copper beryllium alloy with powder metallurgy is challenging problem due to toxicity of beryllium dust. Purpose of this project to find out parameters by which copper beryllium with all unique properties should obtained. For this purpose efforts are put on development of alternative to copper beryllium system like copper-tin and copper-aluminum by powder metallurgy route. Different time of milling with uniaxial pressure of about 200 MPa and different sintering temperature according to phase diagram of alloy, with different soaking time is tried. Problems may occur like decrease in density after sintering, breaking of samples by Rockwell A, B and C indenters arid by hammering. Cold iso-static pressing at 300 MPa and sintering at above 900 degree C is used to develop copper beryllium alloy. As quenched samples are heat treated at 260 degree C, 315 degree C and 370 degree C with different soaking time of 30, 90 and 180 minutes to find out optimum time and temperature parameters. . It is observed that at aging at 260 degree C for 180 minutes, aging at 315 degree C for 180 minutes and aging at 370 degree C for 30 minutes produce optimum result. By observing these pellets by SEM, precipitates appeared in peak-aged alloy and bigger precipitates in over-aged alloy. Copper beryllium alloy developed through powder metallurgy has better prospects than other copper bronzes. (author)

Preparation of Three-Dimensional Graphene Foams Using Powder Metallurgy Templates.

Science.gov (United States)

Sha, Junwei; Gao, Caitian; Lee, Seoung-Ki; Li, Yilun; Zhao, Naiqin; Tour, James M

2016-01-26

A simple and scalable method which combines traditional powder metallurgy and chemical vapor deposition is developed for the synthesis of mesoporous free-standing 3D graphene foams. The powder metallurgy templates for 3D graphene foams (PMT-GFs) consist of particle-like carbon shells which are connected by multilayered graphene that shows high specific surface area (1080 m(2) g(-1)), good crystallization, good electrical conductivity (13.8 S cm(-1)), and a mechanically robust structure. The PMT-GFs did not break under direct flushing with DI water, and they were able to recover after being compressed. These properties indicate promising applications of PMT-GFs for fields requiring 3D carbon frameworks such as in energy-based electrodes and mechanical dampening.

Uranium 2000 : International symposium on the process metallurgy of uranium

International Nuclear Information System (INIS)

Ozberk, E.; Oliver, A.J.

2000-01-01

The International Symposium on the Process Metallurgy of Uranium has been organized as the thirtieth annual meeting of the Hydrometallurgy Section of the Metallurgical Society of the Canadian Institute of Mining, Metallurgy and Petroleum (CIM). This meeting is jointly organized with the Canadian Mineral Processors Division of CIM. The proceedings are a collection of papers from fifteen countries covering the latest research, development, industrial practices and regulatory issues in uranium processing, providing a concise description of the state of this industry. Topics include: uranium industry overview; current milling operations; in-situ uranium mines and processing plants; uranium recovery and further processing; uranium leaching; uranium operations effluent water treatment; tailings disposal, water treatment and decommissioning; mine decommissioning; and international regulations and decommissioning. (author)

Comprehensive waste characterization and organic pollution co-occurrence in a Hg and As mining and metallurgy brownfield.

Science.gov (United States)

Gallego, J R; Esquinas, N; Rodríguez-Valdés, E; Menéndez-Aguado, J M; Sierra, C

2015-12-30

The abandonment of Hg-As mining and metallurgy sites, together with long-term weathering, can dramatically degrade the environment. In this work it is exemplified the complex legacy of contamination that afflicts Hg-As brownfields through the detailed study of a paradigmatic site. Firstly, an in-depth study of the former industrial process was performed to identify sources of different types of waste. Subsequently, the composition and reactivity of As- and Hg-rich wastes (calcines, As-rich soot, stupp, and flue dust) was analyzed by means of multielemental analysis, mineralogical characterization (X-ray diffraction, electronic, and optical microscopy, microbrobe), chemical speciation, and sequential extractions. As-rich soot in the form of arsenolite, a relatively mobile by-product of the pyrometallurgical process, and stupp, a residue originated in the former condensing system, were determined to be the main risk at the site. In addition, the screening of organic pollution was also aimed, as shown by the outcome of benzo(a) pyrene and other PAHs, and by the identification of unexpected Hg organo-compounds (phenylmercury propionate). The approach followed unravels evidence from waste from the mining and metallurgy industry that may be present in other similar sites, and identifies unexpected contaminants overlooked by conventional analyses. Copyright © 2015 Elsevier B.V. All rights reserved.

Melting decontamination and recycling of radioactive polluted metals from uranium mining and metallurgy

International Nuclear Information System (INIS)

Chen Anquan

2011-01-01

Melting method is a primary method used for decontamination of radioactive polluted metal from uranium mining and metallurgy. The decontamination mechanism of the method, the way selection and its features are introduced. Taking the ten year's work of CNNC Uranium Mining and Metallurgy Radioactive Polluted Metal Melting Processing Center as example, the effects of processing radioactive polluted metals by smelting method are discussed. The surface pollution levels of radioactive polluted metal from uranium mining and metallurgy decreased from 4-48 Bq/cm 2 before decontamination to 0.004-0.016 Bq/cm 2 after decontamination, and the specific activity of its metal is less than 1 Bq/g, which is below the solution control level proposed by IAEARS-G1.7 'the application of the concepts of exclusion, immunity and solution control'. The metals after decontamination can be recycled by producing tooth plate and bucket teeth of excavator used in mines. (authors)

Building of effluence and environment monitoring capability of uranium mining and metallurgy in China

International Nuclear Information System (INIS)

Li Xianjie; Hu Penghua; Duan Jianchen; Xue Jianxin

2014-01-01

The status of effluence and environmental monitoring capability of nine uranium mining and metallurgy corporations in operation in China was investigated and analyzed. The results show that there exist some problems in all corporations such as imperfect monitoring plan, ineligible analyst, aging equipment, insufficient analysis capacity, lack of good detection limit. In order to solve the problems, several steps have been taken by Department of Safety and Environment Protection and Department of Geology and Mining (CNNC) in three years, including establishing three-level monitoring sys- tem, equipping corresponding monitoring instrument, holding three training classes, enhancing the analyst capacity, publishing the model for effluence and environment monitoring capability of uranium mining and metallurgy and carrying out comparison on monitoring of U and Ra in water, which greatly improved effluence and environment monitoring capability of uranium mining and metallurgy. (authors)

[Hygienic evaluation of risk factors on powder metallurgy production].

Science.gov (United States)

2011-01-01

Complex hygienic, clinical, sociologic and epidemiologic studies revealed reliable relationship between work conditions and arterial hypertension, locomotory system disorders, monocytosis in powder metallurgy production workers. Findings are more probable cardiovascular and respiratory diseases, digestive tract diseases due to influence of lifestyle factors.

Analysis of characteristics and radiation safety situation of uranium mining and metallurgy facilities in north area of China

International Nuclear Information System (INIS)

Liu Ruilan; Li Jianhui; Wang Xiaoqing; Huang Mingquan

2014-01-01

According to the radiation safety management of uranium mining and metallurgy facilities in north area of China, features and radiation safety conditions of uranium mining and metallurgy facilities in north area of China were analyzed based on summarizing the inspection data for 2011-2013. So the main problems of radiation environment security on uranium mine were studied. The relevant management measures and recommendations were put forward, and the basis for environmental radiation safety management decision making of uranium mining and metallurgy facilities in future was provided. (authors)

The economic analysis of the evolution of Romanian ferrous metallurgy

Directory of Open Access Journals (Sweden)

I. Bostan

2012-10-01

Full Text Available The ferrous metallurgy represents a traditional occupation, being extremely important for the national economy. Romania has gone through all the stages foreseen for the restructuring of this industry in compliance with the provisions of the European Council’s Decision (1999/582/EC concerning the partnership for the EU adherence, which included a special chapter on ferrous metallurgy, the provisions of the Protocol no. 2 (ECSC, as well as with other significant normative acts subsequently enacted. Following the performed restructuring – privatizations, state allowances, liquidations, re-technologization – the activity of this sector has developed, still being under the potential of the Romanian metallurgic industry. Nowadays, the disadvantages relating to energy intensity and the increased need for imported raw materials are doubled by the difficulties generated by the global crisis.

Advances in Powder Metallurgy Soft Magnetic Composite Materials

Directory of Open Access Journals (Sweden)

Bureš R.

2017-06-01

Full Text Available Powder metallurgy has grown with the expansion of various industry. Automotive industry had the most strong influence. Today, more than 90% of PM products are used in the transportation industry. Development of new materials such as magnetic materials is expected to meet the new trends of automotive industry, electric and hybrid vehicles.

Review of the physical metallurgy of Alloy 718

International Nuclear Information System (INIS)

Keiser, D.D.; Brown, H.L.

1976-02-01

The physical metallurgy of Alloy 718 is updated to 1976 on the basis of a survey of post-1967 literature and current experimental data. Composition, microstructures, and mechanical properties are correlated with heat treatment parameters. The current state of understanding of phase stability, strengthening mechanisms, deformation modes, recovery, and recrystallization in this material is described

N18, powder metallurgy superalloy for disks: Development and applications

Energy Technology Data Exchange (ETDEWEB)

Guedou, J.Y.; Lautridou, J.C.; Honnorat, Y. (SNECMA, Evry (France). Materials and Processes Dept.)

1993-08-01

The preliminary industrial development of a powder metallurgy (PM) superalloy, designated N18, for disk applications has been completed. This alloy exhibits good overall mechanical properties after appropriate processing of the material. These properties have been measured on both isothermally forged and extruded billets, as well as on specimens cut from actual parts. The temperature capability of the alloy is about 700 C for long-term applications and approximately 750 C for short-term use because of microstructural instability. Further improvements in creep and crack propagation properties, without significant reduction in tensile strength, are possible through appropriate thermomechanical processing, which results in a large controlled grain size. Spin pit tests on subscale disks have confirmed that the N18 alloy has a higher resistance than PM Astrology and is therefore an excellent alloy for modern turbine disk applications.

Physical metallurgy and physics of solids

International Nuclear Information System (INIS)

Friedel, J.

1997-01-01

A historical review of the development of fundamental research at the Cea in the field of material science, is presented, beginning with the study of material issues for nuclear applications, such as the growth, the swelling (of uranium and its alloys) and the embrittlement of steels. Other researches led to the introduction of plutonium in uranium oxide, paving the way to MOX fuels, and the study of diffusion in fundamental metallurgy, hot plasticity especially the hexagonal metals) and steady state conditions under irradiation

A review of experiment data processing method for uranium mining and metallurgy in BRICEM

International Nuclear Information System (INIS)

Ye Guoqiang; Lu Kehong; Wang Congying

1997-01-01

The authors investigates the methods of experiment data processing in Beijing Research Institute of Chemical Engineering and Metallurgy (BRICEM). It turns out that error analysis method is used to process experiment data, single-factor transformation and orthogonal test design method are adopted for arranging test, and regression analysis and mathematical process simulation are applied to process mathematical model for uranium mining and metallurgy. The methods above-mentioned lay a foundation for the utilization of mathematical statistics in our subject

Studies on ancient silver metallurgy using SR XRF and micro-PIXE

Science.gov (United States)

Vasilescu, Angela; Constantinescu, Bogdan; Stan, Daniela; Radtke, Martin; Reinholz, Uwe; Buzanich, Guenter; Ceccato, Daniele

2015-12-01

This work presents a complex evaluation of a series of Geto-Thracian silver adornments found on Romanian territory, part of the 4th century BC Agighiol (Northern Dobruja) hoard and of an ingot from the 1st century BC Geto-Dacian Surcea (Transylvania) hoard, using Synchrotron Radiation X-Ray Fluorescence and micro- Proton Induced X-ray Emission analysis and mapping in order to investigate aspects related to the elemental composition of the metal and the metallurgy implied in their manufacture. One of the samples can be linked to Laurion as the source of metal, and several items contain silver probably originated in Macedonia. The set of silver items was found to be heteregenous as composition and microstructure, and corrosion-related elements could be also identified in the X-Ray maps.

Making Self-Lubricating Parts By Powder Metallurgy

Science.gov (United States)

Sliney, Harold E.; Dellacorte, Christopher

1990-01-01

Compositions and parameters of powder-metallurgical fabrication processes determined for new class of low-friction, low-wear, self-lubricating materials. Used in oxidizing or reducing atmospheres in bearings and seals, at temperatures from below 25 degrees C to as high as 900 degrees C. Thick parts made with minimal waste.

Application of Microscopy and X-ray Diffraction in Optimization of the Production of NiTi Alloy by Powder Metallurgy

Czech Academy of Sciences Publication Activity Database

Novák, P.; Školáková, A.; Vojtěch, V.; Knaislová, A.; Pokorný, P.; Moravec, H.; Kopeček, Jaromír; Karlík, M.; Kubatík, Tomáš František

2014-01-01

Roč. 14, č. 3 (2014), s. 387-392 ISSN 1213-2489. [Mezinárodní konference „Mikroskopie a nedestruktivní zkoušení materiálů/3./. Litoměřice, 22.10.2014-24.10.2014] R&D Projects: GA ČR(CZ) GA14-03044S Institutional support: RVO:61389021 ; RVO:68378271 Keywords : powder metallurgy * NiTi, * mechanical alloying * reactive sintering Subject RIV: JG - Metallurgy; JG - Metallurgy (FZU-D) http://journal.strojirenskatechnologie.cz/templates/obalky_casopis/XIV_2014-3.pdf

Peculiarities of powder metallurgy of vanadium and its alloys

International Nuclear Information System (INIS)

Radomysel'skij, I.D.; Solntsev, V.P.; Evtushenko, O.V.

1987-01-01

Literature data on preparation of vanadium powder and powder materials on the vanadium base are generalized. Application of powder metallurgy engineering, allowing simulaneously to introduce practically any strengthening and solid-lubricating components as well as to alloy vanadium, permits undoubtedly to develop composite materials on the vanadium base

Non destructive testing of green parts in powder metallurgy

International Nuclear Information System (INIS)

Accary, A.

1979-01-01

The non destructive testing of green parts is potentially advantageous by making possible a lowering of the material and energy consumption as well as the production of parts with a 100% reliability. After a survey of the possible methods and of the defects to be detected it is shown that the goal can be achieved using a 'blind detection' method and that the difficulty of the problem depends on the size and shape of the part to be controled. The gravimetric, dimensional, γ absorption and thermal diffusivity methods are then examined. It is concluded that a unit control is paying only if it allows to enter the high reliability part market. Used statisticaly the non destructive testing of green parts can possibly lead to savings on materials and energy [fr

Mechanical properties of AZ31 alloy processed by a green metallurgy route; Propiedades mecanicas de la aleacion AZ31 procesada por una ruta eco-sostenible

Energy Technology Data Exchange (ETDEWEB)

D' Enrico, F.; Garces, G.; Hofer, M.; Kim, S. K.; Perez, P.; Cabeza, S.; Adeva, P.

2013-07-01

Recently it has been proved that molding of defect-free components of various commercial alloys of magnesium can be carried out successfully when small amounts of CaO are added to the melt, making unnecessary the use of SF{sub 6} coverage. In the case of AZ alloys, this process also remarkably improves their mechanical properties not only by the greater cleaning of alloys but also by the formation of CaAl{sub 2} phase. This work, part of the Green project Metallurgy (http://www.green-metallurgy.eu) funded by the European Union (LIFE+2009), studies the influence of different CaO additions on the microstructure and mechanical properties of AZ31 Eco-Mg alloy. The alloy was processed by a conventional route involving extrusion of as-cast rods as well as by a powder metallurgy route (PM) using chips as starting material. The objective was to analyze the viability of recycling machining chips to manufacture components for the automobile industry and transportation in general, because of its low cost and environmental impact. It has been demonstrated that alloys processed from chips exhibit the highest tensile stress values, close to 320 MPa. (Author)

Metallurgy Department annual progress report for 1987

International Nuclear Information System (INIS)

Schroeder Pedersen, A.; Bilde-Soerensen, J.B.; Hansen, N.

1988-05-01

Selected activities of the Metallurgy Department at Risoe National Laboratory during 1987 are described. The work is presented in four chapters: Materials Science, Materials Engineering, Materials Technology and Energy Programmes. A survey is given of the Department's participation in international collaboration and of its activities within education and training. Furthermore, the main numbers illustrating the Departments's economy are given. Lists of staff members, visiting scientists, publications, lectures and poster presentations are included. 38 ills. (author)

Proceedings of the 1985 annual powder metallurgy conference

International Nuclear Information System (INIS)

Sanderow, H.I.; Giebelhausen, W.L.; Kulkarni, K.M.

1985-01-01

This book presents the papers given at a conference on powder metallurgy. Topics considered at the conference included yttrium oxide dispersion strengthened nickel alloy made by mechanical alloying, the optimal design of regression of the additive chromium oxide in aluminium oxide-molybdenum cermets, particle size distribution effects on the sintering of spherical tungsten, and heavy metal alloys containing 30% to 90% tungsten

Metallurgy and purification of semiconductor materials

International Nuclear Information System (INIS)

Mughal, G.R.; Ali, M.M.; Ali, I.

1996-01-01

In this article the metallurgical aspects of semiconductor science and technology have been stressed here rather than of the physical and electronic aspect of the subject. Semiconductor technology has not merely presented the metallurgist with new challenges. The ease with which the semiconductor planes cleave make possible, the preparation and study of virgin surface. Semiconductor materials were being widely employed in the study of sub-boundaries and structures and can largely contribute to the study of certain aspects of nucleation and growth, precipitation phenomena, mechanical behaviour, in metallurgy. (A.B.)

Iron Metallurgy: Technical Terminology Bulletin. Terminotech, Vol. 2, No. 7.

Science.gov (United States)

General Electric Co. of Canada, Ltd., Montreal, Quebec.

This issue of a bulletin of technological terminology is devoted to iron metallurgy. Various aspects of iron production are described in both French and English. An English-French dictionary of terms comprises the bulk of the document. Explanatory illustrations are appended. (JB)

Quantifying the properties of low-cost powder metallurgy titanium alloys

International Nuclear Information System (INIS)

Bolzoni, L.; Ruiz-Navas, E.M.; Gordo, E.

2017-01-01

The extensive industrial employment of titanium is hindered by its high production costs where reduction of these costs can be achieved using cheap alloying elements and appropriate alternative processing techniques. In this work the feasibility of the production of low-cost titanium alloys is addressed by adding steel to pure titanium and processing the alloys by powder metallurgy. In particular, a spherical 4140 LCH steel powder commonly used in metal injection moulding is blended with irregular hydride-dehydride Ti. The new low-cost alloys are cold uniaxially pressed and sintered under high vacuum and show comparable properties to other wrought-equivalent and powder metallurgy titanium alloys. Differential thermal analysis and X-ray diffraction analyses confirm that Ti can tolerate the employment of iron as primary alloying element without forming detrimental TiFe-based intermetallic phases. Thus, the newly designed α+β alloys could be used for cheaper non-critical components.

Quantifying the properties of low-cost powder metallurgy titanium alloys

Energy Technology Data Exchange (ETDEWEB)

Bolzoni, L., E-mail: bolzoni.leandro@gmail.com [WaiCAM (Waikato Centre for Advanced Materials), The University of Waikato, Private Bag 3105, 3240 Hamilton (New Zealand); Ruiz-Navas, E.M.; Gordo, E. [Department of Materials Science and Engineering, University Carlos III of Madrid, Avda. de la Universidad, 30, 28911 Leganés, Madrid (Spain)

2017-02-27

The extensive industrial employment of titanium is hindered by its high production costs where reduction of these costs can be achieved using cheap alloying elements and appropriate alternative processing techniques. In this work the feasibility of the production of low-cost titanium alloys is addressed by adding steel to pure titanium and processing the alloys by powder metallurgy. In particular, a spherical 4140 LCH steel powder commonly used in metal injection moulding is blended with irregular hydride-dehydride Ti. The new low-cost alloys are cold uniaxially pressed and sintered under high vacuum and show comparable properties to other wrought-equivalent and powder metallurgy titanium alloys. Differential thermal analysis and X-ray diffraction analyses confirm that Ti can tolerate the employment of iron as primary alloying element without forming detrimental TiFe-based intermetallic phases. Thus, the newly designed α+β alloys could be used for cheaper non-critical components.

Preparation of magnesium metal matrix composites by powder metallurgy process

Science.gov (United States)

Satish, J.; Satish, K. G., Dr.

2018-02-01

Magnesium is the lightest metal used as the source for constructional alloys. Today Magnesium based metal matrix composites are widely used in aerospace, structural, oceanic and automobile applications for its light weight, low density(two thirds that of aluminium), good high temperature mechanical properties and good to excellent corrosion resistance. The reason of designing metal matrix composite is to put in the attractive attributes of metals and ceramics to the base metal. In this study magnesium metal matrix hybrid composite are developed by reinforcing pure magnesium with silicon carbide (SiC) and aluminium oxide by method of powder metallurgy. This method is less expensive and very efficient. The Hardness test was performed on the specimens prepared by powder metallurgy method. The results revealed that the micro hardness of composites was increased with the addition of silicon carbide and alumina particles in magnesium metal matrix composites.

Metallurgy Department. Annual progress report for 1988

International Nuclear Information System (INIS)

Schroeder Pedersen, A.; Bilde-Soerensen, J.B.; Hansen, N.

1989-05-01

Selected activities of the Metallurgy Department at Risoe National Laboratory during 1988 are described. The work is presented in four chapters: Materials Science, Materials Engineering, Materials Technology and Energy Programmes. A survey is given of the Department's participation in international collaboration and of its activities within education and training. Furthermore, the main numbers illustrating the Department's economy are given. Lists of staff members, visiting scientists, publications, lectures and poster presentations are included. (author) 36 ills., 81 refs

Metallurgy Department. Annual progress report for 1989

International Nuclear Information System (INIS)

Horsewell, A.; Hansen, N.

1990-07-01

Selected activities of the Metallurgy Department at Risoe National Laboratory during 1989 are described. The work is presented in three chapters: Materials Science, Materials Engineering and Materials Technology. A survey is given of the Department's participation in international collaboration and of its acitivities within eduation and training. Furthermore, the main figures outlining the funding and expenditure of the Department are given. Lists of staff members, visiting scientists, publicaltions, lectures and poster presentations are included. (author) 90 refs

Properties of WZ21 (%wt) alloy processed by a powder metallurgy route.

Science.gov (United States)

Cabeza, Sandra; Garcés, Gerardo; Pérez, Pablo; Adeva, Paloma

2015-06-01

Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 μm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prerequisites and opportunities for repositioning of the Urals metallurgy within the Industry 4.0

Directory of Open Access Journals (Sweden)

O. A. Romanova

2017-12-01

Full Text Available The authors present the modern trends in the development of metallurgy, and classify the technological structure of metallurgical industry. The article contains specific features of the development of metallurgy in the conditions of industry formation. A special role in this process plays the pace of digitalization and robotization of the industry, the development of additive technologies, Internet of things. The authors substantiate the possibility of developing the metallurgy of the Middle Urals as a science-intensive, high-tech complex that meets the requirements of Industry 4.0. This possibility interrelates with its repositioning, one of the main tasks of which is the formation of new sales markets focused on high-tech consumer industries, as well as the preservation of traditional consumption sectors under conditions of increasing competition in the construction materials market. The authors underline the importance of international cooperation in the field of environmentally safe industrial development, with applying the best available technologies and innovative development in general. The authors propose a methodological approach for assessing the repositioning of the regional metallurgical complex. This approach is the consecutive implementation of the following stages: assessment of dynamics and the forecast of development of consumer steel products sector and its structure based on identified priority areas of technological development of metallurgy in the region; construction of a factor model describing the changes in parameters of the RMC repositioning process, and approximation of the characteristics of their nonlinear elements; building a mathematical model on the basis of neural network algorithms for assessing the process of repositioning the RMC, taking into account projected values of the RMK parameters in the process of repositioning and changing the structure of consumer markets for metal products; formation of a variable

The most essential tendencies in development of powder metallurgy

International Nuclear Information System (INIS)

Fedorchenko, I.M.

1989-01-01

A progress in the sphere of creation and application of new types of powder materials is characterized. The materials are as follows: structural, tribotechnical, composite, reinforced, precipitation-hardened, refractory, tool, materials based on light metals and others. A number of important problems whose solution will promote a further development of powder metallurgy are formulated

Evaluation of powder metallurgy superalloy disk materials

Science.gov (United States)

Evans, D. J.

1975-01-01

A program was conducted to develop nickel-base superalloy disk material using prealloyed powder metallurgy techniques. The program included fabrication of test specimens and subscale turbine disks from four different prealloyed powders (NASA-TRW-VIA, AF2-1DA, Mar-M-432 and MERL 80). Based on evaluation of these specimens and disks, two alloys (AF2-1DA and Mar-M-432) were selected for scale-up evaluation. Using fabricating experience gained in the subscale turbine disk effort, test specimens and full scale turbine disks were formed from the selected alloys. These specimens and disks were then subjected to a rigorous test program to evaluate their physical properties and determine their suitability for use in advanced performance turbine engines. A major objective of the program was to develop processes which would yield alloy properties that would be repeatable in producing jet engine disks from the same powder metallurgy alloys. The feasibility of manufacturing full scale gas turbine engine disks by thermomechanical processing of pre-alloyed metal powders was demonstrated. AF2-1DA was shown to possess tensile and creep-rupture properties in excess of those of Astroloy, one of the highest temperature capability disk alloys now in production. It was determined that metallographic evaluation after post-HIP elevated temperature exposure should be used to verify the effectiveness of consolidation of hot isostatically pressed billets.

Innovative solutions for the extraction of technology metals from complex primary and secondary raw materials

Directory of Open Access Journals (Sweden)

Kamberović Željko J.

2016-01-01

Full Text Available Presented compilation of scientific, theoretical and experimental results, promotes an innovative synergy of various metals and industrial activities in metallurgy, resulting in profitable transformation of by­products and waste materials into resources. Focusing on treatment of specific by-products from zinc and copper primary production, as well on specific waste streams like WEEE and waste automotive catalysts, group is actively contribute to the Serbia, region and EU sustainability policies. In terms of sustainable development, metallurgy is a traditional part of the solution rather than part of the problem, so it is necessary to take the chance and centuries-old tradition.

The metallurgy of alloy 800

International Nuclear Information System (INIS)

Stone, P.G.; Orr, J.; Guest, J.C.

1975-01-01

Following a review of published information on the metallurgy of the iron/chromium/nickel system, attention is directed to the metallurgical significance of relatively minor compositional variations introduced in Alloy 800 to meet the stress corrosion requirements of the nuclear power industry. These include the effect of carbon, nitrogen, titanium, and aluminium restrictions in the context of Light Water Reactor, High Temperature Reactor, and Fast Reactor applications. Solubility effects are also considered in relation to heat treatment procedures, metallurgical phenomena, and associated properties. The aging behaviour is also discussed and related to fabrication and service performance; particularly stress rupture behaviour. The effect of strain at ambient and elevated temperatures on these aspects is indicated. (author)

Chemical and Metallurgy Research (CMR) Sample Tracking System Design Document

International Nuclear Information System (INIS)

Bargelski, C. J.; Berrett, D. E.

1998-01-01

The purpose of this document is to describe the system architecture of the Chemical and Metallurgy Research (CMR) Sample Tracking System at Los Alamos National Laboratory. During the course of the document observations are made concerning the objectives, constraints and limitations, technical approaches, and the technical deliverables

Influence of thermo-mechanical processing on the microstructure of Cu-based shape memory alloys produced by powder metallurgy

International Nuclear Information System (INIS)

Rodriguez, P.P.; Ibarra, A.; Iza-Mendia, A.; Recarte, V.; Perez-Landazabal, J.I.; San Juan, J.; No, M.L.

2003-01-01

Cu-Al-Ni shape memory alloys processed by powder metallurgy show very good thermo-mechanical properties, much better than those found in alloys produced by conventional casting. In this paper, we present the microstructural characterisation of these powder metallurgy alloys in order to find the microscopic mechanisms, linked to the powder metallurgy processing method, which are indeed responsible of such good thermo-mechanical behaviour. Electron microscopy studies [scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM)] show that powder metallurgy processing creates a sub-grain structure characterised by the presence of low angle sub-boundaries. These sub-boundaries are found to be lying on {1 1 0} and {1 1 2} lattice planes and are composed by an arrangement of superdislocations. These sub-boundaries may improve ductility in two ways: acting as a sink of dislocations which promotes plastic deformation and decreasing stress concentration at grain boundaries. Moreover, since sub-boundaries act as weak obstacles for the movement of martensite plates, the improvement on ductility is accomplished by an adequate thermo-mechanical behaviour

The decision to extract: Part 1--Interclinician agreement.

Science.gov (United States)

Baumrind, S; Korn, E L; Boyd, R L; Maxwell, R

1996-03-01

As part of an ongoing prospective clinical trial of conventional orthodontic treatment, the decision making patterns of a representative group of orthodontic clinicians were examined. Data were available for 148 subjects (100 adolescents and 48 adults) who had presented at the University of California San Francisco Graduate Orthodontic Clinic requesting treatment for correction of a Class I or Class II malocclusion. The records for each subject were evaluated independently by each of five members of the clinical faculty, making available a total of 740 independent patient evaluations. With regard to the primary decision as to whether extraction or nonextraction treatment was to be preferred, agreement among clinicians was higher than had been anticipated. In almost two thirds of the cases, the decisions of all five clinicians were in agreement as to whether extraction or nonextraction was the preferred treatment modality. (This figure included 59 cases of complete agreement for extraction therapy (40%) and 38 cases of complete agreement for nonextraction therapy (26%)). In only 51 cases (34%), did the reviewing clinicians disagree as to whether extraction or nonextraction was the preferred modality of treatment. The clinicians were also asked to indicate their opinions as to whether orthognathic surgery was likely to be a part of the ultimate treatment course for each individual subject. Nine percent of the 740 patient evaluations contained a clinician judgement that surgery would be a probable or definite component of the orthodontic treatment plan. For 29% of the adult subjects (14 cases) and 23% of the adolescent subjects (23 cases), one or more of the five examining clinicians believed that adjunctive surgical intervention would probably or definitely be appropriate. These high values were unexpected, particularly because the sample had been prescreened by a single clinician to exclude subjects who might require orthognathic surgery. Clinician agreement of

Contribution to the study of copper and copper-arsenic archaeo-metallurgy using light element analysis and experimental fusion

International Nuclear Information System (INIS)

Papillon, F.

1997-01-01

The objective of this study is to try a direct reconstruction from ancient artefacts of the elaboration technology used in the dawning copper metallurgy. This word is based on both the light elements analysis and the carry out of the principles of physical metallurgy. However the study of an archaeological artefact necessitates the use of non destructive methods. A main aspect of this work consists in developing the most adequate metallographic technique and the methods for the determination of oxygen and carbon by ion beam analysis. Additionally experimental melting of copper and copper arsenic alloys were carried out in laboratory, under various temperature and atmosphere conditions, and 'on the field' in Archeodrome de Beaune, in order to reconstruct part of the prehistorical craftsmanship. The results of measurement are consistent with our general knowledge of oxido-reduction phenomena and the behaviour of copper and copper arsenic alloys s in agreement with the prediction of thermodynamics. The nuclear analysis of three ancient artefacts showed that the oxygen and carbon contents were closer to those of the Archeodrome than those of the laboratory. Further studies of the field should consider all parameters controlling the physical-chemistry of charcoal fire. (author)

Production of uranium in Navoi Mining and Metallurgy Combinat, Uzbekistan

International Nuclear Information System (INIS)

Kuchersky, N.; Tolstov, E.A.; Mazurkevich, A.P.; Inozemzev, S.B.

2001-01-01

the mining sites and processing facilities. During these periods, three principle flowsheets were tested and introduced at the ISL sites of the Navoi Mining and Metallurgy Combinat: sulfuric acid scheme, acid and bicarbonate scheme, weak acid scheme. Out of these three, the sulfuric acid and weak acid schemes have been more intensively developed. The commercial scale operation of the new method of leaching, using as a leach the ore body water saturated with air, and practically free of reagents, resulted in the reduction of the mining cost and laid the foundation for environmentally friendly operational method. Optimal parameters of the ISL process have been established including method of processing the pregnant solutions by sorption and the arrangement of the appropriate equipment; methods of well construction which is efficient for any particular conditions and ways to restore their productivity during the course of exploitation, a new production well grid arrangements in connection with hydrological and geological conditions of horizons under development, and an effective lifting equipment for pregnant solutions; methods for extraction of rhenium from ISL solutions as a by-product; and the recovery of scandium oxides from wastes after the hydrometallurgical treatment of the ISL solutions. Under the transition to market-oriented economy the major effort of the Combinat is focused on reducing the cost of uranium production by the implementation of an up-to-date innovations in ISL technology. We are in the process of re-equipping our drilling facilities by replacing out-of-date and depreciated major equipment. A new plant has been commissioned for the production of PVC casing pipes necessary for the completion of production wells thus covering the requirements of the entire ISL complex for the near future and for many years to come. Based on modern control and measurement instrumentation we introduce automated control systems for ISL process with broad communication

Evaluation of Antioxidant Activity from Different Plant Parts of Senduduk Herb: Extraction Conditions Optimization of Selected Plant Part

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Kamaludin Nor Helya Iman

2017-01-01

Full Text Available This work reports a study on evaluation of antioxidant properties from flower of Senduduk herb. Natural occurring antioxidant was mostly preferred due to their little or no toxicity compared to the synthetic antioxidants which posses carcinogenic effects. Extraction was done on selected plant parts of Sendududk herb including leaves, stem, flower and berry parts to evaluate their antioxidant potentiality. Flower part of Sendudk herb extracted using acetonic solvent promotes highest antioxidant activity which is 93.97 ± 1.38 % as compared to leaves (92.20 ± 0.20 %, stem (47.94 ± 1.42% and berry (92.88 ± 0.63% using the same extracting solvent. Thus, Senduduk flower was chosen to be continued with screening and optimization process. Single factor experiment using the one factor at a time (OFAT method was done to study the effect of each extraction parameter that was solid to solvent ratio, temperature and solvent concentration. The extraction condition in each parametric study which results in highest antioxidant activity was used as the middle level of optimization process using Response Surface Methodology (RSM coupled with Central Composite Design (CCD. The optimum condition was at 1:20 solid to solvent ratio, 64.61°C temperature and 80.24% acetone concentration which result in antioxidant activity of 96.53%. The verification of RSM showed that the model used to predict the antioxidant activity was valid and adequate with the experimental parameters.

Borax as a lubricant in powder metallurgy

Directory of Open Access Journals (Sweden)

Héctor Geovanny Ariza-Suarez

2014-12-01

were compacted at 700 MPa in a uniaxial press of 15 tons. DSC-TGA analysis of the mixture with borax was realized. The specimens were sintered in a plasma reactor at 1000 for 30 minutes, with a combined atmosphere of hydrogen and argon. Microhardness and density of the sintered samples was haracterized. XRD analysis was realized to detect possible compounds formation by interaction of borax. This paper shows that borax can be used as a lubricant in powder metallurgy.

Modernization of the Ural Metallurgy during the Great Patriotic War (1941–1945

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Vladimir V. Zaparii

2013-09-01

Full Text Available The article characterizes the Ural industry modernization in war footing, shows the significance of evacuation of enterprises from the Western areas of the country to the region, reveals their role in the formation of a new metallurgical center of modern metallurgy in terms of human resources and manufacture. Innovations in metallurgy, the role of human factor in solving industrial restructuring problem are examined. Forms and methods of science use for the industrial modernization are considered. Solving of human resources problem is shown. The author touches upon the problem of metallurgical sector management in wartime. The role of people’s heroism in this difficult period of Russian history is discussed.

Thermal stability and creep behaviour of MgNiYCe-rich mischmetal alloys processed by a powder metallurgy route

Czech Academy of Sciences Publication Activity Database

Peréz, P.; Milička, Karel; Badia, J. M.; Garcés, G.; Antoranz, J. M.; Gonzáles, S.; Dobeš, Ferdinand; Adeva, P.

289-292, - (2009), s. 127-136 ISSN 1012-0386. [DIMAT 2008, International Conference on Diffusion in Materials /7./. Lanzarote, Canary Islands, 28.10.2008-31.10.2008] Grant - others:Ministerio de Ciencia y Tecnologia (ES) MAT2006-11731-C02 Institutional research plan: CEZ:AV0Z20410507 Keywords : magnesium alloys * powder metallurgy * microstructure * thermal stability * creep Subject RIV: JG - Metallurgy

Indexation Rules for Metallurgy in PASCAL. Original Title: Regles d'Indexation de la Metallurgie'--Technical Note Issued by Informascience--January 1980. Translated by Marie Wallin.

Science.gov (United States)

Royal Inst. of Tech., Stockholm (Sweden). Library.

The indexing rules presented are designed for use with a new French-German database on metallurgy being developed under an agreement by CNRS (Centre National de la Recherche Scientifique, Paris) and BAM (Bundesanstalt fur Materialprufung, Berlin). The new database, which will feature multilingual titles and index terms (French-German-English-) and…

Powder Metallurgy Preparation of Co-Based Alloys for Biomedical Applications

Czech Academy of Sciences Publication Activity Database

Marek, I.; Novák, P.; Mlynár, J.; Vojtěch, D.; Kubatík, Tomáš František; Málek, J.

2015-01-01

Roč. 128, č. 4 (2015), s. 597-601 ISSN 0587-4246. [International Symposium on Physics of Materials (ISPMA) /13./. Prague, 31.08.2014-04.09.2014] Institutional support: RVO:61389021 Keywords : powder metallurgy * mechanical properties * biomedical applications Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 0.525, year: 2015

The mysterious world of plutonium metallurgy: Past and future

International Nuclear Information System (INIS)

Hecker, S.S.; Hammel, E.F.

1998-01-01

The first atomic bomb detonated at the Trinity Site in New Mexico on July 16, 1945, used plutonium, a man-made element discovered < 5 yr earlier. The story of how Manhattan Project scientists and engineers tackled the mysteries of this element and fabricated it into the first atomic bomb is one of the most fascinating in the history of metallurgy and materials. The authors are currently trying to generate renewed interest in plutonium metallurgy because of the challenge posed by President Clinton, i.e., to keep the nuclear stockpile of weapons safe and reliable without nuclear testing. The stockpile stewardship challenge requires either a lifetime extension of the plutonium components or a remanufacture--neither of which can be verified by testing. In turn, this requires that one achieve a better fundamental understanding of plutonium. Of special interest is the effect of self-irradiation on the properties and on the long-term stability of plutonium and its alloys. Additional challenges arise from long-term concerns about disposing of plutonium and dealing with its environmental legacy. It is imperative to interest the next generation of students in these plutonium challenges

State-of-the-art of recycling e-wastes by vacuum metallurgy separation.

Science.gov (United States)

Zhan, Lu; Xu, Zhenming

2014-12-16

In recent era, more and more electric and electronic equipment wastes (e-wastes) are generated that contain both toxic and valuable materials in them. Most studies focus on the extraction of valuable metals like Au, Ag from e-wastes. However, the recycling of metals such as Pb, Cd, Zn, and organics has not attracted enough attentions. Vacuum metallurgy separation (VMS) processes can reduce pollution significantly using vacuum technique. It can effectively recycle heavy metals and organics from e-wastes in an environmentally friendly way, which is beneficial for both preventing the heavy metal contaminations and the sustainable development of resources. VMS can be classified into several methods, such as vacuum evaporation, vacuum carbon reduction and vacuum pyrolysis. This paper respectively reviews the state-of-art of these methods applied to recycling heavy metals and organics from several kinds of e-wastes. The method principle, equipment used, separating process, optimized operating parameters and recycling mechanism of each case are illustrated in details. The perspectives on the further development of e-wastes recycling by VMS are also presented.

Powder-metallurgy superalloy strengthened by a secondary gamma phase.

Science.gov (United States)

Kotval, P. S.

1971-01-01

Description of experiments in which prealloyed powders of superalloy compositions were consolidated by extrusion after the strengthening by precipitation of a body-centered tetragonal gamma secondary Ni3 Ta phase. Thin foil electron microscopy showed that the mechanical properties of the resultant powder-metallurgy product were correlated with its microstructure. The product exhibited high strength at 1200 F without loss of ductility, after thermomechanical treatment and aging.

Active Thermography for the Detection of Defects in Powder Metallurgy Compacts

International Nuclear Information System (INIS)

Benzerrouk, Souheil; Ludwig, Reinhold; Apelian, Diran

2007-01-01

Active thermography is an established NDE technique that has become the method of choice in many industrial applications which require non-contact access to the parts under test. Unfortunately, when conducting on-line infrared (IR) inspection of powder metallic compacts, complications can arise due the generally low emissivity of metals and the thermally noisy environment typically encountered in manufacturing plants. In this paper we present results of an investigation that explores the suitability of active IR imaging of powder metallurgy compacts for the detection of surface and sub-surface defects in the pre-sinter state and in an on-line manufacturing setting to ensure complete quality assurance. Additional off-line tests can be carried out for statistical quality analyses. In this research, the IR imaging of sub-surface defects is based on a transient instrumentation approach that relies on an electric control system which synchronizes and monitors the thermal response due to an electrically generated heat source. Preliminary testing reveals that this newly developed pulsed thermography system can be employed for the detection of subsurface defects in green-state parts. Practical measurements agree well with theoretical predictions. The inspection approach being developed can be used for the testing of green-state compacts as they exit the compaction press at speeds of up to 1,000 parts per hour

Microstructure and Aging of Powder-Metallurgy Al Alloys

Science.gov (United States)

Blackburn, L. B.

1987-01-01

Report describes experimental study of thermal responses and aging behaviors of three new aluminum alloys. Alloys produced from rapidly solidified powders and contain 3.20 to 5.15 percent copper, 0.24 to 1.73 percent magnesium, 0.08 to 0.92 percent iron, and smaller amounts of manganese, nickel, titanium, silicon, and zinc. Peak hardness achieved at lower aging temperatures than with standard ingot-metallurgy alloys. Alloys of interest for automobile, aircraft, and aerospace applications.

Damage on 316LN stainless steel transformed by powder metallurgy

International Nuclear Information System (INIS)

Couturier, R.; Burlet, H.

1998-01-01

This study deals with the 316 LN stainless steel elaboration by powder metallurgy. This method allows the realization of structures in austenitic steel less affected by the thermal aging than the cast austenitic-ferritic components. The components are performed by the method of HIP (Hot Isostatic Pressing). Mechanical tests are provided to control mechanical properties

In Vitro Antiviral Activity of Rubia Cordifolia Aerial Part Extract Against Rotavirus

Directory of Open Access Journals (Sweden)

Yuanyuan Sun

2016-09-01

Full Text Available The root of Rubia cordifolia (R. cordifolia has been used traditionally as a hemostatic agent, while the aerial part of the plant consisting of leaf and stem is known to exhibit anti-diarrheal properties and has been widely used as a remedy in many parts of China. As rotavirus is one of the most commonly associated diarrhea-causing pathogen, this study aims to investigate the anti-rotaviral effect of R. cordifolia aerial part (RCAP. The cytotoxicity of RCAP towards MA-104 cells was evaluated using the WST-8 assay. Colloidal gold method and real time polymerase chain reaction (qPCR assay were used to confirm the findings of the antiviral assay. Then, 4',6-diamidino-2-phenylindole (DAPI staining method was subsequently used to investigate the mode of death among the cells. And the representative components of aqueous extract were isolated and identified. It was shown that both the viability of MA-104 cells and the viral load were reduced with increasing concentration of the extract. DAPI staining showed that virus-induced apoptosis was the cause of the low cell viability and viral load, an effect which was accelerated with incubation in the aqueous herbal extract. The major compounds postulated to exhibit this activity were isolated from the aqueous herbal extract and identified to be compounds Xanthopurpurin and Vanillic Acid. This study showed that RCAP extract effectively inhibited rotavirus multiplication by promoting virus-induced apoptosis in MA-104 cells.

Evaluation of ethanol extract of Artemisia maciverae aerial part for ...

African Journals Online (AJOL)

christy

Evaluation of ethanol extract of Artemisia maciverae aerial part for antiplasmodial activity ... median lethal dose of A. maciverae in mice was determined to be greater than ... medicinal uses [9]. ..... mode of action and mechanism of resistance.

Gold 100: proceedings of the international conference on gold. V. 2

International Nuclear Information System (INIS)

Fivaz, C.E.; King, R.P.

1986-01-01

The proceedings of Gold 100 have been published in three separate volumes. The first deals with the mining of gold, the second with the extractive metallurgy of gold, and the third with industrial uses of gold. In this second volume, the papers on extractive metallurgy presented at the Conference reflect most of the problems that are currently of significant technical interest to the industry. This volume is divided in six main parts covering plant design, carbon-in-pulp technology, refractory gold, new technology, grinding and concentration, and leaching. The part on new technology includes papers on x-ray fluorescence analyzers, Moessbauer spectroscopy and leaching processes for uranium, while the part on grinding and concentration includes papers on nuclear and radiotracer techniques for the recovery of gold as well as various flotation parameters in the flotation behaviour of gold and uranium

The Hydrometallurgical Extraction and Recovery of High-Purity Silver

Science.gov (United States)

Hoffmann, James E.

2012-06-01

With the continuous reduction in the availability of extractive metallurgical curricula in colleges and universities, the concern has in part been from where will the next generation of extractive metallurgists come? One objective of this article is to emphasize the fact that extractive metallurgy is, in fact, one of many areas of chemical engineering technology. Thus, although the extractive metallurgist may have disappeared in name, its activity is alive and well, subsumed in the field of chemical engineering. One goal of this lecture is to demonstrate the applicability of chemical engineering principles to what is typically considered "the field of extractive metallurgy." Two processes will be described that have supplanted typical pyrometallurgical fire refining of precious metals, particularly silver. The origins of fire refining can be traced back to biblical times. There are numerous references to it in the old testament: Ezekiel 22:20, "As men gather silver and bronze and iron and lead and tin into a furnace to blow the fire upon it in order melt it"; Jeremiah 6:29, "The bellows blow fiercely; the lead is consumed by the fire; in vain the refining goes on"; and Malachi 3:2 (The Oxford Annotated Bible with the Apocrypha), "For he is like a refiners fire." Many references to it will also be found in "De Re Metallurgica" and as well in Lazarus Ercker's 1574 Manual "Treatise on Ores and Refining." Today, fire refining has been improved greatly by innovative furnace design, new fluxing technologies, and the improved use of oxygen. However, fundamentally, the process chemistry has not changed much in the last millennium. Illustrations of hydrometallurgical processing of silver-bearing inputs will be provided by the treatment of sulfated silver-bearing materials and chlorinated slimes. The first of these technologies will be described briefly as practiced by the Phelps Dodge Refining Corporation for several years. The second, the treatment of silver chloride

Anti-inflammatory and antinociceptive activities of Solenostemon monostachyus aerial part extract in mice

Directory of Open Access Journals (Sweden)

Jude Fiom Okokon

2016-04-01

Full Text Available Objective: Solenostemon monostachyus is used in traditional medicine for the treatment of various ailments such as ulcer, hypertension, pains and inflammatory diseases. Evaluation of anti-inflammatory and analgesic activities of S. monostachyus aerial parts was carried out to ascertain its uses in traditional medicine. Materials and Methods: The aerial parts of S. monostachyus was cold extracted by soaking the dried powdered material in ethanol. The aerial parts crude extract (75 –225 mg/kg of  S. monostachyus was investigated for analgesic and anti-inflammatory activities using various experimental models; acetic acid, formalin and thermal- induced pains models for analgesic study and carrageenin, egg albumin and xylene – induced edema models for anti-inflammatory investigation. Results: The extract caused a significant (pConclusion: The anti-inflammatory and analgesic effects of this plant may in part be mediated through the chemical constituents of the plant and the results of the analgesic action suggest central and peripheral mechanisms. The findings of this work confirm the ethno medical use of this plant to treat inflammatory conditions.

[Risk and features of occupational diseases in nonferrous metallurgy workers of Kolsky Transpolar area].

Science.gov (United States)

Siurin, S A; Chashchin, V P; Frolova, N M

2015-01-01

The study covered data on 977 cases of occupational diseases in 615 workers of nonferrous metallurgy in Kolsky Transpolar area. Findings are high risk of occupational diseases in workers engaged into electrolysis production of aluminium, all nickel reprocessing and pyrometallic copper reprocessing (GR 7.02-10.0). Electrolysis operators and anode operators of aluminium production are more prone to occupational diseases, with bone and muscular disorders (46.8%) prevalent in the morbidity structure. Respiratory diseases are more prevalent (68.2-100%) in the occupational morbidity structure of copper-nickelindustry workers. Conclusion is made on mandatory improvement of the work conditions and more effective individual protective means against occupational hazards in workers of nonferrous metallurgy in Kolsky Transpolar area.

Comprehensive waste characterization and organic pollution co-occurrence in a Hg and As mining and metallurgy brownfield

Energy Technology Data Exchange (ETDEWEB)

Gallego, J.R., E-mail: jgallego@uniovi.es [Environmental Technology, Biotechnology and Geochemistry Group, C/Gonzalo Gutiérrez Quirós s/n, 33600 Mieres, Asturias (Spain); Esquinas, N.; Rodríguez-Valdés, E.; Menéndez-Aguado, J.M. [Environmental Technology, Biotechnology and Geochemistry Group, C/Gonzalo Gutiérrez Quirós s/n, 33600 Mieres, Asturias (Spain); Sierra, C. [Environmental Technology, Biotechnology and Geochemistry Group, C/Gonzalo Gutiérrez Quirós s/n, 33600 Mieres, Asturias (Spain); Escuela Superior Politécnica del Litoral, Guayaquil (Ecuador)

2015-12-30

Highlights: • Complex legacy of contamination afflicts As–Hg brownfields. • As- and Hg-rich waste analyzed in a paradigmatic study site. • Co-ocurrence of a complex speciation of As and Hg, and organic pollution (PAHs). • Arsenolite was determined to be the main source of risk at the site. • Unexpected Hg organo-compounds found. - Abstract: The abandonment of Hg–As mining and metallurgy sites, together with long-term weathering, can dramatically degrade the environment. In this work it is exemplified the complex legacy of contamination that afflicts Hg–As brownfields through the detailed study of a paradigmatic site. Firstly, an in-depth study of the former industrial process was performed to identify sources of different types of waste. Subsequently, the composition and reactivity of As- and Hg-rich wastes (calcines, As-rich soot, stupp, and flue dust) was analyzed by means of multielemental analysis, mineralogical characterization (X-ray diffraction, electronic, and optical microscopy, microbrobe), chemical speciation, and sequential extractions. As-rich soot in the form of arsenolite, a relatively mobile by-product of the pyrometallurgical process, and stupp, a residue originated in the former condensing system, were determined to be the main risk at the site. In addition, the screening of organic pollution was also aimed, as shown by the outcome of benzo(a) pyrene and other PAHs, and by the identification of unexpected Hg organo-compounds (phenylmercury propionate). The approach followed unravels evidence from waste from the mining and metallurgy industry that may be present in other similar sites, and identifies unexpected contaminants overlooked by conventional analyses.

Thermogravimetric control of intermediate compounds in uranium metallurgy; Control termogravimetrico de productos intermedios de la metalurgia del uranio

Energy Technology Data Exchange (ETDEWEB)

Gasco Sanchez, L; Fernandez Cellini, R

1959-07-01

The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs.

Power metallurgy approaches to high temperature components for gas turbine engines

Science.gov (United States)

Probst, H. B.

1974-01-01

Work conducted by NASA and NASA contractors on prealloyed superalloy powders and materials strengthened by oxide dispersion is reviewed. Fabrication, tensile strength, superplasticity, grain growth control, stress rupture life, and grain-size and dispersion-level effects are covered. Distinct strength advantages of powder metallurgy superalloys over conventional wrought alloys are noted.

Alloy 800 - A review of properties and metallurgy

International Nuclear Information System (INIS)

Stone, P.G.; Orr, J.

1976-01-01

It is shown that the properties and metallurgy of alloy 800 are significantly influenced by relatively small changes in composition introduced by the nuclear industry in order to obtain better stress corrosion resistance. Two particular metallurgical effects are considered: the influence of lower TiC volume fraction on grain coarsening behavior and grain size; the influence of increased amounts of titanium in solid solution on Ni 3 (AlTi) precipitation. The first effect has a direct influence on proof stress properties, and the second on stress rupture strength and ductility. However, the important effect of aluminium on this behavior is emphasized. Other aspects considered are the effect of long reheating times during operation on proof strength and impact resistance. The final part of the paper deals with two fabrication aspects. After demonstrating the detrimental effect of cold working on stress rupture ductility, the susceptibility to premature failure is examined, using notched stress rupture specimens. Although notch sensitivity was found in short term tests, additional work suggests that it may not occur after longer testing times. The effect of stress relieving on this behavior is reported. The welding aspects considered include the compositional factors influencing liquation cracking, grain growth during welding, and the proof strength and stress rupture properties of welded material

PROCESSING OF SOFT MAGNETIC MATERIALS BY POWDER METALLURGY AND ANALYSIS OF THEIR PERFORMANCE IN ELECTRICAL MACHINES

Directory of Open Access Journals (Sweden)

W. H. D. Luna

2017-12-01

Full Text Available This article presents the use of finite elements to analyze the yield of electric machines based on the use of different soft magnetic materials for the rotor and the stator, in order to verify the performance in electric machine using powder metallurgy. Traditionally, the cores of electric machines are built from rolled steel plates, thus the cores developed in this work are obtained from an alternative process known as powder metallurgy, where powders of soft magnetic materials are compacted and sintered. The properties of interest were analyzed (magnetic, electric and mechanical properties and they were introduced into the software database. The topology of the rotor used was 400 W three-phase synchronous motor manufactured by WEG Motors. The results show the feasibility to replace the metal sheets of the electric machines by solid blocks obtained by powder metallurgy process with only 0.37% yield losses. In addition, the powder metallurgical process reduces the use of raw materials and energy consumption per kg of raw material processed.

[Analysis of changes in characteristics of arterial hypertension occupational risk in workers of nonferrous metallurgy].

Science.gov (United States)

Vlasova, E M; Shliapnikov, D M; Lebedeva, T M

2015-01-01

The article covers changes in occupational cardiovascular risk for workers of nonferrous,metallurgy. Findings are that exposure to noise up to 94 dB with length of service increases possible atherosclerosis and metabolic syndrome. With 5 years of service, risk of the predicted conditions increases by 40.5%. When occupational exposure lasts over 5 years, risk of arterial hypertension increases. A group of workers without exposure to occupational factors appeared to have no connection between length of service and metabolic syndrome and arterial hypertension. Risk evolution modelling proved that risk of functional disorders in nonferrous metallurgy workers becomes unacceptable after 5 years of service (cardiovascular disorders are critical).

Characterization of strengthening mechanism and hot deformation behavior of powder metallurgy molybdenum

International Nuclear Information System (INIS)

Xiao, Meili; Li, Fuguo; Xie, Hangfang; Wang, Yufeng

2012-01-01

Highlights: → Dynamic recrystallization of powder metallurgy molybdenum occurs in the temperature region (1200-1450 o C). → The value of strain hardening index n decreases along with the temperature rising. → The value of strain-rate sensitivity exponent m increases slowly at first and achieves a peak value at 1350 o C. → Deformation strengthening is the main strengthening mechanism at low temperature. → Rheological strengthening becomes the primary strengthening mechanism at high temperature. -- Abstract: The high-temperature deformation behavior of powder metallurgy molybdenum has been investigated based on a series of isothermal hot compression tests, which were carried out on a Gleeble-1500 thermal mechanical simulator in a wide range of temperatures (900-1450 o C) and strain rates (0.01-10 s -1 ). Through the research on the experimental stress-strain curves, it reveals that dynamic recrystallization softening effect of powder metallurgy molybdenum occurs in the temperature range from 1200 o C to 1450 o C, in which the flow stress is significantly sensitive to temperature. In comparison with the value of strain hardening index n which decreases along with the temperature rising, the value of strain-rate sensitivity exponent m does not change obviously; however, it increases slowly with the increasing of temperature at first and achieves a peak value at 1350 o C. Furthermore, relying on the comparison of mean value of n and m, it is suggested that deformation strengthening is the main strengthening mechanism at low temperature while the rheological strengthening changes into the primary strengthening mechanism at high temperature.

Thermogravimetric control of intermediate compounds in uranium metallurgy; Control termogravimetrico de productos intermedios de la metalurgia del uranio

Energy Technology Data Exchange (ETDEWEB)

Gasco Sanchez, L.; Fernandez Cellini, R.

1959-07-01

The thermal decomposition of some intermediate compounds in the metallurgy of the uranium as uranium peroxide, ammonium uranate, uranium and ammonium penta-fluoride, uranium tetrafluoride and uranous oxide has been study by means of the Chevenard's thermo balance. Some data on pyrolysis of synthetic mixtures of intermediate compounds which may occasionally appear during the industrial process, are given. Thermogravimetric methods of control are suggested, usable in interesting products in the uranium metallurgy. (Author) 20 refs.

Antimicrobial Activity of Aerial Part Crude Extracts from the Saharan plant Anabasis aretioides

Directory of Open Access Journals (Sweden)

A. AMARI

2015-03-01

Full Text Available The antimicrobial activity of several crude extracts from the aerial parts of Anabasis aretioides was investigated by the disc diffusion method. The S. aureus, C. albicans and S. cereviceae Bacteria showed good efficiency in bacterial activity with most of the tested extract.

Solvent extraction equipment evaluation study. Part 1. Review of the literature

Energy Technology Data Exchange (ETDEWEB)

Geier, R.G.; Browne, L.M. (comps.)

1977-01-01

This is Part 1 of a three-part document that reviews the solvent extraction contactors available for use in radiochemical reprocessing plants. The three parts are: Part 1: A Review of the Literature, Part 2: Workshop Proceedings, Part 3: A Summary. The main objective of the document is to provide an information base to aid in contactor selection and design of future reprocessing plants. The Literature Review (Part 1) brings together scattered data on all major contactors in use today. It contains an annotated bibliography of the citations used in the review and a complete listing of all the citations screened prior to the review. These bibliographies should aid in determining which reports would be most useful if additional information is desired.

Solvent extraction equipment evaluation study. Part 1. Review of the literature

International Nuclear Information System (INIS)

Geier, R.G.; Browne, L.M.

1977-01-01

This is Part 1 of a three-part document that reviews the solvent extraction contactors available for use in radiochemical reprocessing plants. The three parts are: Part 1: A Review of the Literature, Part 2: Workshop Proceedings, Part 3: A Summary. The main objective of the document is to provide an information base to aid in contactor selection and design of future reprocessing plants. The Literature Review (Part 1) brings together scattered data on all major contactors in use today. It contains an annotated bibliography of the citations used in the review and a complete listing of all the citations screened prior to the review. These bibliographies should aid in determining which reports would be most useful if additional information is desired

Powder metallurgy approaches to high temperature components for gas turbine engines

Science.gov (United States)

Probst, H. B.

1974-01-01

Research is reported for the tensile strength, ductility, and heat performance characterisitics of powder metallurgy (p/m) superalloys. Oxide dispersion strengthened alloys were also evaluated for their strength during thermal processing. The mechanical attributes evident in both p/m supperalloys and dispersion strengthened alloys are discussed in terms of research into their possible combination.

Microstructural and mechanical characteristics of porous iron prepared by powder metallurgy.

Science.gov (United States)

Capek, Jaroslav; Vojtěch, Dalibor

2014-10-01

The demand for porous biodegradable load-bearing implants has been increasing recently. Based on investigations of biodegradable stents, porous iron may be a suitable material for such applications. In this study, we prepared porous iron samples with porosities of 34-51 vol.% by powder metallurgy using ammonium bicarbonate as a space-holder material. We studied sample microstructure (SEM-EDX and XRD), flexural and compressive behaviors (universal loading machine) and hardness HV5 (hardness tester) of the prepared samples. Sample porosity increased with the amount of spacer in the initial mixtures. Only the pore surfaces had insignificant oxidation and no other contamination was observed. Increasing porosity decreased the mechanical properties of the samples; although, the properties were still comparable with human bone and higher than those of porous non-metallic biomaterials and porous magnesium prepared in a similar way. Based on these results, powder metallurgy appears to be a suitable method for the preparation of porous iron for orthopedic applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Biaxially textured articles formed by powder metallurgy

Science.gov (United States)

Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

2003-07-29

A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

Biaxially textured articles formed by power metallurgy

Science.gov (United States)

Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

2003-08-26

A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of mixtures consisting of: at least 60 at % Ni powder and at least one of Cr powder, W powder, V powder, Mo powder, Cu powder, Al powder, Ce powder, YSZ powder, Y powder, Mg powder, and RE powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

Biaxially textured articles formed by powder metallurgy

Science.gov (United States)

Goyal, Amit; Williams, Robert K.; Kroeger, Donald M.

2003-08-05

A biaxially textured alloy article having a magnetism less than pure Ni includes a rolled and annealed compacted and sintered powder-metallurgy preform article, the preform article having been formed from a powder mixture selected from the group of ternary mixtures consisting of: Ni powder, Cu powder, and Al powder, Ni powder, Cr powder, and Al powder; Ni powder, W powder and Al powder; Ni powder, V powder, and Al powder; Ni powder, Mo powder, and Al powder; the article having a fine and homogeneous grain structure; and having a dominant cube oriented {100} orientation texture; and further having a Curie temperature less than that of pure Ni.

Quality-oriented production of brown-coal coke with due regard to its application in metallurgy and environmental protection; Qualitaetsgerechte Erzeugung von Braunkohlenkoks unter Beruecksichtigung der Anwendung in Metallurgie und Umweltschutz

Energy Technology Data Exchange (ETDEWEB)

Achtelik, M.; Erken, M.; Juessen, P.; Knapp, A. [Rheinbraun AG, Koeln (Germany)

1998-12-31

In the nineteen seventies the Fortuna Nord refining factory of Rheinbraun AG began to restructure its operations from domestic coal briquetting to the manufacture of industrial products. One of these products, high-temperature brown-coal coke, is produced in two hearth-type furnaces. Coke produced in these plants is mainly used in metallurgy and environmental engineering, in the latter especially for flue gas purification. Rheinbraun has succeeded in introducing a quality management system for brown-coal coke which ensures high quality and security of supply. (orig.) [Deutsch] Im Veredlungsbetrieb Fabrik Fortuna-Nord der Rheinbraun AG begann in den 70er Jahren der Strukturwandel vom Hausbrandbrikett zu Industrieprodukten. Eins dieser Produkte, der Hochtemperatur-Braunkohlenkoks, wird in zwei Herdofenanlagen erzeugt. Die Haupteinsatzbereiche des Herdofenkokses sind die Metallurgie sowie der Umweltschutz und hier insbesondere die Rauchgasreinigung. Um die hohe Produktqualitaet und die Liefersicherheit zu gewaehrleisten, hat Rheinbraun ein Qualitaetsmanagementsystem fuer Braunkohlenkoks erfolgreich eingefuehrt. (orig.)

State-of-the-art and main options to improve fuel-energy complex of ferrous metallurgy

Energy Technology Data Exchange (ETDEWEB)

Rozenblit, G I; Pashkov, V D; Romanov, G M

1981-01-01

In 1980, the State Institute for the Design and Planning Metallury (Gripromez), elaborated ''The main options of Fuel and energy resources conservation (FERG) in ferrous metallurgy of the USSR program of works for the period 1981-1985 and up to 1990''. The Gipromez technical committee recommended: 1) elaborating feasibility studies and reports, developing branch schemes and starting complexes to separate out FERC measures; 2) inclusion of the FERC measures at the starting complexes as the first stages of main projects construction; 3) that the Ministy of Ferrous Metallurgy of the USSR, general designers and enterprises reconsider the starting complexes of the projects constructed during the present five-year period and incorporate in them the urgent FERC actions on heat-utilizing facilities. Changing the steel smelting process structure through more extensive use of the converter process and installation of continuous blank casting allows achievement of considerable fuel conservation, some 4 m trf per year as compared with its consumption in the scheme of open-hearth furnace - blooming mill (slabbing mill). During the 11th five-year-plan period introduction of metallurgy plant. An installation with discharge of the converter gas without its afterburning and successive utilization as a fuel in the converter shop of the Novolipetsk is planned.

Beta Ti-45Nb and Ti-50Nb alloys produced by powder metallurgy for aerospace application

Energy Technology Data Exchange (ETDEWEB)

Martins, G.V.; Trava-Airoldi, V.J.; Machado, J.P.B., E-mail: givmartins@yahoo.com.br, E-mail: vladimir@las.inpe.br, E-mail: joaopaulo@las.inpe.br [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Silva, C.R.M., E-mail: cosmeroberto@gmail.com [Universidade de Brasilia (UnB), Brasilia, DF (Brazil); Nunes, C.A., E-mail: cnunes@demar.eel.usp.br [Universidade de Sao Paulo (EEL/USP), Lorena, SP (Brazil). Polo Urbo Industrial; Borges Junior, L.A., E-mail: borges.jr@itelefonica.com.br [Centro Universitario de Volta Redond (UNIFOA), Volta Redonda, RJ (Brazil)

2009-07-01

Beta titanium alloys parts are used on advanced aerospace systems because of their high strength to weight ratio and excellent corrosion resistance. Production of powder metallurgy titanium alloys components may lead to a substantial reduction in the cost, compared to those produced by conventional cast and wrought processes, because additional working operations and material waste can be avoided. In this work, beta Ti-45Nb and Ti- 50Nb were produced by the blended elemental technique, followed by uniaxial and cold isostatic pressing with subsequent densification by sintering. Sintered samples were characterized for phase composition by XRD, microstructure by SEM, hardness by Vickers indentation, specific mass by the Archimedes method and elastic modulus by resonance ultrasound. The sintered samples presented only the beta phase, higher hardness and lower elastic modulus when compared to Ti6Al4V alloy and experimental specific mass value near theoretical specific mass. These characteristics are adequate for application on several aerospace parts. (author)

Beta Ti-45Nb and Ti-50Nb alloys produced by powder metallurgy for aerospace application

International Nuclear Information System (INIS)

Martins, G.V.; Trava-Airoldi, V.J.; Machado, J.P.B.; Silva, C.R.M.; Nunes, C.A.

2009-01-01

Beta titanium alloys parts are used on advanced aerospace systems because of their high strength to weight ratio and excellent corrosion resistance. Production of powder metallurgy titanium alloys components may lead to a substantial reduction in the cost, compared to those produced by conventional cast and wrought processes, because additional working operations and material waste can be avoided. In this work, beta Ti-45Nb and Ti- 50Nb were produced by the blended elemental technique, followed by uniaxial and cold isostatic pressing with subsequent densification by sintering. Sintered samples were characterized for phase composition by XRD, microstructure by SEM, hardness by Vickers indentation, specific mass by the Archimedes method and elastic modulus by resonance ultrasound. The sintered samples presented only the beta phase, higher hardness and lower elastic modulus when compared to Ti6Al4V alloy and experimental specific mass value near theoretical specific mass. These characteristics are adequate for application on several aerospace parts. (author)

Uranium mining and metallurgy library science and technology literature retrieval of network

International Nuclear Information System (INIS)

Tang Lilei

2014-01-01

This paper introduces the network resources and characteristics retrieve service of Beijing research Institute of Chemical Engineering of Metallurgy library, Analyzes the problems often encountered in the literature retrieval in science and technology, And puts forward the solution, Puts forward the thinking and Suggestions of science and technology literature retrieval. (author)

Estimation and characterization of polycyclic aromatic hydrocarbons from magnesium metallurgy facilities in China.

Science.gov (United States)

Nie, Zhiqiang; Yang, Yufei; Tang, Zhenwu; Liu, Feng; Wang, Qi; Huang, Qifei

2014-11-01

Field monitoring was conducted to develop a polycyclic aromatic hydrocarbon (PAH) emission inventory for the magnesium (Mg) metallurgy industry in China. PAH emissions in stack gas and fly/bottom ash samples from different smelting units of a typical Mg smelter were measured and compared. Large variations of concentrations, congener patterns, and emission factors of PAHs during the oxidation and reduction stages in the Mg smelter were observed. The measured average emission factor (166,487 μg/t Mg) was significantly higher than those of other industrial sources. Annual emission from Mg metallurgy in 2012 in China was estimated at 116 kg (514 g BaPeq) for PAHs. The results of this study suggest that PAH emission from Mg industries should be considered by local government agencies. These data may be helpful for understanding PAH levels produced by the Mg industry and in developing a PAH inventory.

The beginning of metallurgy in the southern Levant: a late 6th millennium CalBC copper awl from Tel Tsaf, Israel.

Science.gov (United States)

Garfinkel, Yosef; Klimscha, Florian; Shalev, Sariel; Rosenberg, Danny

2014-01-01

The beginning of metallurgy in the ancient Near East attracts much attention. The southern Levant, with the rich assemblage of copper artifacts from the Nahal Mishmar cave and the unique gold rings of the Nahal Qanah cave, is regarded as a main center of early metallurgy during the second half of the 5th millennium CalBC. However, a recently discovered copper awl from a Middle Chalcolithic burial at Tel Tsaf, Jordan Valley, Israel, suggests that cast metal technology was introduced to the region as early as the late 6th millennium CalBC. This paper examines the chemical composition of this item and reviews its context. The results indicate that it was exported from a distant source, probably in the Caucasus, and that the location where it was found is indicative of the social status of the buried individual. This rare finding indicates that metallurgy was first diffused [corrected] to the southern Levant through exchange networks and only centuries later involved local productionThis copper awl, the earliest metal artifact found in the southern Levant, indicates that the elaborate Late Chalcolithic metallurgy developed from a more ancient tradition.

In vitro antioxidant and antiproliferative activities of methanolic plant part extracts of Theobroma cacao.

Science.gov (United States)

Baharum, Zainal; Akim, Abdah Md; Taufiq-Yap, Yun Hin; Hamid, Roslida Abdul; Kasran, Rosmin

2014-11-10

The aims of this study were to determine the antioxidant and antiproliferative activity of the following Theobroma cacao plant part methanolic extracts: leaf, bark, husk, fermented and unfermented shell, pith, root, and cherelle. Antioxidant activity was determined using 2,2-diphenyl-2-picrylhydrazyl (DPPH), thiobarbituric acid-reactive substances (TBARS), and Folin-Ciocalteu assays; the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium (MTT) assay was used to determine antiproliferative activity. The root extract had the highest antioxidant activity; its median effective dose (EC50) was 358.3±7.0 µg/mL and total phenolic content was 22.0±1.1 g GAE/100 g extract as compared to the other methanolic plant part extracts. Only the cherelle extract demonstrated 10.4%±1.1% inhibition activity in the lipid peroxidation assay. The MTT assay revealed that the leaf extract had the highest antiproliferative activity against MCF-7 cells [median inhibitory concentration (IC50)=41.4±3.3 µg/mL]. Given the overall high IC50 for the normal liver cell line WRL-68, this study indicates that T. cacao methanolic extracts have a cytotoxic effect in cancer cells, but not in normal cells. Planned future investigations will involve the purification, identification, determination of the mechanisms of action, and molecular assay of T. cacao plant extracts.

In Vitro Antioxidant and Antiproliferative Activities of Methanolic Plant Part Extracts of Theobroma cacao

Directory of Open Access Journals (Sweden)

Zainal Baharum

2014-11-01

Full Text Available The aims of this study were to determine the antioxidant and antiproliferative activity of the following Theobroma cacao plant part methanolic extracts: leaf, bark, husk, fermented and unfermented shell, pith, root, and cherelle. Antioxidant activity was determined using 2,2-diphenyl-2-picrylhydrazyl (DPPH, thiobarbituric acid-reactive substances (TBARS, and Folin-Ciocalteu assays; the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium (MTT assay was used to determine antiproliferative activity. The root extract had the highest antioxidant activity; its median effective dose (EC50 was 358.3 ± 7.0 µg/mL and total phenolic content was 22.0 ± 1.1 g GAE/100 g extract as compared to the other methanolic plant part extracts. Only the cherelle extract demonstrated 10.4% ± 1.1% inhibition activity in the lipid peroxidation assay. The MTT assay revealed that the leaf extract had the highest antiproliferative activity against MCF-7 cells [median inhibitory concentration (IC50 = 41.4 ± 3.3 µg/mL]. Given the overall high IC50 for the normal liver cell line WRL-68, this study indicates that T. cacao methanolic extracts have a cytotoxic effect in cancer cells, but not in normal cells. Planned future investigations will involve the purification, identification, determination of the mechanisms of action, and molecular assay of T. cacao plant extracts.

Factors Influencing Dwell Fatigue Cracking in Notches of Powder Metallurgy Superalloys

Science.gov (United States)

Gabb, T. P.; Telesman, J.; Ghosn, L.; Garg, A.; Gayda, J.

2011-01-01

The influences of heat treatment and cyclic dwells on the notch fatigue resistance of powder metallurgy disk superalloys were investigated for low solvus high refractory (LSHR) and ME3 disk alloys. Disks were processed to produce material conditions with varied microstructures and associated mechanical properties. Notched specimens were first subjected to baseline dwell fatigue cycles having a dwell at maximum load, as well as tensile, stress relaxation, creep rupture, and dwell fatigue crack growth tests at 704 C. Several material heat treatments displayed a bimodal distribution of fatigue life with the lives varying by two orders-of-magnitude, while others had more consistent fatigue lives. This response was compared to other mechanical properties, in search of correlations. The wide scatter in baseline dwell fatigue life was observed only for material conditions resistant to stress relaxation. For selected materials and conditions, additional tests were then performed with the dwells shifted in part or in total to minimum tensile load. The tests performed with dwells at minimum load exhibited lower fatigue lives than max dwell tests, and also exhibited early crack initiation and a substantial increase in the number of initiation sites. These results could be explained in part by modeling evolution of peak stresses in the notch with continued dwell fatigue cycling. Fatigue-environment interactions were determined to limit life for the fatigue cycles with dwells.

Structural and electrical properties of copper-nickel-aluminum alloys obtained by conventional powder metallurgy method

International Nuclear Information System (INIS)

Monteiro, Waldemar A.; Carrio, Juan A.G.; Silveira, C.R. da; Pertile, H.K.S.

2009-01-01

This work looked for to search out systematically, in scale of laboratory, copper-nickel-aluminum alloys (Cu-Ni-Al) with conventional powder metallurgy processing, in view of the maintenance of the electric and mechanical properties with the intention of getting electric connectors of high performance or high mechanical damping. After cold uniaxial pressing (1000 kPa), sintering (780 deg C) and convenient homogenization treatments (500 deg C for different times) under vacuum (powder metallurgy), the obtained Cu-Ni-Al alloys were characterized by optical microscopy, electrical conductivity, Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, hardness, macrostructures and microstructures of the samples. (author)

Metallurgy Department. Progress Report for the Period 1 January to 31 December 1984

DEFF Research Database (Denmark)

Risø National Laboratory, Roskilde

The activities of the Metallurgy Department at Risø during 1984 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, and Fuel Elements. A survey is given of the Department's participation in international collaboration and of its...

Powder metallurgy development at SRL

International Nuclear Information System (INIS)

Peacock, H.B.

1978-01-01

Fuel for Savannah River Plant (SRP) reactors consists of extruded tubes with aluminum--uranium alloy cores clad with 8001 aluminum. The 235 U in the fuel is periodically recovered and recycled in new fuel assemblies. The buildup of 236 U in the enriched uranium requires increased total uranium contents to maintain reactivity in existing assembly designs. High level waste production from these tubes is proportional to the aluminum content; therefore, appreciable radioactive waste reductions result from lower aluminum--uranium ratios and thinner clad tubes. The casting process now used for fuel cores is limited to below 40 wt % U because of the reduced fabricability of high uranium alloys. To increase tube loading and reduce aluminum, the U 3 O 8 -Al powder metallurgy (P/M) process for fuel tubes is under development. Several fabricaion and irradiaion tests have been made using production conditions. Both small scale and production tests carried out at SRL for high-density P/M fuel development are discussed

Al/ B4C Composites with 5 and 10 wt% Reinforcement Content Prepared by Powder Metallurgy

International Nuclear Information System (INIS)

Yusof Abdullah; Mohd Reusmaazran Yusof; Azali Muhammad; Nadira Kamarudin; Wilfred Sylvester Paulus; Roslinda Shamsudin; Nasrat Hannah Shudin; Nurazila Mat Zali

2012-01-01

The preparation, physical and mechanical properties of Al/ B 4 C composites with 5 and 10 wt.% reinforcement content were investigated. In order to obtain the feedstock with a low powder loading, B 4 C mixtures containing fine powders were investigated to obtain the optimal particle packing. The experimental results indicated that the fine containing 5 and 10 wt.% particles are able to prepare the feedstock with a good flowability. The composites fabricated by powder metallurgy have low densities and homogeneous microstructures. Additionally there is no interface reaction observed between the reinforcement and matrix by XRD analysis. The hardness of Al/ B 4 C composites prepared by powder metallurgy was high. (Author)

[Investigation about prevention behavior for dust workers in machinery, ceramic, and metallurgy industry].

Science.gov (United States)

Shen, Fu-hai; Ma, Qing-kun; Xiao, Shu-yu; Cui, Feng-tao; Meng, Qing-di; Yang, Xiu-qing; Qi, Hui-sheng; Fan, Xue-yun; Yao, San-qiao

2011-01-01

The purposes of this thesis were to study the behavior about workers exposed to dust and provide scientific basis for health promotion. We designed a questionnaire and carry it on the 746 dust workers in the 3 representative corporations of Machinery, Ceramic, and Metallurgy Industry. All data were input into computer. And a database was established with Excel. SPSS11.5 statistical analysis software was used to analyze the influence on protecting behavioral between the application of qualifications, different jobs, training or protection, and other aspects etc. The rates were 94.4% and 75.3% about the regular physical examination and requirements for protective equipment. The rate of choosing an effective way of protection was generally low (15.4%). There was significant difference for among different educational background workers (P Metallurgy Industry. Those who were not educated had a lower using rate about the protection behavior, regular physical examination, and requirements for protective equipment than those educated.

Development of structural diagram of automated dispatch control system for power consumption at non-ferrous metallurgy enterprises

Science.gov (United States)

Klyuev, R. V.; Bosikov, I. I.; Madaeva, M. Z.; A-V Turluev, R.

2018-03-01

The structural scheme of the automated control system of power consumption at the industrial enterprise is developed in the article. At the non-ferrous metallurgy enterprise, an energy inspection and a rank analysis of the electrical energy consumption of the main processing equipment were carried out. It is established that the enterprises of non-ferrous metallurgy are a complex process system consisting of a set of thousands of jointly functioning technological facilities. For the most effective estimation of power consumption of enterprises, it is reasonable to use the automated system of dispatching control of power consumption (ASDCPC). The paper presents the results of the development of the ASDCPC structural diagram that allows one to perform on-line control and management of the energy and process parameters of the main production units and the enterprise as a whole. As a result of the introduction of ASDCPC at the non-ferrous metallurgy enterprise, the consumed active power was reduced during the peak hours of the load by 20%, the specific electricity consumption - by 14%, the cost of the energy component in the cost of production of hard alloys - by 3%.

Characterization of Powder Metallurgy Processed Pure Magnesium Materials for Biomedical Applications

Czech Academy of Sciences Publication Activity Database

Březina, M.; Minda, J.; Doležal, P.; Krystýnová, M.; Fintová, Stanislava; Zapletal, J.; Wasserbauer, J.; Ptáček, P.

2017-01-01

Roč. 7, č. 11 (2017), č. článku 461. ISSN 2075-4701 Institutional support: RVO:68081723 Keywords : magnesium * powder metallurgy * cold pressing * hot pressing * EIS (Electrochemical impedance spectroscopy) * three-point bending test * corrosion Subject RIV: JK - Corrosion ; Surface Treatment of Materials OBOR OECD: Coating and films Impact factor: 1.984, year: 2016 http://www.mdpi.com/2075-4701/7/11/461

Biological Activities and Phytochemical Profiles of Extracts from Different Parts of Bamboo (Phyllostachys pubescens

Directory of Open Access Journals (Sweden)

Akinobu Tanaka

2014-06-01

Full Text Available Besides being a useful building material, bamboo also is a potential source of bioactive substances. Although some studies have been performed to examine its use in terms of the biological activity, only certain parts of bamboo, especially the leaves or shoots, have been studied. Comprehensive and comparative studies among different parts of bamboo would contribute to a better understanding and application of this knowledge. In this study, the biological activities of ethanol and water extracts from the leaves, branches, outer culm, inner culm, knots, rhizomes and roots of Phyllostachys pubescens, the major species of bamboo in Japan, were comparatively evaluated. The phytochemical profiles of these extracts were tentatively determined by liquid chromatography-mass spectrometry (LC-MS analysis. The results showed that extracts from different parts of bamboo had different chemical compositions and different antioxidative, antibacterial and antiallergic activities, as well as on on melanin biosynthesis. Outer culm and inner culm were found to be the most important sources of active compounds. 8-C-Glucosylapigenin, luteolin derivatives and chlorogenic acid were the most probable compounds responsible for the anti-allergy activity of these bamboo extracts. Our study suggests the potential use of bamboo as a functional ingredient in cosmetics or other health-related products.

Application of the ecologically clean technology of mining metallurgy and power industry wastes recycling based on the use of electron beams

International Nuclear Information System (INIS)

Mazhrenova, N.R.; Askarova, G.Sh.

1997-01-01

Advantage of electron beam technologies application for industrial wastes recycling is illustrated for following trends: 1).Off gases of mining metallurgy and the thermal power plant can be refined from SO 2 and NO x toxic combination by means of their further chemical and radiation oxidation with following obtaining of acids on the base industrial accelerator ELV-8. In this method a radiation-chemical process in irradiated gas results in excited complexes, radicals and ion formation. Ion cause the activation of reaction chain which convert SO 2 and NO x toxic gases into the combination with high number of oxidation. In presence of water, coming from drip cooler, the combination of sulphuric and nitric acids neutralization results in the obtaining of ammonium solid combination which are mainly sulphates and nitrates; 2). For waste water refinement from organic pollution, for instance butyl xanthate, ions of heavy metals and etc.; 3). For non-ferrous, sparse and and dispersed metal extraction from the cinder and slag wastes. Different technological schemes for mineral extraction are elaborated

Minimization of radioactive solid wastes from uranium mining and metallurgy

International Nuclear Information System (INIS)

Zhang Xueli; Xu Lechang; Wei Guangzhi; Gao Jie; Wang Erqi

2010-01-01

The concept and contents of radioactive waste minimization are introduced. The principle of radioactive waste minimization involving administration optimization, source reduction, recycling and reuse as well as volume reduction are discussed. The strategies and methods to minimize radioactive solid wastes from uranium mining and metallurgy are summarized. In addition, the benefit from its application of radioactive waste minimization is analyzed. Prospects for the research on radioactive so-lid waste minimization are made in the end. (authors)

Powder Metallurgy Reconditioning of Food and Processing Equipment Components

Science.gov (United States)

Nafikov, M. Z.; Aipov, R. S.; Konnov, A. Yu.

2017-12-01

A powder metallurgy method is developed to recondition the worn surfaces of food and processing equipment components. A combined additive is composed to minimize the powder losses in sintering. A technique is constructed to determine the powder consumption as a function of the required metallic coating thickness. A rapid method is developed to determine the porosity of the coating. The proposed technology is used to fabricate a wear-resistant defectless metallic coating with favorable residual stresses, and the adhesive strength of this coating is equal to the strength of the base metal.

Application of powder metallurgy in production of nuclear fuels for research and power reactors

International Nuclear Information System (INIS)

Fukuda, Kosaku

2000-01-01

Powder metallurgy has been applied in many of the processes of nuclear fuel fabrication, which has contributed, to a great progress of the nuclear technology to date. Evolution of nuclear fuels still continues to meet various emerging demands in terms of enhanced safety, economical effectiveness, non-proliferation and environmental mitigation. This paper reviews recent progress of nuclear fuels of research and power reactors, in particular, focusing on the powder metallurgy application. First, the review is made on plate type fuels for research reactors, inter alia, silicide fuel which is prevailing worldwide from the viewpoint of non-proliferation. The relation between fabrication and irradiation behavior is also discussed. Next, oxide fuels including MOX are reviewed. Recent interests of UO 2 are directed toward large grain pellets and burnable absorber pellets, both of which arise from requirement of extended burnup. Finally, the MOX fuel for thermal reactors is reviewed. (author)

Obtainment of the alloy Cu13Al4Ni using processed by powder metallurgy

International Nuclear Information System (INIS)

Grossi, L.J.; Damasceno, N.; Muterlle, P.V.

2016-01-01

The powder metallurgy is a technique environmentally advantageous that allows the production of many pieces, with a good superficial finishing and dimensional tolerance. For the production of pieces using technique, basics steps are carried out, as the characterization of powders, the mixing and homogenization, compacting and sintering. In this context, this work has as objective the obtainment of the Cu13Al4Ni alloy via powder metallurgy. For this, was made a high energy milling for 2, 4 and 8 hours. Then, the milled powder was compacted and posteriorly, sintered in an oven with controlled atmosphere. It was observed that the milling time affects directly in sintering of the pieces. The best results obtained were for the samples that were milled for 4 hours. This samples have showed 21, 52% of porosity and 6,382 g/cm³ of the density of sintered. (author)

Properties of porous magnesium prepared by powder metallurgy.

Science.gov (United States)

Čapek, Jaroslav; Vojtěch, Dalibor

2013-01-01

Porous magnesium-based materials are biodegradable and promising for use in orthopaedic applications, but their applications are hampered by their difficult fabrication. This work reports the preparation of porous magnesium materials by a powder metallurgy technique using ammonium bicarbonate as spacer particles. The porosity of the materials depended on the amount of ammonium bicarbonate and was found to have strong negative effects on flexural strength and corrosion behaviour. However, the flexural strength of materials with porosities of up to 28 vol.% was higher than the flexural strength of non-metallic biomaterials and comparable with that of natural bone. Copyright © 2012 Elsevier B.V. All rights reserved.

Annual report of the Metallurgy Division - period ending December 1975

International Nuclear Information System (INIS)

1976-01-01

The R and D activities of the Metallurgy Division of the Bhabha Atomic Research Centre, Bombay (India) during 1975 are described. Some of the R and D programmes of particular interest to nuclear technology are: (1) flowsheet development for the production of rare metals and alloys of nuclear use e.g. hafnium, beryllium, zirconium (2) metallurgical, irradiation hardening and corrosion studies on Zr and Zr-base alloys and (3) studies of nuclear ceramic materials such as UO2 and beryllia. (M.G.B.)

Antihyperlipidemic, Antioxidant and Cytotoxic Activities of Methanolic and Aqueous Extracts of Different Parts of Star Fruit.

Science.gov (United States)

Saghir, Sultan A M; Sadikun, Amirin; Al-Suede, Fouad S R; Majid, Amin M S A; Murugaiyah, Vikneswaran

Star fruit (Averrhoa carambola) is a well-known plant in Malaysia which bears a great significance in traditional medicine. This study aimed to evaluate the antihyperlipidemic effect, antioxidant potential and cytotoxicity of aqueous and methanolic extracts of ripe and unripe fruits, leaves and stem of A. carambola. Antihyperlipidemic activity was assessed in poloxamer-407 (P-407) induced acute hyperlipidemic rat's model. The antioxidant activity was assessed in vitro using 2, 2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging, 1-diphenyl-2-dipicrylhydrazyl radical scavenging (DPPH) and ferric reducing antioxidant power (FRAP) assays. In addition, cytotoxicity of A. carambola extracts was assessed using MTS assay on four leukemic cell lines (human colon cancer, human promyeloid leukemia, erythroid leukemia, acute myeloid leukemia) and one normal cell (human umbilical vein endothelial cells). Methanolic extract of leaves had the most potent antihyperlipidemic activity in P-407 model, whereby it significantly reduced serum levels of total cholesterol (Pcarambola stem and leaves showed the strongest antioxidant activity. Total phenolic and flavonoid contents of the extracts exhibited significant correlations with antioxidant but not with antihyperlipidemic activities. All plant parts showed no cytotoxic effect on the selected cancer or normal cell lines. Antihyperlipidemic activity of different parts of A. carambola is greatly affected by extraction solvents used. Methanolic extract of A. carambola leaves exhibited higher antihyperlipidemic and antioxidant potentials compared to other parts of the plant.

The potential for portable X-ray fluorescence determination of soil copper at ancient metallurgy sites, and considerations beyond measurements of total concentrations.

Science.gov (United States)

Tighe, M; Rogan, G; Wilson, S C; Grave, P; Kealhofer, L; Yukongdi, P

2018-01-15

Copper (Cu) at ancient metallurgy sites represents the earliest instance of anthropogenically generated metal pollution. Such sites are spread across a wide range of environments from Eurasia to South America, and provide a unique opportunity to investigate the past and present extent and impact of metalworking contamination. Establishing the concentration and extent of soil Cu at archaeometallurgy sites can enhance archaeological interpretations of site use but can also, more fundamentally, provide an initial indication of contamination risk from such sites. Systematic evaluations of total soil Cu concentrations at ancient metalworking sites have not been conducted, due in part to the limitations of conventional laboratory-based protocols. In this paper, we first review what is known about Cu soil concentrations at ancient metallurgy sites. We then assess the benefits and challenges of portable X-ray fluorescence spectrometry (pXRF) as an alternative, rapid technique for the assessment of background and contaminant levels of Cu in soils. We conclude that pXRF is an effective tool for identifying potential contamination. Finally, we provide an overview of some major considerations beyond total Cu concentrations, such as bioavailability assessments, that will need to be considered at such sites to move toward a complete assessment of environmental and human risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antispasmodic effects of Pycnocycla spinosa seed and aerial part extracts on rat ileum and uterus smooth muscle contractions

Directory of Open Access Journals (Sweden)

2008-08-01

Full Text Available Background and the purpose of study: Hydroalcoholic extract of Pycnocycla spinosa has a relaxant effect on ileum and inhibits castor oil induced diarrhoea in mice. However, effects of P. spinosa seed extracts on ileum and uterus hasn't been investigated.  The aim of this study was to investigate effect of P. spinosa seed and extracts of the aerial part on rat ileum and uterus smooth muscle contraction. Methods: A 70% ethanol extract of seed and aerial parts of P. spinosa was prepared by a percolation method. Uterine horns or ileum were dissected from non-pregnant female Wistar rats (200-230g and cut into longitudinal strips and mounted for isotonic recording under 1g tension in Tyrode's solution. Effects of the extracts were examined on tonic contractions induced by KCl (80mM on both tissues and on phasic spasm induced by oxytocin (0.002iu/ml on the uterus. Results: The aerial part extract inhibited rat ileum contractions induced by 80mM KCl (IC50=42±3.4mg/ml in a concentration dependent manner and it also inhibited rat uterus contraction induced by 80 mM KCl. However, its inhibitory effects were observed with higher concentration of the extract (IC50=420±90mg/ml and at concentration of 1.28mg/ml of the extract in the bath the response was 19±7%.  The aerial part extract (40-640mg/ml also reduced the evoked phasic response of uterus by oxytocin (IC50=71±17.3mg/ml. The seed extract reduced the uterus response to oxytocin in a concentration-dependent manner, and inhibited tissue response completely at 160mg/ml (IC50=27±4mg/ml.  Major conclusion: From this study it was concluded that the seed extract of P. spinosa have similar inhibitory properties on rat isolated uterus and ileum contractions, while the extract of the aerial part of P. spinosa is more selective inhibitor of ileum contraction, and at higher concentrations it also inhibits uterus spasm.

Study on the formation of cubic texture in Ni-7 at.% W alloy substrates by powder metallurgy routes

DEFF Research Database (Denmark)

Zhao, Yue; Suo, HongLi; Zhu, YongHua

2009-01-01

One of the main challenges for coated conductor applications is to produce sharp cubic textured alloy substrates with high strength and low magnetism. In this work, the cubic textured Ni–7 at.% W substrates were prepared from different powder metallurgy ingots by rolling-assisted biaxially textured...... substrate processing. The fabrication processes of cubic texture in the Ni–7 at.% W tapes by two powder metallurgy routes are described in detail. Through the optimized process, full width at half maximum values of 6.7° and 5.0° were obtained, as estimated by X-ray (1 1 1) phi scan and (2 0 0) rocking curve...

Chemistry and metallurgy in the Portuguese Empire

Energy Technology Data Exchange (ETDEWEB)

Habashi, F. [Laval Univ., Sainte-Foy, Quebec City, PQ (Canada)

2000-10-01

The foundation and expansion of the Portuguese Empire is sketched, with emphasis on the development of a new type of ship by Prince Henrique the Navigator (AD 1385-1460), known as the caravel. By virtue of its advanced design, it was capable of sailing the stormy seas at high speeds, and thereby was instrumental in extending Portuguese influence over vast territories in South America, Asia and Africa, extending Portuguese know-how in mining, metallurgy, chemistry and trade along with Christianity. The role played by the University of Coimbra, founded in 1306, and the contribution of the Brazilian Geological Survey, established in 1875, and of the School of Mines in Ouro Preto in Brazil in 1876, in the exploitation of the mineral wealth of the Portuguese colonies is chronicled.

In vitro degradation and cytotoxicity of Mg/Ca composites produced by powder metallurgy.

Science.gov (United States)

Zheng, Y F; Gu, X N; Xi, Y L; Chai, D L

2010-05-01

Mg/Ca (1 wt.%, 5 wt.%, 10 wt.% Ca) composites were prepared from pure magnesium and calcium powders using the powder metallurgy method, aiming to enlarge the addition of Ca content without the formation of Mg(2)Ca. The microstructures, mechanical properties and cytotoxicities of Mg/Ca composite samples were investigated. The corrosion of Mg/Ca composites in Dulbecco's modified Eagle's medium (DMEM) for various immersion intervals was studied by electrochemical impedance spectroscopy measurements and environmental scanning electron microscope, with the concentrations of released Mg and Ca ions in DMEM for various immersion time intervals being measured. It was shown that the main constitutional phases were Mg and Ca, which were uniformly distributed in the Mg matrix. The ultimate tensile strength (UTS) and elongation of experimental composites decreased with increasing Ca content, and the UTS of Mg/1Ca composite was comparable with that of as-extruded Mg-1Ca alloy. The corrosion potential increased with increasing Ca content, whereas the current density and the impedance decreased. It was found that the protective surface film formed quickly at the initial immersion stage. With increasing immersion time, the surface film became compact, and the corrosion rate of Mg/Ca composites slowed down. The surface film consisted mainly of CaCO(3), MgCO(3)x3H(2)O, HA and Mg(OH)(2) after 72 h immersion in DMEM. Mg/1Ca and Mg/5Ca composite extracts had no significant toxicity (p>0.05) to L-929 cells, whereas Mg/10Ca composite extract induced approximately 40% reduced cell viability. Copyright (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Physical metallurgy: Scientific school of the Academician V.M. Schastlivtsev

Science.gov (United States)

Tabatchikova, T. I.

2016-04-01

This paper is to honor Academician Vadim Mikhailovich Schastlivtsev, a prominent scientist in the field of metal physics and materials science. The article comprises an analysis of the topical issues of the physical metallurgy of the early 21st century and of the contribution of V.M. Schastlivtsev and of his school to the science of phase and structural transformations in steels. In 2015, Vadim Mikhailovich celebrates his 80th birthday, and this paper is timed to this honorable date. The list of his main publications is given in it.

Effect of high energy milling time of the aluminum bronze alloy obtained by powder metallurgy with niobium carbide addition

Energy Technology Data Exchange (ETDEWEB)

Dias, Alexandre Nogueira Ottoboni; Silva, Aline da; Rodrigues, Carlos Alberto; Melo, Mirian de Lourdes Noronha Motta; Rodrigues, Geovani; Silva, Gilbert, E-mail: aottoboni@yahoo.com.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil)

2017-05-15

The aluminum bronze alloy is part of a class of highly reliable materials due to high mechanical strength and corrosion resistance being used in the aerospace and shipbuilding industry. It's machined to produce parts and after its use cycle, it's discarded, but third process is considered expensive and besides not being correct for environment reasons. Thus, reusing this material through the powder metallurgy (PM) route is considered advantageous. The aluminum bronze chips were submitted to high energy ball milling process with 3% of niobium carbide (NbC) addition. The NbC is a metal-ceramic composite with a ductile-brittle behaviour. It was analyzed the morphology of powders by scanning electron microscopy as well as particle size it was determined. X ray diffraction identified the phases and the influence of milling time in the diffractogram patterns. Results indicates that milling time and NbC addition improves the milling efficiency significantly and being possible to obtain nanoparticles. (author)

Extract from IAEA's Resources Manual in Nuclear Medicine - Part 2. - Human Resources Development

International Nuclear Information System (INIS)

2003-01-01

The Nuclear Medicine Section of the International Atomic Energy Agency is now engaged in finalizing a reference manual in nuclear medicine, entitled, 'Resources Manual in Nuclear Medicine'. Several renowned professionals from all over the world, from virtually all fields of nuclear medicine have contributed to this manual. The World Journal of Nuclear Medicine will publish a series of extracts from this manual as previews. This is the second extract from the Resources Manual, Part-2 of the chapter on Human Resources Development. (author)

Radiation effects in high-disperse metal media and their application in powder metallurgy

International Nuclear Information System (INIS)

Zaykin, Y.A.; Aliyev, B.A.

2002-01-01

Experimental and theoretical results showing up effects of metal powder radiation processing, such as powder grinding, chemical refinement, and changes in powder particle surface state, are discussed. It is shown that preliminary irradiation of metal powders leads to profound structural alterations at all further stages of their processing by conventional methods of powder metallurgy and eventually effects the properties of the resulting product

Powder metallurgy preparation of Al-Cu-Fe quasicrystals using mechanical alloying and Spark Plasma Sintering

Czech Academy of Sciences Publication Activity Database

Novák, P.; Kubatík, Tomáš František; Vystrčil, J.; Hendrych, R.; Kříž, J.; Mlynár, J.; Vojtěch, D.

2014-01-01

Roč. 52, September (2014), s. 131-137 ISSN 0966-9795 Institutional support: RVO:61389021 Keywords : Nanostructure intermetallics * Ternary alloys systems * Mechanical alloying and milling * Sintering * Diffraction Subject RIV: JG - Metallurgy Impact factor: 2.131, year: 2014 http://www.sciencedirect.com/science/article/pii/S0966979514001198#

Development of new metal matrix composite electrodes for electrical discharge machining through powder metallurgy process

Directory of Open Access Journals (Sweden)

C. Mathalai Sundaram

2014-12-01

Full Text Available Electrical discharge machining (EDM is one of the widely used nontraditional machining methods to produce die cavities by the erosive effect of electrical discharges. This method is popular due to the fact that a relatively soft electrically conductive tool electrode can machine hard work piece. Copper electrode is normally used for machining process. Electrode wear rate is the major drawback for EDM researchers. This research focus on fabrication of metal matrix composite (MMC electrode by mixing copper powder with titanium carbide (TiC and Tungsten carbide (WC powder through powder metallurgy process, Copper powder is the major amount of mixing proportion with TiC and WC. However, this paper focus on the early stage of the project where powder metallurgy route was used to determine suitable mixing time, compaction pressure and sintering and compacting process in producing EDM electrode. The newly prepared composite electrodes in different composition are tested in EDM for OHNS steel.

The stress-corrosion cracking behavior of high-strength aluminum powder metallurgy alloys

Science.gov (United States)

Pickens, J. R.; Christodoulou, L.

1987-01-01

The susceptibility to stress-corrosion cracking (SCC) of rapidly solidified (RS) aluminum powder metallurgy (P/M) alloys 7090 and 7091, mechanically alloyed aluminum P/M alloy IN* 9052, and ingot metallurgy (I/M) alloys of similar compositions was compared using bolt-loaded double cantilever beam specimens. In addition, the effects of aging, grain size, grain boundary segregation, pre-exposure embrittlement, and loading mode on the SCC of 7091 were independently assessed. Finally, the data generated were used to elucidate the mechanisms of SCC in the three P/M alloys. The IN 9052 had the lowest SCC susceptibility of all alloys tested in the peak-strength condition, although no SCC was observed in the two RS alloys in the overaged condition. The susceptibility of the RS alloys was greater in the underaged than the peak-aged temper. We detected no significant differences in susceptibility of 7091 with grain sizes varying from 2 to 300 μm. Most of the crack advance during SCC of 7091 was by hydrogen embrittlement (HE). Furthermore, both RS alloys were found to be susceptible to preexposure embrittlement—also indicative of HE. The P/M alloys were less susceptible to SCC than the I/M alloys in all but one test.

Annals of SAM meeting `96. National meeting on precious metals; Anales de las jornadas SAM `96. Encuentro nacional de metales preciosos

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

Works are presented at the SAM meeting `96 of the Argentine Materials Association. The papers can be grouped under the following main topics: physical metallurgy; ceramics; polymers; precious metals; extractive metallurgy; corrosion; powder metallurgy. refs., ills.

Annals of SAM meeting '96. National meeting on precious metals

International Nuclear Information System (INIS)

1996-01-01

Works are presented at the SAM meeting '96 of the Argentine Materials Association. The papers can be grouped under the following main topics: physical metallurgy; ceramics; polymers; precious metals; extractive metallurgy; corrosion; powder metallurgy. refs., ills

Impact of historical mining assessed in soils by kinetic extraction and lead isotopic ratios

International Nuclear Information System (INIS)

Camizuli, E.; Monna, F.; Bermond, A.; Manouchehri, N.; Besançon, S.; Losno, R.; Oort, F. van; Labanowski, J.; Perreira, A.; Chateau, C.; Alibert, P.

2014-01-01

The aim of this study is to estimate the long-term behaviour of trace metals, in two soils differently impacted by past mining. Topsoils from two 1 km 2 zones in the forested Morvan massif (France) were sampled to assess the spatial distribution of Cd, Cu, Pb and Zn. The first zone had been contaminated by historical mining. As expected, it exhibits higher trace-metal levels and greater spatial heterogeneity than the second non-contaminated zone, supposed to represent the local background. One soil profile from each zone was investigated in detail to estimate metal behaviour, and hence, bioavailability. Kinetic extractions were performed using EDTA on three samples: the A horizon from both soil profiles and the B horizon from the contaminated soil. For all three samples, kinetic extractions can be modelled by two first-order reactions. Similar kinetic behaviour was observed for all metals, but more metal was extracted from the contaminated A horizon than from the B horizon. More surprising is the general predominance of the residual fraction over the “labile” and “less labile” pools. Past anthropogenic inputs may have percolated over time through the soil profiles because of acidic pH conditions. Stable organo-metallic complexes may also have been formed over time, reducing metal availability. These processes are not mutually exclusive. After kinetic extraction, the lead isotopic compositions of the samples exhibited different signatures, related to contamination history and intrinsic soil parameters. However, no variation in lead signature was observed during the extraction experiment, demonstrating that the “labile” and “less labile” lead pools do not differ in terms of origin. Even if trace metals resulting from past mining and metallurgy persist in soils long after these activities have ceased, kinetic extractions suggest that metals, at least for these particular forest soils, do not represent a threat for biota. - Highlights: • Trace

Impact of historical mining assessed in soils by kinetic extraction and lead isotopic ratios

Energy Technology Data Exchange (ETDEWEB)

Camizuli, E., E-mail: estelle.camizuli@u-bourgogne.fr [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Monna, F. [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Bermond, A.; Manouchehri, N.; Besançon, S. [Institut des sciences et industries du vivant et de l' environnement (AgroParisTech), Laboratoire de Chimie Analytique, 16, rue Claude Bernard, 75231 Paris Cedex 05 (France); Losno, R. [UMR 7583, LISA, Universités Paris 7-Paris 12 — CNRS, 61 av. du Gal de Gaulle, 94010 Créteil Cedex (France); Oort, F. van [UR 251, Pessac, Institut National de la Recherche Agronomique, Centre de Versailles-Grignon, RD 10, 78026 Versailles Cedex (France); Labanowski, J. [UMR 7285, IC2MP, Université de Poitiers — CNRS, 4, rue Michel Brunet, 86022 Poitiers (France); Perreira, A. [UMR 6298, ArTeHiS, Université de Bourgogne — CNRS — Culture, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Chateau, C. [UFR SVTE, Université de Bourgogne, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France); Alibert, P. [UMR 6282, Biogeosciences, Université de Bourgogne — CNRS, 6 bd Gabriel, Bat. Gabriel, 21000 Dijon (France)

2014-02-01

The aim of this study is to estimate the long-term behaviour of trace metals, in two soils differently impacted by past mining. Topsoils from two 1 km{sup 2} zones in the forested Morvan massif (France) were sampled to assess the spatial distribution of Cd, Cu, Pb and Zn. The first zone had been contaminated by historical mining. As expected, it exhibits higher trace-metal levels and greater spatial heterogeneity than the second non-contaminated zone, supposed to represent the local background. One soil profile from each zone was investigated in detail to estimate metal behaviour, and hence, bioavailability. Kinetic extractions were performed using EDTA on three samples: the A horizon from both soil profiles and the B horizon from the contaminated soil. For all three samples, kinetic extractions can be modelled by two first-order reactions. Similar kinetic behaviour was observed for all metals, but more metal was extracted from the contaminated A horizon than from the B horizon. More surprising is the general predominance of the residual fraction over the “labile” and “less labile” pools. Past anthropogenic inputs may have percolated over time through the soil profiles because of acidic pH conditions. Stable organo-metallic complexes may also have been formed over time, reducing metal availability. These processes are not mutually exclusive. After kinetic extraction, the lead isotopic compositions of the samples exhibited different signatures, related to contamination history and intrinsic soil parameters. However, no variation in lead signature was observed during the extraction experiment, demonstrating that the “labile” and “less labile” lead pools do not differ in terms of origin. Even if trace metals resulting from past mining and metallurgy persist in soils long after these activities have ceased, kinetic extractions suggest that metals, at least for these particular forest soils, do not represent a threat for biota. - Highlights: • Trace

Effect of Water Extract Originated from Different Part of Russian Knapweed (Acroptilon repens L. on Growth of Purslane (Portulaca oleracea L.

Directory of Open Access Journals (Sweden)

Alireza PIRZAD

2012-05-01

Full Text Available To evaluate probable allelopathic effect of water extract originated from different parts of russian knapweed (Acroptilon repens L. on growth of purslane (Portulaca oleracea L., a factorial experiment was conducted based on randomized complete block design with three replications at greenhouse condition in 2011. Treatments were water extract concentrations (0, 5, 10, 15 and 20 percent obtained from different part of russian knapweed (aerial part, flower and root. Results showed the significant effect of extract type on seedling length, and extract concentration on shoot length, root length and seedling length. Interaction effect between extract type and concentration on the ratio of root/shoot length, seedling fresh weight, seedling dry weight and germination percentage was significant, too. Means comparison indicated that the longest root (3.55 cm, shoot (4.65 cm and seedling (8.20 cm were obtained from control treatment, reducing with higher concentration of extract. The longest shoot (6.95 cm belonged to extract originated from russian knapweed flowers. The highest ratio of root/shoot length (0.73, seedling fresh weight (0.61g and seedling dry weight (0.044 g belonged to control treatment. In general, increasing of extract concentration caused in reduction of germination and seedling traits. Meanwhile, extracts of aerial part had more sever reducing effect than root and flower extracts.

Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe.

Science.gov (United States)

Martínez Cortizas, Antonio; López-Merino, Lourdes; Bindler, Richard; Mighall, Tim; Kylander, Malin E

2016-03-01

Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~3500-3200 cal.yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (>2100 cal.yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35-100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~8000 to ~4980 cal.yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g(-1); (206)Pb/(207)Pb 1.204 ± 0.002). A sustained period of low (206)Pb/(207)Pb ratios occurred from ~4980 to ~2470 cal.yr. BP, which can be divided into four phases: Chalcolithic (~4980-3700 cal.yr. BP), (206)Pb/(207)Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~3700-3500 cal.yr. BP), (206)Pb/(207)Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~3500-2800 cal.yr. BP), (206)Pb/(207)Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~2800-2470 cal.yr. BP), (206)Pb/(207)Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, (206)Pb/(207)Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the earliest phases of mining/metallurgy in the area, and reconcile paleo-environmental and

Development of processes for zircaloy chips recycling by electric arc furnace remelting and powder metallurgy; Desenvolvimento de processos de reciclagem de cavacos de zircaloy via refusao em forno eletrico a arco e metalurgia do po

Energy Technology Data Exchange (ETDEWEB)

Pereira, Luiz Alberto Tavares

2014-09-01

PWR reactors employ, as nuclear fuel, UO{sub 2} pellets with Zircaloy clad. In the fabrication of fuel element parts, machining chips from the alloys are generated. As the Zircaloy chips cannot be discarded as ordinary metallic waste, the recycling of this material is important for the Brazilian Nuclear Policy, which targets the reprocess of Zircaloy residues for economic and environmental aspects. This work presents two methods developed in order to recycle Zircaloy chips. In one of the methods, Zircaloy machining chips were refused using an electric-arc furnace to obtain small laboratory ingots. The second one uses powder metallurgy techniques, where the chips were submitted to hydriding process and the resulting material was milled, isostatically pressed and vacuum sintered. The ingots were heat-treated by vacuum annealing. The microstructures resulting from both processing methods were characterized using optical and scanning electron microscopy. Chemical composition, crystal phases and hardness were also determined. The results showed that the composition of recycled Zircaloy comply with the chemical specifications and presented adequate microstructure for nuclear use. The good results of the powder metallurgy method suggest the possibility of producing small parts, like cladding end-caps, using near net shape sintering. (author)

Practical application of solid phase spectrophotometry in analysis of materials and goods of mining and metallurgy

International Nuclear Information System (INIS)

Duan Qunzhang

1999-01-01

The author reviewed recent development and practical application of solid phase spectrophotometry in analysis of materials and goods of mining-metallurgy. Separation and preconcentration and conditions of coloring determination, sensitivity and range of detection, as well as interference of corresponding method are discussed

Metallurgy department progress report for the period 1 January to 31 December 1976

International Nuclear Information System (INIS)

1977-03-01

The activities of the Metallurgy Department at Riso during 1976 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Fuel Elements, and Non-Destructive Testing. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1976 is included

Metallurgy department progress report for the period 1 January to 31 December 1982

International Nuclear Information System (INIS)

1983-07-01

The activities of the Metallurgy Department at Risoe during 1982 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Deveopment, Fuel Elements. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1982 is included. (author)

Metallurgy department progress report for the period 1 January to 31 December 1983

International Nuclear Information System (INIS)

1984-06-01

The activities of the Metallurgy Department at Risoe during 1983 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, and Fuel Elements. Furthermore, a survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1983 is included. (author)

Metallurgy Department progress report for the period 1 January to 31 December 1984

International Nuclear Information System (INIS)

1985-04-01

The activities of the Metallurgy Department at Risoe during 1984 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, and Fuel Elements. A survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1984 is included. (author)

Metallurgy department progress report for the period 1 January to 31 December 1980

International Nuclear Information System (INIS)

1981-07-01

The activities of the Metallurgy Department at Risoe during 1980 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Fuel Elements, Non-Destructive Testing. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1980 is included. (Author)

Metallurgy department progress report for the period 1 January to 31 December 1981

International Nuclear Information System (INIS)

1982-07-01

The activities of the Metallurgy Department at Risoe during 1981 are described. The work is presented in three chapters: General Materials Research, Technology and Materials Development, Fuel Elements. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1981 is included. (author)

Technology study on removal of Ra, U, Mn and F from the acid wastewater of uranium mining and metallurgy

International Nuclear Information System (INIS)

Wu Yongyong; Zhong Pingru; Wang Gaoshan

2014-01-01

The laboratory study for decreasing the concentration of Ra, U, Mn and F ions in acid wastewater of uranium mining and metallurgy was investigated based on lime neutralization-precipitation technology. The technological flowsheet was composed of removing radium by barium chloride, manganese by air aeration and fluorin by aluminum sulfate, and the quality of the disposed effluent could be accorded with the discharge criteria defined by the state, as the neutralization conditions of pH just being 8.5. Furthermore, the lower precipitation pH value can effectively decrease sediment volume, and reduce the subsequent processing pressures. The technological methods were viable and universally applicable for uranium mining and metallurgy wastewater purification. (authors)

Antinociceptive effect of extracts of Marrubium astracanicum Jacq. aerial parts

Directory of Open Access Journals (Sweden)

Niloofar Kahkeshani

2017-01-01

Full Text Available Objective: The genus Marrubium is used for treatment of joint pain, gout, stomach-ache and colic in Iranian Traditional Medicine. Marrubium astracanicum Jacq. (M. astracanicum is a native species in the flora of Iran. The aim of this study was to evaluate the antinociceptive properties of various extracts of aerial parts of M. astracanicum.Materials and Methods: Antinociceptive activities of total hydroalcoholic extract (THE and its n-hexane (non-polar and residual partition (polar fractions were analyzed using formalin test in mice. Morphine (5 mg/kg and normal saline were used as positive and negative controls, respectively.Results: Intraperitoneal administration of THE (50, 100 and 200 mg/kg, non-polar fraction (200 mg/kg and polar fraction (100 and 200 mg/kg, 30 min before formalin injection, caused significant analgesic activity in acute phase (0-5 min after formalin injection of formalin test (p0.05 in comparison with morphine.  In chronic phase (15–60 min after formalin injection, non-polar and polar fractions (50, 100 and 200 mg/kg showed significant analgesic activity (p0.05 in comparison with morphine.Conclusion: Different extracts of M. astracanicum demonstrated antinociceptive activity that support the traditional usage of Marrubium genus for the treatment of arthritis, gout and other inflammatory diseases.

Application of vacuum metallurgy to separate pure metal from mixed metallic particles of crushed waste printed circuit board scraps.

Science.gov (United States)

Zhan, Lu; Xu, Zhenming

2008-10-15

The principle of separating pure metal from mixed metallic particles (MMPs) byvacuum metallurgy is that the vapor pressures of various metals at the same temperature are different As a result, the metal with high vapor pressure and low boiling point can be separated from the mixed metals through distillation or sublimation, and then it can be recycled through condensation under a certain condition. The vacuum metallurgy separation (VMS) of MMPs of crushed waste printed circuit boards (WPCBs) has been studied in this paper. Theoretical analyses show that the MMPs (copper, zinc, bismuth, lead, and indium, for example) can be separated by vacuum metallurgy. The copper particles (0.15-0.20 mm) and zinc particles (<0.30 mm) were chosen to simulate the MMPs of crushed WPCBs. Experimental results show that the separated efficiency of zinc in the copper-rich particles achieves 96.19 wt % when the vacuum pressure is 0.01-0.10 Pa, the heating temperature is 1123 K, and the heating time is 105 min. Under this operation condition, the separated efficiency of zinc in the copper-rich particles from crushed WPCBs achieves 97.00 wt % and the copper purity increases from 90.68 to 99.84 wt %.

[Concomitant influence of occupational and social risk factors on health of workers engaged into powder metallurgy].

Science.gov (United States)

Shur, P Z; Zaĭtseva, N V; Kostarev, V G; Lebedeva-Nesevria, N A; Shliapnikov, D M

2012-01-01

Results of health risk evaluation in workers engaged into powder metallurgy, using complex of hygienic, medical, epidemiologic and sociologic studies, enable to define priority occupational and social risk factors, to assess degree of their influence on the workers' health and to identify occupationally induced diseases.

Leaching of APC residues from secondary Pb metallurgy using single extraction tests: the mineralogical and the geochemical approach.

Science.gov (United States)

Ettler, Vojtech; Mihaljevic, Martin; Sebek, Ondrej; Strnad, Ladislav

2005-05-20

Two air-pollution-control (APC) residues--one from flue gas cooling with alkaline water and one from deionized water cooling--from secondary lead metallurgy were submitted to two different standardized short-term leaching protocols: US EPA toxicity characteristic leaching procedure (TCLP) and static leaching according to Czech/European norm EN 12457-2. The experimental procedure was coupled with detailed mineralogical investigation of the solid material (SEM, XRPD) and speciation-solubility calculations using the PHREEQC-2 geochemical code. Both types of residues were considered as hazardous materials exhibiting substantial leaching of Pb (up to 7130 mg/l) and other inorganic contaminants. However, the APC residue produced by flue gas cooling with alkaline water (sample B) exhibits more favourable leaching and environmental characteristics than that produced by simple deionised water cooling (sample A). At pH 6, phosgenite (PbCl2.PbCO3) became the dominant secondary phase. The results are consistent with the mineralogical and geochemical studies focused on acidic forest soils highly polluted by smelter emissions, where anglesite, as a unique Pb-bearing phase, has been detected. From the technological point of view, the mixing of APC residue with alkaline water, followed by an increase in the suspension pH and equilibration with atmospheric CO2, may be used to ensure the precipitation of less soluble Pb carbonates, which are more easily recycled in the Pb recovery process in the metallurgical plant.

Application of liquid metals for the extraction of solid metals

International Nuclear Information System (INIS)

Borgstedt, H.U.

1996-01-01

Liquid metals dissolve several solid metals in considerable amounts at moderate temperatures. The dissolution processes may be based upon simple physical solubility, formation of intermetallic phases. Even chemical reactions are often observed in which non-metallic elements might be involved. Thus, the capacity to dissolve metals and chemical properties of the liquid metals play a role in these processes. Besides the solubility also chemical properties and thermochemical data are of importance. The dissolution of metals in liquid metals can be applied to separate the solutes from other metals or non-metallic phases. Relatively noble metals can be chemically reduced by the liquid phases. Such solution processes can be applied in the extractive metallurgy, for instance to extract metals from metallic waste. The recycling of metals is of high economical and ecological importance. Examples of possible processes are discussed. (author)

Assessment of heavy metals exposure, noise and thermal safety in the ambiance of a vacuum metallurgy separation system for recycling heavy metals from crushed e-wastes.

Science.gov (United States)

Zhan, Lu; Xu, Zhenming

2014-12-01

Vacuum metallurgy separation (VMS) is a technically feasible method to recover Pb, Cd and other heavy metals from crushed e-wastes. To further determine the environmental impacts and safety of this method, heavy metals exposure, noise and thermal safety in the ambiance of a vacuum metallurgy separation system are evaluated in this article. The mass concentrations of total suspended particulate (TSP) and PM10 are 0.1503 and 0.0973 mg m(-3) near the facilities. The concentrations of Pb, Cd and Sn in TSP samples are 0.0104, 0.1283 and 0.0961 μg m(-3), respectively. Health risk assessments show that the hazard index of Pb is 3.25 × 10(-1) and that of Cd is 1.09 × 10(-1). Carcinogenic risk of Cd through inhalation is 1.08 × 10(-5). The values of the hazard index and risk indicate that Pb and Cd will not cause non-cancerous effects or carcinogenic risk on workers. The noise sources are mainly the mechanical vacuum pump and the water cooling pump. Both of them have the noise levels below 80 dB (A). The thermal safety assessment shows that the temperatures of the vacuum metallurgy separation system surface are all below 303 K after adopting the circulated water cooling and heat insulation measures. This study provides the environmental information of the vacuum metallurgy separation system, which is of assistance to promote the industrialisation of vacuum metallurgy separation for recovering heavy metals from e-wastes. © The Author(s) 2014.

Powder metallurgy: Solid and liquid phase sintering of copper

Science.gov (United States)

Sheldon, Rex; Weiser, Martin W.

1993-01-01

Basic powder metallurgy (P/M) principles and techniques are presented in this laboratory experiment. A copper based system is used since it is relatively easy to work with and is commercially important. In addition to standard solid state sintering, small quantities of low melting metals such as tin, zinc, lead, and aluminum can be added to demonstrate liquid phase sintering and alloy formation. The Taguchi Method of experimental design was used to study the effect of particle size, pressing force, sintering temperature, and sintering time. These parameters can be easily changed to incorporate liquid phase sintering effects and some guidelines for such substitutions are presented. The experiment is typically carried out over a period of three weeks.

Surface metallurgy of cemented carbide tools

International Nuclear Information System (INIS)

Chopra, K.L.; Kashyap, S.C.; Rao, T.V.; Rajagopalan, S.; Srivastava, P.K.

1983-01-01

Transition metal carbides, owing to their high melting point, hardness and wear resistance, are potential candidates for specific application in rockets, nuclear engineering equipment and cutting tools. Tungsten carbide sintered with a binder (either cobalt metal or a mixture of Co + TiC and/or TaC(NbC)) is used for cutting tools. The surface metallurgy of several commercially available cemented carbide tools was studied by Auger electron spectroscopy and X-ray photoelectron spectroscopy techniques. The tool surfaces were contaminated by adsorbed oxygen up to a depth of nearly 0.3 μm causing deterioration of the mechanical properties of the tools. Studies of fractured samples indicated that the tool surfaces were prone to oxygen adsorption. The fracture path passes through the cobalt-rich regions. The ineffectiveness of a worn cutting tool is attributed to the presence of excessive iron from the steel workpiece and carbon and oxygen in the surface layers of the tool. The use of appropriate hard coatings on cemented carbide tools is suggested. (Auth.)

List of unclassified documents by the staff of Metallurgy Division, AERE Harwell from January 1979 to July 1980

International Nuclear Information System (INIS)

Smith, N.C.

1980-12-01

This list constitutes unclassified material published or presented between January 1979 and July 1980, by the staff of Metallurgy Division. It covers reports, memoranda, articles in periodicals, conference papers, books and patent specifications. (author)

Metallurgy department progress report for the period 1 January to 31 December 1978

International Nuclear Information System (INIS)

1979-04-01

The activities of the metallurgy department at Risoe during 1978 are described. The work is presented in four chapters: General materials research, technology and materials development, fuel elements, and non-destructive testing. Furthermore, a survey is given of the depratment's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1978 is included. (author)

Metallurgy Department progress report for the period 1 January to 31 December 1985

International Nuclear Information System (INIS)

Schroeder Pedersen, A.; Bilde Soerensen, J.B.

1986-04-01

The activities of the Metallurgy department at Risoe during 1985 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Chemical and Electrochemical Energy Research and Development, and Fuel elements. A survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1985 is included. (author)

Metallurgy Department progress report for the period 1 January to 31 December 1986

International Nuclear Information System (INIS)

Schroeder Pedersen, A.; Bilde-Soerensen, J.B.

1987-04-01

The activities of the Metallurgy Department at Risoe during 1986 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Chemical and Electrochemical Energy Research and Development, and Fuel Elements. A survey is given of the Department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1986 is included. (editors)

Metallurgy department progress report for the period 1 January to 31 December 1975

International Nuclear Information System (INIS)

1976-03-01

The activities of the Metallurgy Department at Risoe during 1975 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Fuel Elements, and Non-Destructive Testing. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1975 is included. (author)

Metallurgy department progress report for the period 1 January to 31 December 1977

International Nuclear Information System (INIS)

1978-03-01

The activities of the Metallurgy Department at Risoe during 1977 are described. The work is presented in four chapters: General Materials Research, Technology and Materials Development, Fuel elements, and Non-Destructive Testing. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1977 is included. (author)

[Use of powder metallurgy for development of implants of Co-Cr-Mo alloy powder].

Science.gov (United States)

Dabrowski, J R

2001-04-01

This paper discusses the application of powder metallurgy for the development of porous implantation materials. Powders obtained from Co-Cr-Mo alloy with different carbon content by water spraying and grinding, have been investigated. Cold pressing and rotary re-pressing methods were used for compressing the powder. It was found that the sintered materials obtained from water spraying have the most advantageous properties.

Some observations on the physical metallurgy of nickel alloy weld metals

International Nuclear Information System (INIS)

Skillern, C.G.; Lingenfelter, A.C.

1982-01-01

Numerous nickel alloys play critical roles in various energy-related applications. Successful use of these alloys is almost always dependent on the availability of acceptable welding methods and welding products. An understanding of the physical metallurgy of these alloys and their weld metals and the interaction of weld metal and base metal is essential to take full advantage of the useful properties of the alloys. To illustrate this point, this paper presents data for two materials: INCONEL alloy 718 and INCONEL Welding Electrode 132. 8 figures, 9 tables

Experimental Characterization of Aluminum-Based Hybrid Composites Obtained Through Powder Metallurgy

Science.gov (United States)

Marcu, D. F.; Buzatu, M.; Ghica, V. G.; Petrescu, M. I.; Popescu, G.; Niculescu, F.; Iacob, G.

2018-06-01

The paper presents some experimental results concerning fabrication through powder metallurgy (P/M) of aluminum-based hybrid composites - Al/Al2O3/Gr. In order to understand the mechanisms that occur during the P/M processes of obtaining Al/Al2O3/Gr composite, we correlated the physical characteristics with their micro-structural characteristics. The characterization was performed using analysis techniques specific for P/M process, SEM-EDS and XRD analyses. Micro-structural characterization of the composites has revealed fairly uniform distribution this resulting in good properties of the final composite material.

Retraction Note to: Ultra-High Strength and Ductile Lamellar-Structured Powder Metallurgy Binary Ti-Ta Alloys

Science.gov (United States)

Liu, Yong; Xu, Shenghang; Wang, Xin; Li, Kaiyang; Liu, Bin; Wu, Hong; Tang, Huiping

2018-05-01

The editors and authors have retracted the article, "Ultra-High Strength and Ductile Lamellar-Structured Powder Metallurgy Binary Ti-Ta Alloys" by Yong Liu, Shenghang Xu, Xin Wang, Kaiyang Li, Bin Liu, Hong Wu, and Huiping Tang (https://doi.org/10.1007/s11837-015-1801-1).

Antibacterial activities of methanolic extracts of aerial parts of delphinium uncinatum hook's and thoms

International Nuclear Information System (INIS)

Zahoor, M.; Khan, N.

2014-01-01

Methanolic extracts of aerial parts of Delphinium uncinatum Hook's and Thoms were analysed for its antibacterial activities aligned to two gram positive bacterial strains, Bacillus cereus and Staphylococcus aureus and two gram negative bacterial strains, Escherichia coli and Klebsilla pneumonia, using Agar Well Diffusion method. Bactericidal activity was observed against both gram negative and gram positive bacterial strains. Extracts used were more active against Bacillus cereus, Escherichia coli and Staphylococcus aureus at all prepared concentrations but lesser against Klebsilla pneumonia. (author)

Recycling of wastes from uranium mining and metallurgy and recovery of useful resources in China

International Nuclear Information System (INIS)

Pan Yingjie; Xue Jianxin; Chen Zhongqiu

2012-01-01

Recycling of wastes from uranium mining and metallurgy in China and recovery of useful resources are summarized from the aspects such as recovery of uranium from mine water, reusing of waste water, decontaminating and recycling of radioactivity contaminated metal, backfill of gangues and tailings, and comprehensive recovery and utilization of associated uranium deposits. (authors)

8th international congress on mining and metallurgy. 8. Congreso internacional de mineria y metalurgia

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

The meeting covered many aspects of mining and metallurgy including: underground and surface mining of coal; coal preparation; desulfurization and conversion; coal and coal waste combustion, including FBC; coal quality and chemistry; coal gasification; research programs on coal, the economics of the Spanish coal industry; and the Spanish coal industry and the European Community.

High performance Ti-6Al-4V + TiC alloy by blended elemental powder metallurgy

International Nuclear Information System (INIS)

Fujii, H.; Yamazaki, T.; Horiya, T.; Takahashi, K.

1993-01-01

The blended elemental powder metallurgy (BE) of titanium alloys is one of the most cost saving technologies, in which the blending of titanium powder and alloying element powders (or master alloy powders), precise compaction at room temperature, and consolidation are conducted in turn. In addition to some economical and material saving advantages, the BE has a noteworthy feature, that is, the synthesis of special alloy systems which are difficult to be produced by the ingot metallurgy. A particle or fiber reinforced metal matrix composite (MMC) is one of the examples, and the addition of TiC particles to the extensively used Ti-6Al 4V has succeeded in obtaining higher tensile strength, Young's modulus, and elevated temperature properties. However, the raising up of some properties sometimes deteriorates other ones in MMC, and it often prevents the practical use. In this research work, the improvement of tensile ductility and fatigue properties of Ti-6Al-4V+TiC alloys without lowering other mechanical properties is aimed through the microstructural control

Involvement of NFκB in the antirheumatic potential of Chenopodium album L., aerial parts extracts.

Science.gov (United States)

Arora, Sumit K; Itankar, Prakash R; Verma, Prashant R; Bharne, Ashish P; Kokare, Dadasaheb M

2014-08-08

Chenopodium album L. (C. album) is commonly known as Bathua in Hindi (Family: Chenopodiaceae). Traditionally, the plant is used as a laxative, diuretic, sedative and the infusion of the plant is used for the treatment of rheumatism. However, no scientific validation is available on the antirheumatic potential of the plant. In the present investigation, role of NF kappa B (NFκB) in the antiarthritic potential of extracts of aerial parts of Chenopodium album was explored and evaluated. The defatted aerial parts of Chenopodium album were successively extracted with ethylacetate, acetone, methanol and 50% methanol to study their antioxidant capacity followed by antiarthritic potential using Complete Freund׳s adjuvant (CFA) induced arthritis model in rats. The polyphenol, flavonoid and flavanone contents of different extracts were quantified and correlated with their antioxidant capacity, antiarthritic activity and NFκB inhibition potential. The experimental data indicated that the acetone extract of Chenopodium album (ACCA) has shown significant reduction in rat paw edema (80.13%) at dose level of 200 mg/kg per oral in 21 days of this study. On 22nd day, hematological and biochemical parameters were estimated and it was observed that the altered hematological parameters (Hb, RBC, WBC and ESR), biochemical parameters (Serum creatinine, total proteins and acute phase proteins) and loss in body weight in the arthritic rats were significantly brought back to near normal level by the ACCA extract. ACCA extract significantly decreased the NFκB expression in paraventricular nucleus of hypothalamus and this effect is comparable with standard indomethacine in CFA treated rats. The polyphenolic and flavonoid content of different extracts were in the range of 14.56±0.21-42.00±0.2 mg (gallic acid equivalent/g extract) and 2.20±0.003-7.33±0.5 mg (rutin equivalent/g extract) respectively. The antiarthritic activity possessed by ACCA extract can be correlated directly to its

Estimation and characterization of PCDD/Fs, dl-PCBs, PCNs, HxCBz and PeCBz emissions from magnesium metallurgy facilities in China.

Science.gov (United States)

Nie, Zhiqiang; Zheng, Minghui; Liu, Wenbin; Zhang, Bing; Liu, Guorui; Su, Guijin; Lv, Pu; Xiao, Ke

2011-12-01

Magnesium production is considered to be one potential source of unintentional persistent organic pollutants (unintentional POPs). However, studies on the emissions of unintentional POPs from magnesium metallurgy are still lacking. Emissions of unintentional POPs, such as polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), polychlorinated naphthalenes (PCNs), hexachlorobenzene (HxCBz) and pentachlorobenzene (PeCBz) are covered under the Stockholm Convention. In this study, these emissions were investigated through a magnesium smelting process. Stack gas and fly ash samples from a typical magnesium plant in China were collected and analyzed to estimate the emissions of unintentional POPs from magnesium metallurgy. Emissions factors of 412 ng TEQ t(-1) for PCDD/Fs, 18.6 ng TEQ t(-1) for dl-PCBs, 3329 μg t(-1) for PCNs, 820 μg t(-1) for HxCBz, and 1326 μg t(-1) for PeCBz were obtained in 2009. Annual emissions from magnesium metallurgy in China were estimated to be 0.46 g WHO-TEQ for PCDD/Fs and dl-PCBs, 1651 g for PCNs, 403 g for HxCBz and 653 g for PeCBz, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization of aluminum/steel components from recycled swarf using the powder metallurgy as technique

International Nuclear Information System (INIS)

Souza, V.E.S.; Masieiro, F.R.S.; Lourenco, J.M.; Felipe, R.C.T.S.

2009-01-01

Full text: The powder metallurgy process consists to produce metallic or ceramic components through pressure in a powder mass. These components will be submitted to a sintering temperature in order to consolidate them and then improve their mechanical proprieties. The industry is responsible for the swarf generation from different manufacture process. This paper has main goal the reutilization of aluminum and steel swarf using the powder metallurgy as technique. The methodology used in this work consists to compact Al 6060 plus steel SAE 1045 as reinforce material at 250MPa, 400MPa and 600MPa. The composition about these compacted will be 30%, 40%, 50% of steel into aluminum matrix. In this way will be analyze the hardness as function of the compressibility and quantity of steel. The samples will be processed at 500°C during 45 minutes using a resistive furnace in a hydrogen atmosphere. Micrographs of the sintered samples will be obtained by using a Scanning Electron Microscope and Optic Microscope. X-rays diffraction will be also used to characterize the phases found to due diffusivity between the steel and aluminum. (author)

Mechanisms of fatigue crack retardation following single tensile overloads in powder metallurgy aluminum alloys

Science.gov (United States)

Bray, G. H.; Reynolds, A. P.; Starke, E. A., Jr.

1992-01-01

In ingot metallurgy (IM) alloys, the number of delay cycles following a single tensile overload typically increases from a minimum at an intermediate baseline stress intensity range, Delta-K(B), with decreasing Delta-K(B) approaching threshold and increasing Delta-K(B) approaching unstable fracture to produce a characteristic 'U' shaped curve. Two models have been proposed to explain this behavior. One model is based on the interaction between roughness and plasticity-induced closure, while the other model only utilizes plasticity-induced closure. This article examines these models, using experimental results from constant amplitude and single overload fatigue tests performed on two powder metallurgy (PM) aluminum alloys, AL-905XL and AA 8009. The results indicate that the 'U'-shaped curve is primarily due to plasticity-induced closure, and that the plasticity-induced retardation effect is through-thickness in nature, occurring in both the surface and interior regions. However, the retardation effect is greater at the surface, because the increase in plastic strain at the crack tip and overload plastic zone size are larger in the plane-stress surface regions than in the plane-strain interior regions. These results are not entirely consistent with either of the proposed models.

Boride particles in a powder metallurgy superalloy

Energy Technology Data Exchange (ETDEWEB)

Witt, M C; Charles, J A

1985-12-01

Using optical and electron metallography, the composition, morphology, and distribution of M/sub 3/B/sub 2/ borides in as-hipped (hot isostatically pressed) samples of the powder metallurgy superalloy Nimonic AP1 have been determined. Two types of boride are present depending on the HIP temperature. Hipping below the boride solvus results in low-aspect ratio particles, distributed both inter- and intragranularly. Hipping above the boride solvus produces high-aspect ratio particles which are exclusively intergranular. A small difference in both lattice parameter and composition has been measured. Electron energy loss spectroscopy of the particles has confirmed the presence of boron, and laser ion-induced mass analysis has indicated a low carbon level. The higher susceptibility to edge cracking during forging of material hipped above the boride solvus is related to the boride morphology. Studies of the subsequent recrystallization of the forged samples have indicated that necklace formation is neither inhibited nor accelerated by the presence of grain boundary borides. 18 references.

Early atmospheric metal pollution provides evidence for Chalcolithic/Bronze Age mining and metallurgy in Southwestern Europe

Energy Technology Data Exchange (ETDEWEB)

Martínez Cortizas, Antonio, E-mail: antonio.martinez.cortizas@usc.es [Departamento de Edafoloxía e Química Agrícola, Facultade de Bioloxía, Universidade de Santiago de Compostela, Campus Sur s/n, Santiago de Compostela (Spain); López-Merino, Lourdes, E-mail: lourdes.lopez-merino@brunel.ac.uk [Institute of Environment, Health and Societies, Brunel University London, UB8 3PH Uxbridge (United Kingdom); Bindler, Richard, E-mail: richard.bindler@umu.se [Department of Ecology and Environmental Science, Umeå University, Umeå (Sweden); Mighall, Tim, E-mail: t.mighall@abdn.ac.uk [Department of Geography & Environment, School of Geosciences, University of Aberdeen, Elphinstone Road, Aberdeen AB24 3UF (United Kingdom); Kylander, Malin E., E-mail: malin.kylander@geo.su.se [Department of Geological Sciences and the Bolin Centre for Climate Research, Stockholm University, SE-10691, Stockholm (Sweden)

2016-03-01

Although archaeological research suggests that mining/metallurgy already started in the Chalcolithic (3rd millennium BC), the earliest atmospheric metal pollution in SW Europe has thus far been dated to ~ 3500–3200 cal. yr. BP in paleo-environmental archives. A low intensity, non-extensive mining/metallurgy and the lack of appropriately located archives may be responsible for this mismatch. We have analysed the older section (> 2100 cal. yr. BP) of a peat record from La Molina (Asturias, Spain), a mire located in the proximity (35–100 km) of mines which were exploited in the Chalcolithic/Bronze Age, with the aim of assessing evidence of this early mining/metallurgy. Analyses included the determination of C as a proxy for organic matter content, lithogenic elements (Si, Al, Ti) as markers of mineral matter, and trace metals (Cr, Cu, Zn, Pb) and stable Pb isotopes as tracers of atmospheric metal pollution. From ~ 8000 to ~ 4980 cal. yr. BP the Pb composition is similar to that of the underlying sediments (Pb 15 ± 4 μg g{sup −1}; {sup 206}Pb/{sup 207}Pb 1.204 ± 0.002). A sustained period of low {sup 206}Pb/{sup 207}Pb ratios occurred from ~ 4980 to ~ 2470 cal. yr. BP, which can be divided into four phases: Chalcolithic (~ 4980–3700 cal. yr. BP), {sup 206}Pb/{sup 207}Pb ratios decline to 1.175 and Pb/Al ratios increase; Early Bronze Age (~ 3700–3500 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.192 and metal/Al ratios remain stable; Late Bronze Age (~ 3500–2800 cal. yr. BP), {sup 206}Pb/{sup 207}Pb decline to their lowest values (1.167) while Pb/Al and Zn/Al increase; and Early Iron Age (~ 2800–2470 cal. yr. BP), {sup 206}Pb/{sup 207}Pb increase to 1.186, most metal/Al ratios decrease but Zn/Al shows a peak. At the beginning of the Late Iron Age, {sup 206}Pb/{sup 207}Pb ratios and metal enrichments show a rapid return to pre-anthropogenic values. These results provide evidence of regional/local atmospheric metal pollution triggered by the

Stress analyses of pump gears produced by powder metallurgy

Energy Technology Data Exchange (ETDEWEB)

Cetinel, Hakan [Celal Bayar Univ., Mechanical Engineering Dept. (Turkey); Yilmaz, Burak

2013-06-01

In this study, trochoidal type (gerotor) hydraulic pump gears were produced by powder metallurgy (P/M) technique. Several gears with different mechanical properties have been obtained by changing process variables. The tooth contact stresses were calculated analytically under particular operation conditions of the hydraulic pump. The 3D models have been obtained from real gears by using Capability Maturity Model (CMM, 3D scanning) operation and SOLIDWORKS software. Stress analyses were conducted on these 3D models by using ANSYS WORKBENCH software. It was found that the density increases by the increase of sintering duration and mechanical properties were positively affected by the increase of density. Maximum deformation takes place in the region of the outer gear where failure generally occurs with the minimum cross-section area.

Coke briquets for metallurgy based on a thermoreactive binder

Energy Technology Data Exchange (ETDEWEB)

Tjutjunnikov, J.B.; Florinskij, V.N.; Orechov, V.N.; Nefedov, P.J.; Sasmurin, V.I.; Kirenskij, V.N. (Khar' kovskii Inzhenerno-Ehkonomicheskii Institut (USSR))

1992-02-01

Describes a process for production of briquets for metallurgy with binder and coke fines or anthracite. The suggested binder is waste phenol resin from the production of phenol (cumene method). Resin properties are given. Possible reaction mechanisms yielding solidified matter are discussed. The production process requires 10-15% binder and applies charge heating up to 200 C over 30 min. Catalytic amounts of sodium hydroxide or sulfuric acid were also employed. The production process is shown in a flowsheet. Properties of produced briquets are tabulated. The briquets were used in a 8 t/h cupola furnace and their performance was compared to that of KL-1 coke. Performance was found to be comparable; the cost of coke briquets was less than that of heating coke. 2 refs.

Technical progress review of extraction of uranium from fly ash

International Nuclear Information System (INIS)

Gao Renxi; Gao Junning; Wu Qingming; Chen Gang; Wan Hongjin; Zhang Ziyue

2014-01-01

The increasing of fly ash in coal-fired power plants at home and abroad year by year and the potential impacts to the environment attracted media attention. Although the extraction of uranium from the fly ash in coal-fired power plants had optional process from technique aspect and sufficient preliminary researches, but considering the low grade of the uranium in fly ash and particularity of the mineral composition, it is easy to have a high cost of extraction. As a consequence, it is not included in the development plan of uranium mining and metallurgy. The present applications of fly ash are only building materials, building roads and pit valley backfill, the resource utilization rate was low and was still in its early stages of development and application. In view of this, the research advances and the latest development trends of extraction of uranium from fly ash at home and abroad were introduced from the technical aspect, and the beneficial analyzes of the prospect and advices to this industry were given. (authors)

The Preventive and Curative Effects of Fresh Garlic Extract And its Aerial Parts on Fibrosarcoma in Balb/c Mice

Directory of Open Access Journals (Sweden)

M Rafieian-kopaei

2012-05-01

Full Text Available Introduction: Garlic has been demonstrated to have anticancer activity in some studies; however its effect on fibrosarcoma is not evident. This study intends to examine the preventive and curative effects of fresh garlic extract and its aerial parts on the growth of WEHI-164 fibrosarcoma cells in Balb/c mice. Methods: In this preclinical study, 48 female inbred Balb/c mice(6 to 7 weeks old were divided in to 6 groups of 8 each. A single aliquot of WEHI-164 cells(5 × 106 cells/100 μl was injected subcutaneously in the chest of animal. Two weeks before or three weeks after cell injection, 0.2 cc of normal saline or 20 mg/kg extract of garlic or its aerial parts were injected intraperitoneally(IP to the Balb/c mice. The tumors sizes were compared with each other, using ANOVA test. The antioxidant potential and total phenolic compounds of the extracts were also assessed. Results: The mean sizes of tumor growth in groups which received fresh garlic extract or its aerial parts were smaller than that of control group. However this difference was significant on the 21st day only in garlic extract group(p<0.05. The antioxidant power of fresh garlic involved 35.6%, whereas for its aerial parts it was 15.3%. Moreover, the general amount of phenol in fresh garlic was 12.61 mg/g and in its aerial parts was 2.44 mg/g. Conclusion: Garlic consumption might have a crucial role in prevention and control of fibrosarcoma growth. Furthermore, the phenolic compounds and antioxidant activity of garlic aerial parts are less in comparison to garlic itself, however, higher doses might have anticancer activity

Proceedings of the III International Congress of Mining and Metallurgy MINEMETAL 2016

International Nuclear Information System (INIS)

2016-10-01

The III International Congress of Mining and Metallurgy was inaugurated at the Plaza América Convention Center in Varadero. Professionals from 16 countries come together to promote scientific exchange for sustainable mining and to make concrete future investments to boost the development of this important sector in Cuba. Among the topics that will occupy the agenda of these days of congress stand out the development of geology, new technological processes, advances in the application of zeolite, sustainable development and care of the environment.

Powder metallurgy Rene 95 rotating turbine engine parts, volume 2

Science.gov (United States)

Wilbers, L. G.; Redden, T. K.

1981-01-01

A Rene 95 alloy as-HIP high pressure turbine aft shaft in the CF6-50 engine and a HIP plus forged Rene 95 compressor disk in the CFM56 engine were tested. The CF6-50 engine test was conducted for 1000 C cycles and the CFM56 test for 2000 C cycles. Post test evaluation and analysis of the CF6-50 shaft and the CFM56 compressor disk included visual, fluorescent penetrant, and dimensional inspections. No defects or otherwise discrepant conditions were found. These parts were judged to have performed satisfactorily.

Treatment of different parts of corn stover for high yield and lower polydispersity lignin extraction with high-boiling alkaline solvent.

Science.gov (United States)

Yang, Mengyao; Rehman, Muhammad Saif Ur; Yan, Tingxuan; Khan, Asad Ullah; Oleskowicz-Popiel, Piotr; Xu, Xia; Cui, Ping; Xu, Jian

2018-02-01

The influence of different parts of corn stover on lignin extraction was investigated. Five kinds of lignin were isolated by the high boiling point solvent extraction from the whole corn stover and four different parts including leaf, husk, bark and pith. The optimal condition was obtained: 6.25 g/L NaOH, 140 °C, 1 h and 60% (v/v) 1,4-butanediol. The extracted lignins were then characterized. FT-IR analysis revealed that all of the lignins were typically herbaceous. The lignin extracted from husk contained more S unit. Gel permeation chromatography analysis showed that it was necessary to separate corn stover into different parts to obtain low polydispersity lignin. The SEM and FT-IR analysis proved that the lignin dissolution was related to the tightness structure presenting a positive correlation with hydrogen bond index. Copyright © 2017 Elsevier Ltd. All rights reserved.

ITRA 084 - a microprocessor controlled rapid analyzer in mining and metallurgy

International Nuclear Information System (INIS)

Kliem, V.; Kreher, M.; Boy, N.

1986-01-01

A new rapid analyzer of the ITRA series has been developed at the Freiberg Research Institute of Non-Ferrous Metals for single and multi-element analysis in mining and non-ferrous metallurgy. INTRA-08 represents an efficient microprocessor-controlled on-line X-ray fluorescence analyzer based on the main principles utilized with success hitherto in device engineering (isotope excitation, four-channel modification, balance filter method). A U880 single-chip microcomputer provides the central control of the device including the execution of an extensive program for the matrix correction. The efficiency of the analyzer is demonstrated taking measured values as a basis

Porous titanium scaffolds fabricated using a rapid prototyping and powder metallurgy technique.

Science.gov (United States)

Ryan, Garrett E; Pandit, Abhay S; Apatsidis, Dimitrios P

2008-09-01

One of the main issues in orthopaedic implant design is the fabrication of scaffolds that closely mimic the biomechanical properties of the surrounding bone. This research reports on a multi-stage rapid prototyping technique that was successfully developed to produce porous titanium scaffolds with fully interconnected pore networks and reproducible porosity and pore size. The scaffolds' porous characteristics were governed by a sacrificial wax template, fabricated using a commercial 3D-printer. Powder metallurgy processes were employed to generate the titanium scaffolds by filling around the wax template with titanium slurry. In the attempt to optimise the powder metallurgy technique, variations in slurry concentration, compaction pressure and sintering temperature were investigated. By altering the wax design template, pore sizes ranging from 200 to 400 microm were achieved. Scaffolds with porosities of 66.8 +/- 3.6% revealed compression strengths of 104.4+/-22.5 MPa in the axial direction and 23.5 +/- 9.6 MPa in the transverse direction demonstrating their anisotropic nature. Scaffold topography was characterised using scanning electron microscopy and microcomputed tomography. Three-dimensional reconstruction enabled the main architectural parameters such as pore size, interconnecting porosity, level of anisotropy and level of structural disorder to be determined. The titanium scaffolds were compared to their intended designs, as governed by their sacrificial wax templates. Although discrepancies in architectural parameters existed between the intended and the actual scaffolds, overall the results indicate that the porous titanium scaffolds have the properties to be potentially employed in orthopaedic applications.

Proceedings of the international symposium for research scholars on metallurgy, materials science and engineering

International Nuclear Information System (INIS)

2010-01-01

Topics covered in this symposium are: steels, functional materials posters, computational materials science, casting and solidification, polymer matrix composites, posters electronic materials, environmental degradation processing of non-metallic materials posters, energy materials, materials forming technology, biomaterials, magnetic materials, mechanical behaviour of materials posters, phase transformations and physical metallurgy, surface engineering, nanostructured materials, ceramics, processing of metals, materials joining technology and optical materials. Papers relevant to INIS are indexed separately

Determination of total triterpenoid acids in different part and extract of Ganoderma lucidum

Directory of Open Access Journals (Sweden)

FENG Huiqin

2013-04-01

Full Text Available Aim To develop a method for determination of total triterpenoid acids in different part and extracts of Ganoderma lucidum. Method The samples of Ganoderma lucidum were extracted with ethanol and successively extracted with CHCl3 and 5% NaHCO3,the NaHCO3 layer was acidified to pH 3 with 2 mol/L HCl,the resulting precipitates were dissolved in CHCl3 and evaporated in vacuo then weighed. The total triterpenoid acids were obtained. Result The total triterpenoid acids of Ganoderma lucidum fruitbody,spore and mycelium were (8.58±0.25 mg/g,(3.48±0.03 mg/g and (1.75 ±0.09 mg/g respectively. The total triterpenoid acids of pileus and stipe were (12.62±0.22 mg/g and (7.66±0.08 mg/g. The range of total triterpenoid acid content among 10 batches of Ganoderma lucidum fruitbody purchased from the market was between 4.34 to 16.39 mg/g. The highest content fro/8/8/88/ m Ganoderma lucidum fruiting body with alcohol - water extracting was (208.70±5.54 mg/g and the lowest content with alkaline solution extracting was (123.07±4.99 mg/g. The composition of total triterpenoid acid from fruitbody,spores and extract of fruitbody analyzed by HPLC were almost the same. This method is reliable for determination of total triterpenoid acid in the fruiting body and its extracts,spore and mycelium from Ganoderma lucidum,which provides an indicator for the quality of Ganoderma lucidum product.

Recent trends in extractive metallurgy

Directory of Open Access Journals (Sweden)

Habashi F.

2009-01-01

Full Text Available While pyrometallurgical processes are old technology and were the dominant and logical route used to treat sulfide concentrates they are now challenged by new hydrometallurgical processes. In these new processes there have been attempts in the past few years to avoid using autoclaves in the treatment of concentrates of zinc, copper, and nickel. The situation has been recently reversed and pressure hydrometallurgy is being applied in many operations. An outline of these processes is given and the future trend is discussed.

Accelerated Threshold Fatigue Crack Growth Effect-Powder Metallurgy Aluminum Alloy

Science.gov (United States)

Piascik, R. S.; Newman, J. A.

2002-01-01

Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low (Delta) K, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = K(sub min)/K(sub max)). The near threshold accelerated FCG rates are exacerbated by increased levels of K(sub max) (K(sub max) = 0.4 K(sub IC)). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and K(sub max) influenced accelerated crack growth is time and temperature dependent.

The synthesis and characterization of Mg-Zn-Ca alloy by powder metallurgy process

Energy Technology Data Exchange (ETDEWEB)

Annur, Dhyah; Franciska, P.L.; Erryani, Aprilia; Amal, M. Ikhlasul; Kartika, Ika, E-mail: pepeng2000@yahoo.com [Research center for Metallurgy and Material, Indonesian Institute of Science (Indonesia); Sitorus, Lyandra S. [Sultan Ageng Tirtayasa University (Indonesia)

2016-04-19

Known for its biodegradation and biocompatible properties, magnesium alloys have gained many interests to be researched as implant material. In this study, Mg-3Zn-1Ca, Mg-29Zn-1Ca, and Mg-53Zn-4.3Ca (in wt%) were synthesized by means of powder metallurgy method. The compression strength and corrosion resistance of magnesium alloy were thoroughly examined. The microstructures of the alloy were characterized using optical microscopy, Scanning Electron Microscope, and also X-ray diffraction analysis. The corrosion resistance were evaluated using electrochemical analysis. The result indicated that Mg- Zn- Ca alloy could be synthesized using powder metallurgy method. This study showed that Mg-29Zn-1Ca would make the highest mechanical strength up to 159.81 MPa. Strengthening mechanism can be explained by precipitation hardening and grain refinement mechanism. Phase analysis had shown the formation of α Mg, MgO, and intermetallic phases: Mg2Zn11 and also Ca2Mg6Zn3. However, when the composition of Zn reach 53% weight, the mechanical strength will be decreasing. In addition, all of Mg-Zn-Ca alloy studied here had better corrosion resistance (Ecorr around -1.4 VSCE) than previous study of Mg. This study indicated that Mg- 29Zn- 1Ca alloy can be further analyzed to be a biodegradable implant material.

Radiometric measurement techniques in metallurgy and foundry technology

International Nuclear Information System (INIS)

1990-01-01

The contributions contain informations concerning the present state and development of radiometric measurement techniques in metallurgy and foundry technology as well as their application to the solution of various problems. The development of isotope techniques is briefly described. Major applications of radiometric equipment in industrial measurement are presented together with the use of isotopes to monitor processes of industrial production. This is followed by a short description of numerous laboratory-scale applications. Another contribution deals with fundamental problems and methods of moisture measurement by neutrons. A complex moisture/density measurement device the practical applicability of which has been tested is described here. Possibilities for clay determination in used-up moulding materials are discussed in a further contribution. The clay content can be determined by real-time radiometric density measurement so that the necessary moisture or addition of fresh sand can be controlled. (orig.) With 20 figs., 9 tabs., 178 refs [de

Phase Stability of a Powder Metallurgy Disk Superalloy

Science.gov (United States)

Gabb, Timothy P.; Gayda, John; Kantzos, P.; Telesman, Jack; Gang, Anita

2006-01-01

Advanced powder metallurgy superalloy disks in aerospace turbine engines now entering service can be exposed to temperatures approaching 700 C, higher than those previously encountered. They also have higher levels of refractory elements, which can increase mechanical properties at these temperatures but can also encourage phase instabilities during service. Microstructural changes including precipitation of topological close pack phase precipitation and coarsening of existing gamma' precipitates can be slow at these temperatures, yet potentially significant for anticipated disk service times exceeding 1,000 h. The ability to quantify and predict such potential phase instabilities and degradation of capabilities is needed to insure structural integrity and air worthiness of propulsion systems over the full life cycle. A prototypical advanced disk superalloy was subjected to high temperature exposures, and then evaluated. Microstructural changes and corresponding changes in mechanical properties were quantified. The results will be compared to predictions of microstructure modeling software.

Scaleup of powder metallurgy processed Nb-Al multifilamentary wire

International Nuclear Information System (INIS)

Thieme, C.; Foner, S.; Otubo, J.; Pourrahimi, S.; Schwartz, B.; Zhang, H.

1983-01-01

Power metallurgy processed Nb-Al superconducting wires were fabricated from billets up to 45 mm o.d. with nominal areal reduction ratios, R, up to 2 X 10 5 , Nb powder sizes from 40 to 300 μm from various sources, Al powder sizes from 9 to 75 μm, Al concentrations from 3 to 25 wt % Al and with a wide range of heat treatments. All the compacts used tap density powder in a Cu tube and swaging and/or rod rolling and subsequent wire drawing. Both single strand and bundled wires were made. Overall critical current densities, J /SUB c/, of 2 X 10 4 A/cm 2 at 14 T and 10 4 A/cm 2 at 16 T were achieved for 6 to 8 wt % Al in Nb

The shielding against radiation produced by powder metallurgy with tungsten copper alloy applied on transport equipment for radio-pharmaceutical products

International Nuclear Information System (INIS)

Cione, Francisco C.; Sene, Frank F.; Souza, Armando C. de; Betini, Evandro G.; Rossi, Jesualdo L.; Rizzuto, Marcia A.

2015-01-01

Safety is mandatory on medicine radiopharmaceutical transportation and dependent on radiation shielding material. The focus of the present work is to minimize the use of harmful materials as lead and depleted uranium usually used in packages transportation. The tungsten-copper composite obtained by powder metallurgy (PM) is non-toxic. In powder metallurgy the density and the porosity of the compacted parts depends basically upon particle size distribution of each component, mixture, compacting pressure and sintering temperature cycle. The tungsten-copper composite, when used for shielding charged particles, X-rays, gamma photons or other photons of lower energy require proper interpretation of the radiation transport phenomena. The radioactive energy reduction varies according to the porosity and density of the materials used as shielding. The main factor for radiation attenuation is the cross section value for tungsten. The motivation research factor is an optimization of the tungsten and cooper composition in order to achieve the best linear absorption coefficient given by equation I (x) = I 0 e (-ux) . Experiments were conducted to quantify the effective radiation shielding properties of tungsten-copper composite produced by PM, varying the cooper amount in the composite. The studied compositions were 15%, 20% and 25% copper in mass. The Compaction pressure was 270 MPa and the sintering atmosphere was in 1.1 atm in N 2 +H 2 . The sintering temperature was 980 deg C for 2 h. The linear absorption coefficient factor was similar either for the green and the sintered compacts, due the amount of porosity did not affect the radiation attenuation. Thus the sintered was meant for size reduction and mechanical properties enhancement. (author)

The shielding against radiation produced by powder metallurgy with tungsten copper alloy applied on transport equipment for radio-pharmaceutical products

Energy Technology Data Exchange (ETDEWEB)

Cione, Francisco C.; Sene, Frank F.; Souza, Armando C. de; Betini, Evandro G.; Rossi, Jesualdo L., E-mail: fceoni@hotmail.com, E-mail: ffsene@hotmail.com, E-mail: armandocirilo@yahoo.com, E-mail: evandrobetini@gmail.com, E-mail: jelrossi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rizzuto, Marcia A., E-mail: marizzutto@if.usp.br [Universidade de Sao Paulo (IF/USP), SP (Brazil). Instituto de Fisica

2015-07-01

Safety is mandatory on medicine radiopharmaceutical transportation and dependent on radiation shielding material. The focus of the present work is to minimize the use of harmful materials as lead and depleted uranium usually used in packages transportation. The tungsten-copper composite obtained by powder metallurgy (PM) is non-toxic. In powder metallurgy the density and the porosity of the compacted parts depends basically upon particle size distribution of each component, mixture, compacting pressure and sintering temperature cycle. The tungsten-copper composite, when used for shielding charged particles, X-rays, gamma photons or other photons of lower energy require proper interpretation of the radiation transport phenomena. The radioactive energy reduction varies according to the porosity and density of the materials used as shielding. The main factor for radiation attenuation is the cross section value for tungsten. The motivation research factor is an optimization of the tungsten and cooper composition in order to achieve the best linear absorption coefficient given by equation I{sub (x)} = I{sub 0}e{sup (-ux)}. Experiments were conducted to quantify the effective radiation shielding properties of tungsten-copper composite produced by PM, varying the cooper amount in the composite. The studied compositions were 15%, 20% and 25% copper in mass. The Compaction pressure was 270 MPa and the sintering atmosphere was in 1.1 atm in N{sub 2}+H{sub 2}. The sintering temperature was 980 deg C for 2 h. The linear absorption coefficient factor was similar either for the green and the sintered compacts, due the amount of porosity did not affect the radiation attenuation. Thus the sintered was meant for size reduction and mechanical properties enhancement. (author)

Phytochemical screening and in vitro bioactivities of the extracts of aerial part of Boerhavia diffusa Linn.

Science.gov (United States)

Apu, Apurba Sarker; Liza, Mahmuda Sultana; Jamaluddin, A T M; Howlader, Md Amran; Saha, Repon Kumer; Rizwan, Farhana; Nasrin, Nishat

2012-09-01

To investigate the bioactivities of crude n-hexane, ethyl acetate and methanol extracts of aerial part of Boerhavia diffusa Linn. (B. diffusa) and its phytochemical analysis. The identification of phytoconstituents and assay of antioxidant, thrombolytic, cytotoxic, antimicrobial activities were conducted using specific standard in vitro procedures. The results showed that the plant extracts were a rich source of phytoconstituents. Methanol extract showed higher antioxidant, thrombolytic activity and less cytotoxic activity than those of n-hexane and ethyl acetate extracts of B. diffusa. Among the bioactivities, antioxidant activity was the most notable compared to the positive control and thus could be a potential rich source of natural antioxidant. In case of antimicrobial screening, crude extracts of the plant showed remarkable antibacterial activity against tested microorganisms. All the extracts showed significant inhibitory activity against Candida albicuns, at a concentration of 1000 µg/disc. The present findings suggest that, the plant widely available in Bangladesh, could be a prominent source of medicinally important natural compounds.

X-ray computed microtomography studies of MIM and DPR parts

CSIR Research Space (South Africa)

Muchavi, Noluntu S

2016-10-01

Full Text Available the wider or longer strips into small sections, thus requiring a large number of scans. AcknowledgementsS The contributions of Ntate Sam Papo, Mandy Seerane, Hilda Chikwanda and Pierre Rossouw are duly recognized. This work is funded by the DST and the CSIR... Metal injection moulding (MIM) is a novel process, which combines the advantages of powder metallurgy (PM) and plastic injection moulding. MIM has found widespread applications in the cost-effective production of high-sintered density small parts...

Review of some past and present powder metallurgy programs at the Los Alamos Scientific Laboratory

International Nuclear Information System (INIS)

Sheinberg, H.

1977-01-01

Powder metallurgy programs at LASL are reviewed. Topics covered include: KIWI reactor fuel elements; Phoebus reactor fuel elements, criticality control and poison plate material, structural composites for fuel element supports, and heat shields for fuel element supports; thermionic emitter reactor uranium carbide--zirconium carbide fuel pins, and molybdenum--uranium oxide fuel pins; laser and electron beam fusion targets; and current work in MHD components

Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces; La metalurgia del mercurio en Almaden: desde los hornos de aludeles a los hornos Pacific

Energy Technology Data Exchange (ETDEWEB)

Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

2014-07-01

This paper shows the different types of furnaces for roasting cinnabar, used in the metallurgy of quicksilver over the centuries of exploitation of the Almaden Mines (Spain). Some of these techniques are part of our industrial heritage. They have contributed to name UNESCO World Heritage Site the vast technological legacy of these mines recently. This research contributes to close the long way of metallurgical activity from aludel furnaces until Pacif furnaces, first and lasted technology to produce on an industrial scale. It is delved into the most relevant aspects having to do with the type, evolution and number of furnaces existing on each of the periods. (Author)

Characterization of Powder Metallurgy Processed Pure Magnesium Materials for Biomedical Applications

Directory of Open Access Journals (Sweden)

Matěj Březina

2017-10-01

Full Text Available Magnesium with its mechanical properties and nontoxicity is predetermined as a material for biomedical applications; however, its high reactivity is a limiting factor for its usage. Powder metallurgy is one of the promising methods for the enhancement of material mechanical properties and, due to the introduced plastic deformation, can also have a positive influence on corrosion resistance. Pure magnesium samples were prepared via powder metallurgy. Compacting pressures from 100 MPa to 500 MPa were used for samples’ preparation at room temperature and elevated temperatures. The microstructure of the obtained compacts was analyzed in terms of microscopy. The three-point bendisng test and microhardness testing were adopted to define the compacts’ mechanical properties, discussing the results with respect to fractographic analysis. Electrochemical corrosion properties analyzed with electrochemical impedance spectroscopy carried out in HBSS (Hank’s Balanced Salt Solution and enriched HBSS were correlated with the metallographic analysis of the corrosion process. Cold compacted materials were very brittle with low strength (up to 50 MPa and microhardness (up to 50 HV (load: 0.025 kg and degraded rapidly in both solutions. Hot pressed materials yielded much higher strength (up to 250 MPa and microhardness (up to 65 HV (load: 0.025 kg, and the electrochemical characteristics were significantly better when compared to the cold compacted samples. Temperatures of 300 °C and 400 °C and high compacting pressures from 300 MPa to 500 MPa had a positive influence on material bonding, mechanical and electrochemical properties. A compacting temperature of 500 °C had a detrimental effect on material compaction when using pressure above 200 MPa.

Evaluation of anti-arthritic potential of the methanolic extract of the aerial parts of Costus speciosus

Directory of Open Access Journals (Sweden)

Shruti Srivastava

2012-01-01

Full Text Available Objective : Costus speciosus Koen. (Keu, Crape ginger, an ornamental plant, widely distributed in India is traditionally used as astringent, aphrodisiac, purgative, anthelmintic, depurative, febrifuge and expectorant. The plant is also used in rheumatism, dropsy, urinary diseases and jaundice. The purpose of this study is to evaluate the anti-arthritic activity of the methanolic extract of the aerial parts of Costus speciosus (CS in experimental animal models. Materials and Methods: The powdered drug was subjected to successive solvent extraction, with solvents in increasing order of polarity to obtain the methanolic extract of the aerial parts of the plant. CS was evaluated for anti-arthritic action by Freund′s adjuvant induced arthritis test in adult Albino rats (150-200 gm. Rats were injected 0.1 ml of complete Freund′s adjuvant into the planter region of the left hind paw. Statistical analysis was performed using One way analysis of variance (ANOVA followed by Bonferonni test. P<0.05 was considered statistically significant. Results : The methanolic extract of CS in doses of 400 and 800 mg/kg showed 75.50% and 68.33% protection against increase in paw edema, respectively. CS showed dose-dependent action in all the experimental models. Conclusion : The present study indicates that CS has significant anti-arthritic properties.

Tribological properties of PM212: A high-temperature, self-lubricating, powder metallurgy composite

Science.gov (United States)

Dellacorte, Christopher; Sliney, Harold E.

1989-01-01

This paper describes a research program to develop and evaluate a new high temperature, self-lubricating powder metallurgy composite, PM212. PM212 has the same composition as the plasma-sprayed coating, PS212, which contains 70 wt percent metal-bonded chromium carbide, 15 wt percent silver and 15 wt percent barium fluoride/calcium fluoride eutectic. The carbide acts as a wear resistant matrix and the silver and fluorides act as low and high temperature lubricants, respectively. The material is prepared by sequential cold press, cold isostatic pressing and sintering techniques. In this study, hemispherically tipped wear pins of PM212 were prepared and slid against superalloy disks at temperatures from 25 to 850 C in air in a pin-on-disk tribometer. Friction coefficients range from 0.29 to 0.38 and the wear of both the composite pins and superalloy disks was moderate to low in the 10(exp -5) to 10(exp -6) cubic mm/N-m range. Preliminary tests indicate that the material has a compressive strength of at least 130 MPa over the entire temperature range of 25 to 900 C. This material has promise for use as seal inserts, bushings, small inside diameter parts and other applications where plasma-sprayed coatings are impractical or too costly.

Tribological properties of PM212 - A high temperature, self-lubricating, powder metallurgy composite

Science.gov (United States)

Dellacorte, Christopher; Sliney, Harold E.

1990-01-01

This paper describes a research program to develop and evaluate a new high temperature, self-lubricating powder metallurgy composite, PM212. PM212 has the same composition as the plasma-sprayed coating, PS212, which contains 70 wt percent metal-bonded chromium carbide, 15 wt percent silver and 15 wt percent barium fluoride/calcium fluoride eutectic. The carbide acts as a wear resistant matrix and the silver and fluorides act as low and high temperature lubricants, respectively. The material is prepared by sequential cold press, cold isostatic pressing and sintering techniques. In this study, hemispherically tipped wear pins of PM212 were prepared and slid against superalloy disks at temperatures from 25 to 850 C in air in a pin-on-disk tribometer. Friction coefficients range from 0.29 to 0.38 and the wear of both the composite pins and superalloy disks was moderate to low in the 10(exp -5) to 10(exp -6) cubic mm/N-m range. Preliminary tests indicate that the material has a compressive strength of at least 130 MPa over the entire temperature range of 25 to 900 C. This material has promise for use as seal inserts, bushings, small inside diameter parts and other applications where plasma-sprayed coatings are impractical or too costly.

Recent applications of PIXE spectrometry in archaeology. Pt. 1; Observations on the early development of copper metallurgy in the Old World

Energy Technology Data Exchange (ETDEWEB)

Fleming, S J [MASCA, Univ. Museum, Univ. Pennsylvania, Philadelphia, PA (United States); Swann, C P [Bartol Research Inst., Univ. Delaware, Newark, DE (United States)

1993-04-01

The early development of copper metallurgy can be characterized by three steps of innovation: (i) Exploitation of native copper resources for simple tool-making as early as the 7th millennium B.C. in the Near East; (ii) the recovery of copper metal from minerals such as malachite, by smelting, during the 5th millennium B.C., both in the Near East and in eastern Europe; and (iii) the deliberate alloying of copper and tin, to make bronze, circa 2800 B.C. in Mesopotamia (modern Iraq). This paper reviews the technological aspects associated the first two of these steps, comparing compositional patterns (as determined by PIXE spectrometry) for the copper metallurgy of various regions including the Middle Danube basin, the Tigris basin, and the Iranian Plateau. (orig.).

Spray forming and mechanical properties of a new type powder metallurgy superalloy

International Nuclear Information System (INIS)

Jia Chong-Lin; Ge Chang-Chun; Xia Min; Gu Tian-Fu

2015-01-01

The deposited billet of a new type powder metallurgy (PM) superalloy FGH4095M for use in turbine disk manufacturing has been fabricated using spray forming technology. The metallurgical quality of the deposited billet was analyzed in terms of density, texture, and grain size. Comparative research was done on the microstructure and mechanical properties between the flat disk preform prepared with hot isostatic pressing (HIP) and the same alloy forgings prepared with HIP followed by isothermal forging (IF). The results show that the density of the spray-formed and nitrogen-atomized deposit billet is above 99% of the theoretical density, indicating a compact structure. The grains are uniform and fine. The billet has weak texture with a random distribution in the spray deposition direction and perpendicular to the direction of deposition. A part of atomizing nitrogen exists in the preform in the form of carbonitride. Nitrogen-induced microporosity causes the density reduction of the preform. Compared with the process of HIP+IF, the superalloy FGH4095M after HIP has better mechanical properties at both room temperature and high temperature. The sizes of the γ′ phase are finer in microstructure of the preform after HIP in comparison with the forgings after HIP+IF. This work shows that SF+HIP is a viable processing route for FGH4095M as a turbine-disk material. (paper)

Metallurgy department progress report for the period 1 January to 31 December 1979

International Nuclear Information System (INIS)

1980-07-01

The activities of the Metallurgy Department at Risoe during 1979 are described. The work is presented in four chapters: General material research, technology and materials development, fuel elements, non-destructive testing. An article on wingblades of glass fibre reinforced polyester for a 630 kW windturbine is also included. Furthermore, a survey is given of the department's participation in international collaboration and of its activities within education and training. A list (with abstracts) of publications and lectures by the staff during 1979 is included. (author)

Problem concerning the use of secondary fuel energy systems in ferrous metallurgy

Energy Technology Data Exchange (ETDEWEB)

Shchelokov, Ia M

1981-01-01

Ferrous metallurgy makes available significant amount of secondary fuel energy resources: the possible output of secondary energy resources amounts to about 400 to 450 million gigajoules, the capacity of using secondary energy resources amount to 140 to 150 million gigajoules. Eighty percent of the general amount of the used secondary fuel energy resources is used in mills of open-hearth, rolling, and aneealing production. In the last twenty-five years and in connection with the change in the technological plans in the metallurgical industry, the specific output of secondary energy resources by branch decreased from 4.5 to 2.25 gigajoules per one ton of steel. The designs of mass produced boiler users does not correspond to the technical needs of the developing technology of smelting and annealing production. The Uralenergochermet together with the Ural branch of the F. Dzerzhinski All-Union Heat Engineering Institute, in 1970, introduced into use at the Orsko-Knalilov metallurgical plant, an impulse purification boiler user system. Note is made of the positive test of the operation of the Seversk pipe plant in respect to the dispersion and burning of the grease and fuel oil by products hydrated up to 30 to 40% by using the heat in the boiler users. In a number of Ural metallurgy plants, a 100% use of secondary energy resources in the course of the year was insured. Excellent results were obtained concerning the insurance of the stable operation of the system of the used thermal energy center at the Magnezit Satkin plant.

Assessment of Low Cycle Fatigue Behavior of Powder Metallurgy Alloy U720

Science.gov (United States)

Gabb, Tomothy P.; Bonacuse, Peter J.; Ghosn, Louis J.; Sweeney, Joseph W.; Chatterjee, Amit; Green, Kenneth A.

2000-01-01

The fatigue lives of modem powder metallurgy disk alloys are influenced by variabilities in alloy microstructure and mechanical properties. These properties can vary as functions of variables the different steps of materials/component processing: powder atomization, consolidation, extrusion, forging, heat treating, and machining. It is important to understand the relationship between the statistical variations in life and these variables, as well as the change in life distribution due to changes in fatigue loading conditions. The objective of this study was to investigate these relationships in a nickel-base disk superalloy, U720, produced using powder metallurgy processing. Multiple strain-controlled fatigue tests were performed at 538 C (1000 F) at limited sets of test conditions. Analyses were performed to: (1) assess variations of microstructure, mechanical properties, and LCF failure initiation sites as functions of disk processing and loading conditions; and (2) compare mean and minimum fatigue life predictions using different approaches for modeling the data from assorted test conditions. Significant variations in life were observed as functions of the disk processing variables evaluated. However, the lives of all specimens could still be combined and modeled together. The failure initiation sites for tests performed at a strain ratio R(sub epsilon) = epsilon(sub min)/epsilon(sub max) of 0 were different from those in tests at a strain ratio of -1. An approach could still be applied to account for the differences in mean and maximum stresses and strains. This allowed the data in tests of various conditions to be combined for more robust statistical estimates of mean and minimum lives.

Device for preparing combinatorial libraries in powder metallurgy.

Science.gov (United States)

Yang, Shoufeng; Evans, Julian R G

2004-01-01

This paper describes a powder-metering, -mixing, and -dispensing mechanism that can be used as a method for producing large numbers of samples for metallurgical evaluation or electrical or mechanical testing from multicomponent metal and cermet powder systems. It is designed to make use of the same commercial powders that are used in powder metallurgy and, therefore, to produce samples that are faithful to the microstructure of finished products. The particle assemblies produced by the device could be consolidated by die pressing, isostatic pressing, laser sintering, or direct melting. The powder metering valve provides both on/off and flow rate control of dry powders in open capillaries using acoustic vibration. The valve is simple and involves no relative movement, avoiding seizure with fine powders. An orchestra of such valves can be arranged on a building platform to prepare multicomponent combinatorial libraries. As with many combinatorial devices, identification and evaluation of sources of mixing error as a function of sample size is mandatory. Such an analysis is presented.

An application of powder metallurgy for the LHC

CERN Document Server

Sgobba, Stefano

2004-01-01

The cold mass of the 1232 superconducting dipole magnets of LHC, operating at 1.9 K, is enclosed by a shrinking cylinder and two end covers at its extremities. The covers are structural components that must retain high strength and toughness at cryogenic temperature. They are manufactured by Metso Oy /FI in AISI 316 LN steel by Powder Metallurgy (PM) and Hot Isostatic Pressing. PM represents an attractive near net shaping technique for these components of complex geometry for which dimension tolerances, dimensional stability, weldability are key issues for magnet fabrication, and mechanical properties, ductility and leak tightness have to be guaranteed during operation. The material of the covers and its welds have been fully characterized and mechanically tested down to 4.2 K at CERN. The fine grained structure, the absence of residual stresses, the full isotropy of mechanical properties associated to the low level of Prior Particle Boundaries oxides result in superior mechanical properties and high ductilit...

Investigation of a thermoplastic-powder metallurgy process for the fabrication of porous niobium rods

International Nuclear Information System (INIS)

Nordin, D.R.

1978-06-01

The feasibility of using a thermoplastic-powder metallurgy technique for the fabrication of porous niobium rods was investigated. Some early problems were overcome to successfully extrude the polymer coated niobium powder into long lengths. The effects of certain process variables were investigated. Residual porosity and extrusion pressure were found to be regulated by the polymer fraction. The procedures for taking the extruded polystyrene--niobium rods through the heat treatments to the final, tin infiltrated stage are explained

Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy

OpenAIRE

Ferreira, Sonia C.; Conde, Ana; Arenas, Mar?a A.; Rocha, Luis A.; Velhinho, Alexandre

2014-01-01

Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodi...

Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

Science.gov (United States)

Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

2016-10-01

With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

Emission of PCDD/Fs and dioxin-like PCBs from metallurgy industries in S. Korea.

Science.gov (United States)

Yu, Byeong-Woon; Jin, Guang-Zhu; Moon, Young-Hoon; Kim, Min-Kwan; Kyoung, Jong-Dai; Chang, Yoon-Seok

2006-01-01

The metallurgy industry and municipal waste incinerators are considered the main sources of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/Fs) in many countries. This study investigated the emission factors and total emissions of PCDD/Fs and dioxin-like polychlorinated biphenyls (PCBs) emitted from metallurgy industries (including ferrous and nonferrous foundries) in Korea. The toxic equivalency (TEQ) emission factor of PCDD/Fs was the highest for secondary copper production, at 24451 ng I-TEQ/ton. The total estimated emissions of PCDD/Fs from these sources were 35.259 g I-TEQ/yr, comprising 0.088 g I-TEQ/yr from ferrous foundries, 31.713 g I-TEQ/yr from copper production, 1.716 g I-TEQ/yr from lead production, 0.111 g I-TEQ/yr from zinc production, and 1.631 g I-TEQ/yr from aluminum production. The total estimated annual amounts of dioxin-like PCBs emitted from these sources were 13.260 g WHO-TEQ/yr, comprising 0.014 g WHO-TEQ/yr from ferrous foundries, 12.675 g WHO-TEQ/yr from copper production, 0.170 g WHO-TEQ/yr from lead production, 0.017 g WHO-TEQ/yr from zinc production, and 0.384 g WHO-TEQ/yr from aluminum production. The highest emission factor was found for secondary copper smelting, at 9770 ng WHO-TEQ/ton.

Abnormal flow behavior and necklace microstructure of powder metallurgy superalloys with previous particle boundaries (PPBs)

Energy Technology Data Exchange (ETDEWEB)

Ning, Yongquan, E-mail: luckyning@nwpu.edu.cn [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Zhou, Cong; Liang, Houquan [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 (China); Fu, M.W., E-mail: mmmwfu@polyu.edu.hk [Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (China)

2016-01-15

Powder metallurgy (P/M) has been introduced as an innovative process to manufacture high performance components with fine, homogenous and segregation-free microstructure. Unfortunately, previous particle boundary (PPB) precipitated during the powder metallurgy process. Since undesirable PPB is detrimental to mechanical properties, hot extrusion or/and isothermal forging are needed. In present research, isothermal compression tests were conducted on P/M FGH4096 superalloys with typical PPBs. Abnormal flow behavior during high-speed deformation has been quantitatively investigated. Caused by the competition mechanism between work-hardening and dynamic-softening, abnormal flow behaves typical four stages (viz., work-hardening, stable, softening and steady). Microstructure observation for hardening or/and softening mechanism has been investigated. Meanwhile, necklace microstructure was observed by scanning electron microscope, and the grain fraction analysis was performed by using electron backscatter diffraction. Transmission electron microscopy was used for characterizing the boundary structure. Necklace microstructural mechanism for processing P/M superalloys has been developed, and the dynamic recrystallization model has also been conducted. Bulge–corrugation model is the primary nucleation mechanism for P/M superalloys with PPBs. When PPB is entirely covered with new grains, necklace microstructure has formed. Bulge–corrugation mechanism can repeatedly take place in the following necklace DRX.

Current state of using radionuclides in mining and in metallurgy in the GDR

International Nuclear Information System (INIS)

Holzhey, J.

1987-01-01

Data is presented characterizing the range of the industrial use of tracer and radiometric methods in mining and metallurgy in the GDR in the years 1957-1975 and 1985. Of radiometric methods the most widely used were level gages, densimeters and fire detectors. Level gages were most widely used for measuring the height of filling of hoppers and silos. Radionuclide analytical methods are mainly used in the potassium industry for determining the content of potassium oxide. Natural radiation of 40 K radionuclides is used in the process. (Z.S.). 4 tabs., 2 refs

Anticancer Properties and Phenolic Contents of Sequentially Prepared Extracts from Different Parts of Selected Medicinal Plants Indigenous to Malaysia

Directory of Open Access Journals (Sweden)

Hadiza Altine Adamu

2012-05-01

Full Text Available Different parts of four edible medicinal plants (Casearia capitellata, Baccaurea motleyana, Phyllanthus pulcher and Strobilanthus crispus, indigenous to Malaysia, were extracted in different solvents, sequentially. The obtained 28 extracts were evaluated for their in vitro anticancer properties, using the MTS assay, on four human cancer cell lines: colon (HT-29, breast (MCF-7, prostate (DU-145 and lung (H460 cancers. The best anticancer activity was observed for the ethyl acetate (EA extract of Casearia capitellata leaves on MCF-7 cell lines with IC₅₀ 2.0 μg/mL and its methanolic (MeOH extract showed an outstanding activity against lung cancer cell lines. Dichloromethane (DCM extract of Phyllanthus pulcher aerial parts showed the highest anticancer activity against DU-145 cell lines, while significant activity was exhibited by DCM extract of Phyllanthus pulcher roots on colon cancer cell lines with IC₅₀ value of 8.1 μg/mL. Total phenolic content (TPC ranged over 1–40 mg gallic acid equivalents (GAE/g. For all the samples, highest yields of phenolics were obtained for MeOH extracts. Among all the extracts analyzed, the MeOH extracts of Strobilanthus crispus leaves exhibited the highest TPC than other samples (p < 0.05. This study shows that the nature of phenol determines its anticaner activity and not the number of phenols present.

Metals for bone implants. Part 1. Powder metallurgy and implant rendering.

Science.gov (United States)

Andani, Mohsen Taheri; Shayesteh Moghaddam, Narges; Haberland, Christoph; Dean, David; Miller, Michael J; Elahinia, Mohammad

2014-10-01

New metal alloys and metal fabrication strategies are likely to benefit future skeletal implant strategies. These metals and fabrication strategies were looked at from the point of view of standard-of-care implants for the mandible. These implants are used as part of the treatment for segmental resection due to oropharyngeal cancer, injury or correction of deformity due to pathology or congenital defect. The focus of this two-part review is the issues associated with the failure of existing mandibular implants that are due to mismatched material properties. Potential directions for future research are also studied. To mitigate these issues, the use of low-stiffness metallic alloys has been highlighted. To this end, the development, processing and biocompatibility of superelastic NiTi as well as resorbable magnesium-based alloys are discussed. Additionally, engineered porosity is reviewed as it can be an effective way of matching the stiffness of an implant with the surrounding tissue. These porosities and the overall geometry of the implant can be optimized for strain transduction and with a tailored stiffness profile. Rendering patient-specific, site-specific, morphology-specific and function-specific implants can now be achieved using these and other metals with bone-like material properties by additive manufacturing. The biocompatibility of implants prepared from superelastic and resorbable alloys is also reviewed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

An Overview of Internal Fixation Implant Metallurgy and Galvanic Corrosion Effects.

Science.gov (United States)

Koh, Justin; Berger, Aaron; Benhaim, Prosper

2015-08-01

Orthopedic and hand surgery implants for internal fixation of fractures have evolved substantially over the past 50 years. Newer metal compositions have been used, and new standards have been applied to older alloys, resulting in modern implants with unique physical properties and better clinical performances. Conventional wisdom has long dictated that implanting different metals should be avoided, but few guidelines exist regarding the safety of using in proximity implant systems of dissimilar metals. To better characterize the landscape of internal fixation implant metallurgy, we have compiled the recommendations and conclusions of the currently available and pertinent literature. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Ceramic Inclusions In Powder Metallurgy Disk Alloys: Characterization and Modeling

Science.gov (United States)

Bonacuse, Pete; Kantzos, Pete; Telesman, Jack

2002-01-01

Powder metallurgy alloys are increasingly used in gas turbine engines, especially as the material chosen for turbine disks. Although powder metallurgy materials have many advantages over conventionally cast and wrought alloys (higher strength, higher temperature capability, etc.), they suffer from the rare occurrence of ceramic defects (inclusions) that arise from the powder atomization process. These inclusions can have potentially large detrimental effect on the durability of individual components. An inclusion in a high stress location can act as a site for premature crack initiation and thereby considerably reduce the fatigue life. Because these inclusions are exceedingly rare, they usually don't reveal themselves in the process of characterizing the material for a particular application (the cumulative volume of the test bars in a fatigue life characterization is typically on the order of a single actual component). Ceramic inclusions have, however, been found to be the root cause of a number of catastrophic engine failures. To investigate the effect of these inclusions in detail, we have undertaken a study where a known population of ceramic particles, whose composition and morphology are designed to mimic the 'natural' inclusions, are added to the precursor powder. Surface connected inclusions have been found to have a particularly large detrimental effect on fatigue life, therefore the volume of ceramic 'seeds' added is calculated to ensure that a minimum number will occur on the surface of the fatigue test bars. Because the ceramic inclusions are irregularly shaped and have a tendency to break up in the process of extrusion and forging, a method of calculating the probability of occurrence and expected intercepted surface and embedded cross-sectional areas were needed. We have developed a Monte Carlo simulation to determine the distributions of these parameters and have verified the simulated results with observations of ceramic inclusions found in macro

Perspectives in metallurgical development. Proceedings of the centenary conference held at Ranmoor House, Sheffield, GB, on 16-18 July 1984

International Nuclear Information System (INIS)

1984-07-01

Forty one papers were presented on perspectives in metallurgical development, with sessions on historical metallurgy, extraction and process metallurgy, solidification processes, microstructural studies, working and forming, mechanical behaviour, corrosion and environmental effects, and future developments in metallurgy. One paper, on fracture mechanics and non-destructive testing related to assurance of structural integrity of nuclear pressure vessels, is indexed separately. (U.K.)

Advanced powder metallurgy aluminum alloys via rapid solidification technology

Science.gov (United States)

Ray, R.

1984-01-01

Aluminum alloys containing 10 to 11.5 wt. pct. of iron and 1.5 to 3 wt. pct. of chromium using the technique of rapid solidification powder metallurgy were studied. Alloys were prepared as thin ribbons (.002 inch thick) rapidly solidified at uniform rate of 10(6) C/second by the melt spinning process. The melt spun ribbons were pulverized into powders (-60 to 400 mesh) by a rotating hammer mill. The powders were consolidated by hot extrusion at a high reduction ratio of 50:1. The powder extrusion temperature was varied to determine the range of desirable processing conditions necessary to yield useful properties. Powders and consolidated alloys were characterized by SEM and optical metallography. The consolidated alloys were evaluated for (1) thermal stability, (2) tensile properties in the range, room temperature to 450 F, and (3) notch toughness in the range, room temperature to 450 F.

Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy

Directory of Open Access Journals (Sweden)

Sonia C. Ferreira

2014-12-01

Full Text Available Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp produced by powder metallurgy (PM were anodized under voltage control in tartaric-sulfuric acid (TSA. In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050 anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiCnp. The current peaks and the steady-state current density recorded at each voltage step increases with the SiCnp volume fraction due to the oxidation of the SiCnp. The formation mechanism of the anodic film on Al/SiCnp composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiCnp in the anodic film.

Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy

Science.gov (United States)

Ferreira, Sonia C.; Conde, Ana; Arenas, María A.; Rocha, Luis A.; Velhinho, Alexandre

2014-01-01

Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiCnp. The current peaks and the steady-state current density recorded at each voltage step increases with the SiCnp volume fraction due to the oxidation of the SiCnp. The formation mechanism of the anodic film on Al/SiCnp composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiCnp in the anodic film. PMID:28788295

Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy.

Science.gov (United States)

Ferreira, Sonia C; Conde, Ana; Arenas, María A; Rocha, Luis A; Velhinho, Alexandre

2014-12-19

Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiC np ) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiC np on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiC np . The current peaks and the steady-state current density recorded at each voltage step increases with the SiC np volume fraction due to the oxidation of the SiC np . The formation mechanism of the anodic film on Al/SiC np composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiC np in the anodic film.

Situation of radioactive wastes and their prevention and treatment measures in China's uranium mining and metallurgy

International Nuclear Information System (INIS)

Li Renjie.

1988-01-01

The sorts of radioactive wastes produced in uranium mining and metallurgy and their hazards are discribed in this paper. The characteristics of the radioactive wastes are discussed. The measurements and results are introduced for treatment and disposal of the radioactive wastes. The way to deal with prevention and treatment of radioactive wastes is presented in the stages of engineering design, construction, production and decommission of uranium mines and plants

Chemical Composition and Antioxidant Activity of Essential Oils and Methanol Extracts of Different Parts from Juniperus rigida Siebold & Zucc.

Science.gov (United States)

Liu, Qiaoxiao; Li, Dengwu; Wang, Wei; Wang, Dongmei; Meng, Xiaxia; Wang, Yongtao

2016-09-01

The chemical composition and antioxidant activity of essential oils and MeOH extracts of stems, needles, and berries from Juniperus rigida were studied. The results indicated that the yield of essential oil from stems (2.5%) was higher than from needles (0.8%) and berries (1.0%). The gas chromatography/mass spectrometer (GC/MS) analysis indicated that 21, 17, and 14 compounds were identified from stems, needles, and berries essential oils, respectively. Caryophyllene, α-caryophyllene, and caryophyllene oxide were primary compounds in both stems and needles essential oils. However, α-pinene and β-myrcene mainly existed in berries essential oils and α-ionone only in needles essential oils. The high-performance liquid chromatography (HPLC) analysis indicated that the phenolic profiles of three parts exhibited significant differences. Needles extracts had the highest content of chlorogenic acid, catechin, podophyllotoxin, and amentoflavone, and for berries extracts, the content of those compounds was the lowest. Meanwhile, three in vitro methods (DPPH, ABTS, and FRAP) were used to evaluate antioxidant activity. Stems essential oil and needles extracts exhibited the powerful antioxidant activity than other parts. This is the first comprehensive study on the different parts of J. rigida. The results suggested that stems and needles of J. rigida are useful supplements for healthy products as new resources. © 2016 Wiley-VHCA AG, Zürich.

[Possible health effects associated with Pre-Columbian metallurgy].

Science.gov (United States)

Idrovo, Alvaro Javier

2005-09-01

In the Old World, several researchers have indicated that adverse health effects were associated with exposure to arsenic, and that this influenced a change in the use of copper-arsenic alloys to others less toxic. This hypothesis was evaluated for three Pre-Columbian metallurgy traditions: Central Andes, Intermediate Area, and West Mexico. The metal artifacts from the Central Andes showed arsenic concentrations similar to those in the Old World (0.5%-1.0%). In the Intermediate Area the values were smallest; however, in West Mexico the arsenic content was very high (7%-25%). In Central Andes arsenical bronze was used initially, but copper-tin alloys when introduced were preferred and distributed throughout the Inca Empire. Osteological and artistic evidences of foot amputations among Moche individuals from Central Andes support the presence of "black foot disease" (a condition associated with arsenic poisoning) among Pre-Columbian populations. In conclusion, the adverse effects of arsenic have been observed in the New World, and that these effects promoted a change toward the use of less toxic alloys.

Biological Activities of Aerial Parts Extracts of Euphorbia characias

Directory of Open Access Journals (Sweden)

Maria Barbara Pisano

2016-01-01

Full Text Available The aim of the present study was to evaluate antioxidant, antimicrobial, anti-HIV, and cholinesterase inhibitory activities of aqueous and alcoholic extracts from leaves, stems, and flowers of Euphorbia characias. The extracts showed a high antioxidant activity and were a good source of total polyphenols and flavonoids. Ethanolic extracts from leaves and flowers displayed the highest inhibitory activity against acetylcholinesterase and butyrylcholinesterase, showing potential properties against Alzheimer’s disease. Antimicrobial assay showed that leaves and flowers extracts were active against all Gram-positive bacteria tested. The ethanolic leaves extract appeared to have the strongest antibacterial activity against Bacillus cereus with MIC value of 312.5 μg/mL followed by Listeria monocytogenes and Staphylococcus aureus that also exhibited good sensitivity with MIC values of 1250 μg/mL. Moreover, all the extracts possessed anti-HIV activity. The ethanolic flower extract was the most potent inhibitor of HIV-1 RT DNA polymerase RNA-dependent and Ribonuclease H with IC50 values of 0.26 and 0.33 μg/mL, respectively. The LC-DAD metabolic profile showed that ethanolic leaves extract contains high levels of quercetin derivatives. This study suggests that Euphorbia characias extracts represent a good source of natural bioactive compounds which could be useful for pharmaceutical application as well as in food system for the prevention of the growth of food-borne bacteria and to extend the shelf-life of processed foods.

Environmental legacy of copper metallurgy and Mongol silver smelting recorded in Yunnan Lake sediments.

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Hillman, Aubrey L; Abbott, Mark B; Yu, JunQing; Bain, Daniel J; Chiou-Peng, TzeHuey

2015-03-17

Geochemical measurements on well-dated sediment cores from Lake Er (Erhai) are used to determine the timing of changes in metal concentrations over 4500 years in Yunnan, a borderland region in southwestern China noted for rich mineral deposits but with inadequately documented metallurgical history. Our findings add new insight into the impacts and environmental legacy of human exploitation of metal resources in Yunnan history. We observe an increase in copper at 1500 BC resulting from atmospheric emissions associated with metallurgy. These data clarify the chronological issues related to links between the onset of Yunnan metallurgy and the advent of bronze technology in adjacent Southeast Asia, subjects that have been debated for nearly half a century. We also observe an increase from 1100 to 1300 AD in a number of heavy metals including lead, silver, zinc, and cadmium from atmospheric emissions associated with silver smelting. Culminating during the rule of the Mongols, known as the Yuan Dynasty (1271-1368 AD), these metal concentrations approach levels three to four times higher than those from industrialized mining activity occurring within the catchment today. Notably, the concentrations of lead approach levels at which harmful effects may be observed in aquatic organisms. The persistence of this lead pollution over time created an environmental legacy that likely contributes to known issues in modern day sediment quality. We demonstrate that historic metallurgical production in Yunnan can cause substantial impacts on the sediment quality of lake systems, similar to other paleolimnological findings around the globe.

Physical and mechanical metallurgy of high purity Nb for accelerator cavities

International Nuclear Information System (INIS)

Bieler, T.R.; Wright, N.T.; Pourboghrat, F.; Compton, C.; Hartwig, K.T.; Baars, D.; Zamiri, A.; Chandrasekaran, S.; Darbandi, P.; Jiang, H.; Skoug, E.; Balachandran, S.; Ice, G.E.; Liu, W.

2010-01-01

In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF) cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

High damping Al-Fe-Mo-Si/Zn-Al composites produced by rapidly solidified powder metallurgy process

International Nuclear Information System (INIS)

Li, P.Y.; Dai, S.L.; Chai, S.C.; Li, Y.R.

2000-01-01

The metallic materials commonly used in aircraft and aerospace fields, such as aluminum and titanium alloys, steels, etc., show extremely low damping capacity (usually of the order of or less than 10 -3 ). Thus, some problems related to vibration may emerge and influence the reliability, safety and life of airplanes, satellites, etc. It has been reported that almost two thirds of errors for rockets and satellites are related to vibration and noise. One effective way to solve these vibration-related problems is to adopt high damping metallic materials. Conventional high damping alloys exhibit damping capacity above 10 -2 , however, their densities are usually great than 5 x 10 3 kg m -3 , or their strengths are less than 200 MPa (for alloys based on dislocation damping), making them impossible to be applied to aircraft and aerospace areas. Recently, some low-density high-damping metal/metal composites based on aluminum and high damping alloys have been developed in Beijing Institute of Aeronautical Materials (BIAM) by the rapidly solidified power metallurgy process. This paper aims to report the properties of the composites based on a high temperature Al-Fe-Mo-Si alloy and a high damping Zn-Al alloy, and compare them with that of 2618-T61 alloy produced by the ingot metallurgy process

Effect of the methanolic extracts of different parts of Ferula assa-foetida on naloxone-induced withdrawal behavior in morphine-dependent mice

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Mahnaz Khanavi

2017-08-01

Full Text Available Objective: Ferula assa-foetida, a native species in Iran, is used for treatment of several diseases particularly for neurological disorders in Iranian Traditional Medicine. The aim of this study is to investigate the effect of methanolic roots, fruits, and aerial parts extracts of Ferula assa-foetida on withdrawal syndrome in morphine-dependent mice. Materials and Methods: Aerial parts, roots, and fruits of the plant were separately extracted with 80% MeOH. For induction of dependence, morphine (50, 50 and 75 mg/kg was injected subcutaneously three times daily (10 am, 1 pm and 4 pm for three days and a last dose of morphine (50 mg/kg was administrated on the fourth day. Withdrawal syndrome was induced by injection of naloxone (5 mg/kg, intraperitoneal 2 hr after the final dose of morphine. Different doses of the extracts were administered i.p. 60 minutes before naloxone injection and withdrawal sign was recorded 2 minutes after naloxone injection for a period of 60 minutes.   Results: Pre-treatment of animals with different doses (2.5, 5, 10, 20 mg/kg of methanolic extract of the aerial parts of F. assa-foetida caused a significant decrease in naloxone-induced behavior. Intraperitoneal administration of different doses (10, 15, 20, 25 mg/kg of methanolic extract of the fruit significantly reduced the naloxone-induced withdrawal behavior (p

Effects of maple (Acer) plant part extracts on proliferation, apoptosis and cell cycle arrest of human tumorigenic and non-tumorigenic colon cells.

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González-Sarrías, Antonio; Li, Liya; Seeram, Navindra P

2012-07-01

Phenolic-enriched extracts of maple sap and syrup, obtained from the sugar and red maple species (Acer saccharum Marsh, A. rubrum L., respectively), are reported to show anticancer effects. Despite traditional medicinal uses of various other parts of these plants by Native Americans, they have not been investigated for anticancer activity. Here leaves, stems/twigs, barks and sapwoods of both maple species were evaluated for antiproliferative effects against human colon tumorigenic (HCT-116, HT-29, Caco-2) and non-tumorigenic (CCD-18Co) cells. Extracts were standardized to total phenolic and ginnalin-A (isolated in our laboratory) levels. Overall, the extracts inhibited the growth of the colon cancer more than normal cells (over two-fold), their activities increased with their ginnalin-A levels, with red > sugar maple extracts. The red maple leaf extract, which contained the highest ginnalin-A content, was the most active extract (IC₅₀  = 35 and 16 µg/mL for extract and ginnalin-A, respectively). The extracts were not cytotoxic nor did they induce apoptosis of the colon cancer cells. However, cell cycle analyses revealed that the antiproliferative effects of the extracts were mediated through cell cycle arrest in the S-phase. The results from the current study suggest that these maple plant part extracts may have potential anticolon cancer effects. Copyright © 2011 John Wiley & Sons, Ltd.

The role of aqueous extract of pineapple fruit parts on the healing of acute crush tendon injury.

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Aiyegbusi, A I; Duru, F I O; Awelimobor, D; Noronha, C C; Okanlawon, A O

2010-01-01

The Pineapple plant contains the enzyme bromelain which has been acclaimed to reduce pain and swellings following acute muscle injuries as well as carotenoids and polyphenols which are powerful antioxidants. It is yet to be determined if these constituents are distributed throughout the plant and what effect they have on the healing of acute tendon injuries. This study therefore investigated the effects of the aqueous extract of different parts of the pineapple plant on tenoblast proliferation and the tendon Malondialdehyde (MDA) level in the early stage of healing in a crush injury to the achilles tendon of Sprague-Dawley rats. Forty male rats were divided randomly into five groups; all had induced crush injury to the left Achilles tendon. Group 1; injury and nil treatment, Group 2; leaves extract, Group 3; fruit flesh extract, Group 4; bark extract, Group 5; core extract. The extract was given at a dosage of 30 mg/kg body weight daily over the first 14 days post-injury. On the 15th day post injury, the animals were sacrificed and the tendons excised and processed for histological study and MDA assay. The flesh and bark extract induced a proliferation of tenoblasts which however was not significantly different from that of the untreated tendon while the leaves and core extracts reduced the population of the tenocytes. The flesh extract significantly (p leaves and core extract significantly (p pineapple plant are concentrated in the flesh while the bark and flesh extracts have the potential to promote healing by stimulating tenoblast proliferation.

Innovative Extraction Method for a Coal Seam with a Thick Rock-Parting for Supporting Coal Mine Sustainability

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Meng Li

2017-10-01

Full Text Available As thick rock partings delay the efficient mining of coal seams and constrain the sustainable development of coal mines, an innovative extraction method for a coal seam with thick rock parting was proposed. The coal seams were divided into different sub-zones according to the thickness of rock parting and then the sub-zones were mined by separately using three mining schemes involving full-seam mining, combined mining using backfill and caving (CMBC, and reducing height mining. Afterwards, the study introduced the basic mechanism and key devices for the CMBC and analysed the working state of the backfill support in detail. Moreover, the method for calculating the length of the backfill zone was proposed to design the length of backfill zone and the influences of four factors (including bulking coefficient of rock parting on the length of the backfill zone were also explored. By taking the No. 22203 panel, Buertai mine, Inner Mongolia, China as an example, the mined coal resource by using the CMBC extraction method will increase by 1.83 × 106 tons and the recovery ratio will rise from 56.2% to 92.4% compared with mining of the 2-2 upper coal seam alone. Moreover, by applying CMBC, a series of environmental and ecological problems caused by rock parting is reduced, which can improve the environment in mined areas. The research can provide technological guidance for mining panels of a coal seam with a thick rock parting and the disposal thereof under similar conditions.

Microstructure and properties of powder metallurgy (PM) high alloy tool steels

International Nuclear Information System (INIS)

Wojcieszynski, A.L.; Eisen, W.B.; Dixon, R.B.

1998-01-01

Particle metallurgy (PM) processing is currently the primary manufacturing method used to produce advanced high alloy tool steel compositions for use in industrial tooling applications. This process involves gas atomization of the pre-alloyed melt to form spherical powders and consolidation by HIP to full density. The HIP product may be used directly in select applications, but is usually subjected to additional forging to improve properties and produce a wide range of bar and plate sizes. Compared to ingot-cast tool steels, PM tool steels have very homogeneous microstructures with very fine carbide and sulfide size distributions, free from carbide banding, which results in improved machinability, grindability, and mechanical properties. In addition, this technology enables the development of advanced tool steel compositions which could not be economically produced by conventional steelmaking. (author)

Physical and mechanical metallurgy of high purity Nb for accelerator cavities

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T. R. Bieler

2010-03-01

Full Text Available In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

Effects of fine porosity on the fatigue behavior of a powder metallurgy superalloy

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Miner, R. V.; Dreshfield, R. L.

1980-01-01

Hot-isostatically-pressed powder-metallurgy Astroloy was obtained which contained 1.4 percent porosity at the grain boundaries produced by argon entering the powder container during pressing. This material was tested at 650 C in fatigue, creep-fatigue, tension, and stress-rupture and the results compared with data on sound Astroloy. They influenced fatigue crack initiation and produced a more intergranular mode of propagation but fatigue life was not drastically reduced. Fatigue behavior of the porous material showed typical correlation with tensile behavior. The plastic strain range-life relation was reduced proportionately with the reduction in tensile ductility, but the elastic strain range-life relation was changed little.

Accelerated Near-Threshold Fatigue Crack Growth Behavior of an Aluminum Powder Metallurgy Alloy

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Piascik, Robert S.; Newman, John A.

2002-01-01

Fatigue crack growth (FCG) research conducted in the near threshold regime has identified a room temperature creep crack growth damage mechanism for a fine grain powder metallurgy (PM) aluminum alloy (8009). At very low DK, an abrupt acceleration in room temperature FCG rate occurs at high stress ratio (R = Kmin/Kmax). The near threshold accelerated FCG rates are exacerbated by increased levels of Kmax (Kmax less than 0.4 KIC). Detailed fractographic analysis correlates accelerated FCG with the formation of crack-tip process zone micro-void damage. Experimental results show that the near threshold and Kmax influenced accelerated crack growth is time and temperature dependent.

Maytenus salicifolia Reissek, Celastraceae: triterpenes isolated from stems and antioxidant property of extracts from aerial parts

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Cássia G. Magalhães

2011-06-01

Full Text Available Six pentacyclic triterpenes were isolated from hexane extract of stems of Maytenus salicifolia Reissek, Celastraceae: 30-hydroxyfriedelan-3-one (1, 3,16-dioxofriedelane (2, friedeline (3, lupeol (4, betuline (5 and lup-20(29-en-3,30-diol (6. The structure each one was established on the basis of detailed ¹H and 13C NMR spectral investigation and by comparison with the respective literature values. For compound 1, the complete 2D NMR (HMBC, HMQC and NOESY spectral data were herein reported for the first time. Compounds 1, 2, 5 and 6 were isolated for the first time from this plant. Antioxidant activity is described for some extracts from species of the Celastraceae family, then, the extracts from aerial parts of M. salicifolia were evaluated in relation to antioxidant potential using the DPPH method. Compared to quecertin, the AcEt extract (EAF from leaves, AcEt (EAPF and MeOH (EMPF from pulp fruit and AcEt (EAT and MeOH (EMT from stems showed significant antioxidant property.

Mechanical Properties of Lightweight Porous Magnesium Processed Through Powder Metallurgy

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Zou, Ning; Li, Qizhen

2018-02-01

Porous magnesium (Mg) samples with various overall porosities (28.4 ± 1.8%, 35.5 ± 2.5%, 45.4 ± 1.9%, and 62.4 ± 2.2%) were processed through powder metallurgy and characterized to study their mechanical properties. Different porosities were obtained by utilizing different mass fractions of space holder camphene. Camphene was removed by sublimation before sintering and contributed to processing porous Mg with high purity and small average pore size. The average pore size increased from 5.2 µm to 15.1 µm with increase of the porosity from 28.4 ± 1.8% to 62.4 ± 2.2%. Compressive strain-stress data showed that the strain hardening rate, yield strength, and ultimate compressive strength decreased with increase of the porosity. The theoretical yield strength of porous Mg obtained using the Gibson-Ashby model agreed with experimental data.

Powder metallurgy and mechanical alloying effects on the formation of thermally induced martensite in an FeMnSiCrNi SMA

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Pricop Bogdan

2015-01-01

Full Text Available By ingot metallurgy (IM, melting, alloying and casting, powder metallurgy (PM, using as-blended elemental powders and mechanical alloying (MA of 50 % of particle volume, three types of FeMnSiCrNi shape memory alloy (SMA specimens were fabricated, respectively. After specimen thickness reduction by hot rolling, solution treatments were applied, at 973 and 1273 K, to thermally induce martensite. The resulting specimens were analysed by X-ray diffraction (XRD and scanning electron microscopy (SEM, in order to reveal the presence of ε (hexagonal close-packed, hcp and α’ (body centred cubic, bcc thermally induced martensites. The reversion of thermally induced martensites, to γ (face centred cubic, fcc austenite, during heating, was confirmed by dynamic mechanical analysis (DMA, which emphasized marked increases of storage modulus and obvious internal friction maxima on DMA thermograms. The results proved that the increase of porosity degree, after PM processing, increased internal friction, while MA enhanced crystallinity degree.

State space model extraction of thermohydraulic systems – Part I: A linear graph approach

International Nuclear Information System (INIS)

Uren, K.R.; Schoor, G. van

2013-01-01

Thermohydraulic simulation codes are increasingly making use of graphical design interfaces. The user can quickly and easily design a thermohydraulic system by placing symbols on the screen resembling system components. These components can then be connected to form a system representation. Such system models may then be used to obtain detailed simulations of the physical system. Usually this kind of simulation models are too complex and not ideal for control system design. Therefore, a need exists for automated techniques to extract lumped parameter models useful for control system design. The goal of this first paper, in a two part series, is to propose a method that utilises a graphical representation of a thermohydraulic system, and a lumped parameter modelling approach, to extract state space models. In this methodology each physical domain of the thermohydraulic system is represented by a linear graph. These linear graphs capture the interaction between all components within and across energy domains – hydraulic, thermal and mechanical. These linear graphs are analysed using a graph-theoretic approach to derive reduced order state space models. These models capture the dominant dynamics of the thermohydraulic system and are ideal for control system design purposes. The proposed state space model extraction method is demonstrated by considering a U-tube system. A non-linear state space model is extracted representing both the hydraulic and thermal domain dynamics of the system. The simulated state space model is compared with a Flownex ® model of the U-tube. Flownex ® is a validated systems thermal-fluid simulation software package. - Highlights: • A state space model extraction methodology based on graph-theoretic concepts. • An energy-based approach to consider multi-domain systems in a common framework. • Allow extraction of transparent (white-box) state space models automatically. • Reduced order models containing only independent state

The traces of roman metallurgy in Eastern Serbia

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Petković Sofija

2009-01-01

Full Text Available The archaeological traces of the Roman mining and metallurgy in eastern Serbia are rather frequent but insufficiently studied and published. Three mining-metallurgical regions abounding in gold, silver, copper, iron and lead could be distinguished there: 1. the upper course of the Pek river, metalla Pincensia, 2. the area between Bor, Zlot, Crna Reka and Rgotina and 3. the area in the river basin of Beli Timok, two latter ones had been organized as territoria metallorum. The archeometallurgical sites confirmed by investigations are: Kraku lu Jordan at the confluence of the Brodica river and the Pek river, Rudna Glava, Tilva Roš in Bor, Gamzigrad - Romuliana, Rgotina near Zaječar and Timacum Minus in the village Ravna near Knjaževac. Roman mining-metallurgical activities in eastern Serbia flourished from the end of the 3rd century, were interrupted by the invasion of Huns in AD 441. and restored in the time of emperors Anastasius and Justin I, in the end of the 5th - beginning of the 6th centuries. The Roman mining-metallurgical centers functioned in the 6th century until the Slav invasion in the beginning of the 7th century.

Study of alumina-trichite reinforcement of a nickel-based matric by means of powder metallurgy

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Walder, A.; Hivert, A.

1982-01-01

Research was conducted on reinforcing nickel based matrices with alumina trichites by using powder metallurgy. Alumina trichites previously coated with nickel are magnetically aligned. The felt obtained is then sintered under a light pressure at a temperature just below the melting point of nickel. The halogenated atmosphere technique makes it possible to incorporate a large number of additive elements such as chromium, titanium, zirconium, tantalum, niobium, aluminum, etc. It does not appear that going from laboratory scale to a semi-industrial scale in production would create any major problems.

The decision to extract: part II. Analysis of clinicians' stated reasons for extraction.

Science.gov (United States)

Baumrind, S; Korn, E L; Boyd, R L; Maxwell, R

1996-04-01

In a recently reported study, the pretreatment records of each subject in a randomized clinical trial of 148 patients with Class I and Class II malocclusions presenting for orthodontic treatment were evaluated independently by five experienced clinicians (drawn from a panel of 14). The clinicians displayed a higher incidence of agreement with each other than had been expected with respect to the decision as to whether extraction was indicated in each specific case. To improve our understanding of how clinicians made their decisions on whether to extract or not, the records of a subset of 72 subjects randomly selected from the full sample of 148, have now been examined in greater detail. In 21 of these cases, all five clinicians decided to treat without extraction. Among the remaining 51 cases, there were 202 decisions to extract (31 unanimous decision cases and 20 split decision cases). The clinicians cited a total of 469 reasons to support these decisions. Crowding was cited as the first reason in 49% of decisions to extract, followed by incisor protrusion (14%), need for profile correction (8%), Class II severity (5%), and achievement of a stable result (5%). When all the reasons for extraction in each clinician's decision were considered as a group, crowding was cited in 73% of decisions, incisor protrusion in 35%, need for profile correction in 27%, Class II severity in 15% and posttreatment stability in 9%. Tooth size anomalies, midline deviations, reduced growth potential, severity of overjet, maintenance of existing profile, desire to close the bite, periodontal problems, and anticipation of poor cooperation accounted collectively for 12% of the first reasons and were mentioned in 54% of the decisions, implying that these considerations play a consequential, if secondary, role in the decision-making process. All other reasons taken together were mentioned in fewer than 20% of cases. In this sample at least, clinicians focused heavily on appearance

Antifungal Activity of Aqueous Extracts from Ferula Assa foetida Aerial parts on Candida Albicans and its Comparison with Fluconazole in vitro

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AA Jafari

2014-09-01

Results:Concentrations of 8.75 mg/ml aerial parts of Ferula assafoetida completely inhibited the growth of Candida albicans and killed all viable cells (MFC. Concentrations of 0.273 and 4.4 mg/ml Ferula aqueous extracts were also determined as MIC50 and MIC90. In case of Fluconazole, 128 µg/ml concentrationis determined as MFC and 0.5 µg/ml concentration is also known as MIC50. Conclusion:Results of the current study showed that the aqueous extract of Ferula assafoetida aerial parts has inhibitory and candidacidal effect against Candida albicans and further in vivo studies are suggested.

New evidence for prehistoric copper metallurgy in the vicinity of Bor

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Kapuran Aleksandar

2016-01-01

Full Text Available The last three years of archaeological investigations at the site Ru`ana in Banjsko Polje, in the immediate vicinity of Bor, have provided new evidence regarding the role of non-ferrous metallurgy in the economy of the prehistoric communities of north-eastern Serbia. The remains of metallurgical furnaces and a large amount of metallic slags at two neighbouring sites in the mentioned settlement reveal that locations with many installations for the thermal processing of copper ore existed in the Bronze Age. We believe, judging by the finds of material culture, that metallurgical activities in this area also continued into the Iron Age and, possibly, into the 4th century AD. [Projekat Ministarstva nauke Republike Srbije, br. 177020: Archaeology of Serbia: Cultural identity, integration factors, technological processes and the role of the central Balkans in the development of European prehistory

Niobium-base superalloys via powder metallurgy technology

International Nuclear Information System (INIS)

Loria, E.A.

1987-01-01

This paper provides some insight into an area that has been neglected, namely the possibility of developing high-strength, niobium-base alloys by improved oxidation resistance via the consolidation of rapidly solidified powders. Powder metallurgy (P/M) is an attractive processing technique because of its flexibility and versatility, and it may provide the alloys with properties and workability not obtainable via metal casting. A critical review of both U.S. and Russian literature is presented along with suggestions on the most promising compositions and processing techniques available to meet these competing goals. Previous work on many niobium alloys reveals that long term properties are retained well above those obtained on nickel-base superalloys. Cast and wrought alloys extend specific strength beyond 1200 0 C (2200 0 F), but lack oxidation resistance. Remarkable oxidation resistance is obtained, however, on miniature castings of certain ternary alloys which are too brittle for any processing. A better understanding of the oxidation mechanism is necessary before the proper P/M (RST) approach is taken on compositions which could provide compatibility between the two competing goals through grain refinement and a homogeneous distribution of the contributory phases. Finally, ways to up-scale production of Nb powder are discussed, including thermodynamic feasibility for the direct reduction of NbCl/sub 5/ in a 1.5 MW plasma reactor

The Metallurgy of some indian swords

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Williams, Alan

2007-12-01

Full Text Available The metallurgy of Indian swords shows many differences from that of European swords. The distinction between "Damascus Steel" (or wootz and crucible steel is explained. Ten broken blades from the Armoury of the Nizams of Hyderabad were made available for microscopic examination. Six of these seem to been made from crucible steels, and are of notably high quality. By contrast, a group of six randomly collected from Private Collections in England were also examined. Only one of these was made of crucible steel, and three of the others were of very mediocre quality. This perhaps represents the quality of blades available to the average Indian soldier.

La metalurgia de las espadas indias presenta notables diferencias en comparación con la de las europeas. Se explica la distinción entre el ‘acero de Damasco’ (o wootz y el acero de crisol. Se ha realizado un análisis microscópico de un conjunto de diez hojas rotas de espada depositadas en la Armería de los Nizams de Hyderabad. Seis de ellas parecen haber sido realizadas a partir de acero de crisol, y son de elevada calidad. En contraste, se examinó también un grupo de seis espadas de colecciones privadas en Inglaterra. Sólo una de ellas estaba fabricada con acero de crisol, y tres de las otras eran de calidad muy mediocre. Esto representa quizá la calidad de las hojas de espada al alcance del soldado medio indio.

Properties of powder metallurgy steel forgings

International Nuclear Information System (INIS)

Crowson, A.; Anderson, F.E.

1977-01-01

The effects of processing variables on the mechanical properties of heat-treated powder metallurgy (P/M) steel forgings were determined. Prealloyed 4600 steel powder blended with graphite to yield 4640 was compacted into preforms and hot forged in a warm, closed die. Variables studied were preform density, method of lubrication, preform sintering (time, temperature and atmosphere), forging pressure (20 and 40 tsi) and temperature (1850 0 F, 2000 0 F and 2200 0 F), and forging ratio (0.75 and 0.95). Relationships between interconnected porosity and total porosity for the various preform densities were determined. High density compacts required higher sintering temperatures due to the restricted mobility of the reducing gases in the pores. Die wall lubrication was comparable to admixed lubrication, and it simplified powder mixing and preform sintering operations. Forgings with densities from 99 to 99.8 percent of theoretical density were attained with a forging pressure of 20 to 40 tsi and preform temperatures of 2000 0 F and above. At forging conditions which resulted in forgings with acceptable mechanical properties, complete die fill was accomplished at a forging ratio of 0.95, whereas incomplete die fill resulted at a forging ratio of 0.75. The response of P/M forgings to heat treatment was comparable to that for wrought materials, and the resultant tensile and yield strengths were equivalent to the strength values described for wrought 4640 steel in AMS specification 6317B. In addition, ductility and impact properties of P/M forgings with near theoretical density (99.5+ percent) were comparable to bar stock forgings

Finite element simulation of HIP-process to produce 3d near net shape parts

International Nuclear Information System (INIS)

Zadeh, M.K.

1996-01-01

One of the major problems when producing powder metallurgy parts through hot isostatic pressing (HIP) is the non homogeneous shrinkage of HIP-capsule during the process. This leads to time and cost consuming machining of the HIP parts. In order to reduce the machining to a minimum, one can try to simulate the HIP-process by means of numerical methods. Hereby, the part distortion can be predicted, and hence a new HIP-capsule can be designed in such a way to prevent the distortion partly or even completely. In the following, a finite element method is used, on one hand, to simulate part shrinkage during HIP process; on the other hand a method is integrated in this simulation to optimize the HIP-capsule geometry. For the determination of material dependent parameters, a mixture of theoretical and experimental methods is used. Results of simulation are verified for a complex 3d HIP part out of TiAl6V4

Chemical Variability and Biological Activities of Brassica rapa var. rapifera Parts Essential Oils Depending on Geographic Variation and Extraction Technique.

Science.gov (United States)

Saka, Boualem; Djouahri, Abderrahmane; Djerrad, Zineb; Terfi, Souhila; Aberrane, Sihem; Sabaou, Nasserdine; Baaliouamer, Aoumeur; Boudarene, Lynda

2017-06-01

In the present work, the Brassica rapa var. rapifera parts essential oils and their antioxidant and antimicrobial activities were investigated for the first time depending on geographic origin and extraction technique. Gas-chromatography (GC) and GC/mass spectrometry (MS) analyses showed several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, terpenic, nitrogen and sulphur compounds, totalizing 38 and 41 compounds in leaves and root essential oils, respectively. Nitrogen compounds were the main volatiles in leaves essential oils and sulphur compounds were the main volatiles in root essential oils. Qualitative and quantitative differences were found among B. rapa var. rapifera parts essential oils collected from different locations and extracted by hydrodistillation and microwave-assisted hydrodistillation techniques. Furthermore, our findings showed a high variability for both antioxidant and antimicrobial activities. The highlighted variability reflects the high impact of plant part, geographic variation and extraction technique on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on these factors, in order to isolate the bioactive components or to have the best quality of essential oil in terms of biological activities and preventive effects in food. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

Effect of sintering conditions on the microstructural and mechanical characteristics of porous magnesium materials prepared by powder metallurgy.

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Čapek, Jaroslav; Vojtěch, Dalibor

2014-02-01

There has recently been an increased demand for porous magnesium materials in many applications, especially in the medical field. Powder metallurgy appears to be a promising approach for the preparation of such materials. Many works have dealt with the preparation of porous magnesium; however, the effect of sintering conditions on material properties has rarely been investigated. In this work, we investigated porous magnesium samples that were prepared by powder metallurgy using ammonium bicarbonate spacer particles. The effects of the purity of the argon atmosphere and sintering time on the microstructure (SEM, EDX and XRD) and mechanical behaviour (universal loading machine and Vickers hardness tester) of porous magnesium were studied. The porosities of the prepared samples ranged from 24 to 29 vol.% depending on the sintering conditions. The purity of atmosphere played a significant role when the sintering time exceeded 6h. Under a gettered argon atmosphere, a prolonged sintering time enhanced diffusion connections between magnesium particles and improved the mechanical properties of the samples, whereas under a technical argon atmosphere, oxidation at the particle surfaces caused deterioration in the mechanical properties of the samples. These results suggest that a refined atmosphere is required to improve the mechanical properties of porous magnesium. © 2013.

Analysis of cancer mortality risk among workers of a research uranium metallurgy division in France

International Nuclear Information System (INIS)

Jejati, H.; Laurier, D.; Tirmarche, M.; Giraud, J.M.

1997-01-01

This cohort study has been undertaken in response to a suspected cluster of cancers mentioned by workers involved in research activities concerning the metallurgy of uranium. The studied population included all persons having worked between 1950 and 1968 at the Metallurgy Division of the French Atomic Energy Commission (CEA). Exposures were registered on an individual annual basis. For analysis, they were grouped in three categories: use of chemicals agents (Benzene, beryllium, alcohols, solvents ...), manipulation of radioactive materials (uranium, thorium, fission decay products), and exposure to external radiation. This relatively small cohort included 356 workers followed up to December 1990. Out of observed deaths, 21 were from cancer. Total mortality from cancer was less than expected from national rates (Standardised Mortality Ratio = 0.73). Cancer mortality did not increase with duration of exposure to external radiation or with duration of manipulation of radioactive materials. Risk of cancer was increasing with the number of years of exposure to chemicals. The small size of this cohort limits the conclusion of the observed results. The purpose, despite this lack of power, was to answer a worry of the workers, more than to estimate a clear dose-response relationship linked to a specific cancer site. The effect studied here is ''all cancers'', a distinction of the different sites being uninformative because of the very small number of cases observed. Nevertheless, this study suggests some routes for further research: it highlights the importance of considering concomitant exposures like chemical ones in studies of nuclear workers. (author)

Functional dependency between the logistics security system and the MySAP ERP in metallurgy

Directory of Open Access Journals (Sweden)

P. Ranitović

2013-10-01

Full Text Available MySAP ERP - Enterprise Resource Planning (system - solution which provides a whole set of functions for the business analytics, finance, human resources management, logistics and corporate services has developed from SAP R/3. It is one of the main products of the SAP AG German multinational company and as such, it is a very important element of the international industrial and technological security system. By defining the functional dependency between the security systems (logistics security systems and the IT (My SAP ERP systems in metallurgy, a concept for designing MY SAP ERP system in metallurgic industry is defined, based on the security aspects.

Intraspecific variability of Holostylis reniformis: concentration of lignans, as determined by maceration and supercritical fluid extraction (SFE-CO2), as a function of plant provenance and plant parts

International Nuclear Information System (INIS)

Martins, Gislaine F.; Pereira, Marcos D.P.; Lopes, Lucia M.X.; Krettli, Antoniana U.

2014-01-01

Maceration and supercritical fluid extraction were used to prepare extracts from parts of plants (Holostylis reniformis) collected in two different regions of Brazil. 1 H NMR, HPLC-DAD-ESI/MS, HPLC-DAD, GC-MS, and chemometric techniques were used to analyse lignans in the extracts and showed that yields of SFE-CO 2 were less than or equal to those of hexane maceration extracts. These analyses, in conjunction with the concentrations of aliphatic hydrocarbons, fatty acids and their methyl and ethyl derivatives in the extracts, also allowed the chemical composition of parts and provenance of the plant to be differentiated. (author)

Evaluation of Antioxidant Activities of Aqueous Extracts and Fractionation of Different Parts of Elsholtzia ciliata

Directory of Open Access Journals (Sweden)

Yuangang Zu

2012-05-01

Full Text Available The aim of this study was to investigate the antioxidant and free-radical scavenging activity of extract and fractions from various parts of Elsholtzia ciliata. The inflorescences, leaves, stems and roots of E. ciliata were extracted separately and two phenolic component enrichment methods: ethyl acetate-water liquid-liquid extraction and macroporous resin adsorption-desorption, were adopted in this study. The antioxidant activities of water extracts and fractions of E. ciliata were examined using different assay model systems in vitro. The fraction root E (purified by HPD300 macroporous resin exhibited the highest total phenolics content (497.2 ± 24.9 mg GAE/g, accompanied with the highest antioxidant activity against various antioxidant systems in vitro compared to other fractions. On the basis of the results obtained, E. ciliata extracts can be used potentially as a ready accessible and valuable bioactive source of natural antioxidants.

Annual report of the Metallurgy Division [for the] period ending December 1976

International Nuclear Information System (INIS)

Elayaperumal, K.; Gupta, C.K.; Mukhopadhyay, P.; Rao, S.V.K.

1977-01-01

An account of the work done in the Metallurgy Division of the Bhabha Atomic Research Centre, Bombay, during the calendar year 1976 is given. Some of the major achievements are: (1) production of boron carbide and boral sheet for the Trombay R-5 reactor under construction, (2) production of niobium metal for the manufacture of Zr-Nb-Cu alloy garter springs, (3) development of a process for graphite coating on zircaloy, (4) studies on structural and metal physics aspects of zirconium alloys and steels, (5) studies on the corrosion behaviour of zircaloy-2 as affected by the replacement of helium and stress corrosion cracking of zircaloy fuel tubes in iodine atmosphere and (6) production of high density UO 2 pellets with stable microstructures and sinterable magnesium oxide for MHD application. (M.G.B.)

[The organization of the comprehensive prevention of urolithiasis among ferrous metallurgy workers].

Science.gov (United States)

Egorova, A M

2009-01-01

The purpose of study is to evaluate the effectiveness of the set of preventive measures as applied to 321 workers of basic ferrous metallurgy specialties (steel makers, mill men, hot metal shearers). During the clinical examination all the workers were divided on three groups: the workers without any pathology (11.83%, the first group), the workers with metabolic disorders only without urolitiasis (64.81%, the second group) and the workers with urolitiasis diagnosis approved by ultrasonography (23.36%, the third group). The effectiveness of rehabilitation measures was evaluated during half a year (diet therapy, drinking regimen, medicinal plants treatment). After the course of preventive measures was applied the overall health condition of most workers ameliorated and the number of workers with urolitiasis development risk factors reliably decreased up to 6-12%.

[Factors of working environment and process on non-ferrous metallurgy enterprises in Bashkortostan Republic and workers' occupational health].

Science.gov (United States)

Bakirov, A B; Takaev, R M; Kondrova, N S; Shaĭkhlislamova, E R

2011-01-01

The authors studied factors of working environment and process on nonferrous metallurgy enterprises in Bashkortostan Republic and evaluated their influence on the workers' occupational health over 1997-2009, with consideration of occupation, sex, age, length of service, work conditions and characters. The article demonstrates that sanitary and hygienic characteristics of occupations connected with machinery operation are prone to increased integral evaluation of work conditions due to underestimation of actual hardiness and intensity of work.

Design of powder metallurgy titanium alloys and composites

International Nuclear Information System (INIS)

Liu, Y.; Chen, L.F.; Tang, H.P.; Liu, C.T.; Liu, B.; Huang, B.Y.

2006-01-01

Low cost and good performance are two major factors virtually important for Ti alloy development. In this paper, we have studied the effects of alloying elements, thermo-mechanical treatment and particle reinforcement on microstructures and mechanical properties of powder metallurgy (PM) Ti alloys and their composites. Our results indicate that low cost PM Ti alloys and their composites with attractive properties can be fabricated through a single compaction-sintering process, although secondary treatments are required for high performance applications. Three new PM Ti alloys and one TiC/Ti composite of high performance are developed, and new design principles are also proposed. For design of PM Ti alloys, addition of alloying elements has the beneficial effect of enhanced sintering and/or improved mechanical properties. For example, Fe element accelerates the sintering process, Mo and Al are good candidates for solution strengthening, and rare earth elements effectively increase the material ductility by scavenging oxygen from the Ti matrix. For the design of Ti-based composites, in situ formation of strengthening particles and solid solution hardening of the matrix both should be considered simultaneously for alloy development. Cr 3 C 2 is found to be a very suitable additive for processing particle reinforced Ti composites

Synergistic extraction of actinides : Part I. Hexa-and pentavalent actinides

International Nuclear Information System (INIS)

Patil, S.K.; Ramakrishna, V.V.

1980-01-01

A detailed discussion on the reported literature on the synergistic extraction of hexa- and pentavalent actinide ions, by different combinations of extractants and from different aqueous media, is presented. Structural aspects of the various complexes involved in synergism also are reviewed. A short account of the applications based on synergistic extraction is also given. (author)

Physiological effects induced by the hydroalcoholic extract of Violae tricoloris herba (wild pansy aerial parts on Triticum aestivum L

Directory of Open Access Journals (Sweden)

Ruxandra Cretu

2011-12-01

Full Text Available Wild pansy (Viola tricolor hydroalcoholic extract was prepared by extraction of powdered dried – flowering aerial parts with ethanol 70% v/v (1:10, by reflux for two hours. This was diluted with distilled water to give the final concentrations of 0.5, 1.0 and 5% (v/v (VTEx1, VTEx2 and VTEx3. These extracts were tested for their effects on seed germination and seedlings growth of wheat (Triticum aestivum in a laboratory experiment. Distilled water was used as a control (C. After the 10 days of experiment, we evaluated seed germination of wheat and seedlings growth (roots and shoots lengths, their fresh and dry biomass.

Influence of Extraction Parameters on Hydroalcohol Extracts of the ...

African Journals Online (AJOL)

The parameter that had the greatest influence on extraction process was alcohol concentration ... rules and processing steps [2]. As part .... Table 1: Extractive batch nnumbers with the respective factors and levels studied in the factorial design.

Understanding extractive bleed : wood extractives: distribution, properties, and classes

Science.gov (United States)

Edward Burke; Norm Slavik; Tony Bonura; Dennis Connelly; Tom Faris; Arnie Nebelsick; Brent Stuart; Sam Williams; Alex C. Wiedenhoeft

2010-01-01

Color, odor, and natural durability of heartwood are characteristics imparted by a class of chemicals in wood known collectively extractives. Wood is converted by the tree from sapwood to heartwood by the deposition of extractives, typically many years after the growth ring undergoing this change was formed by the tree. Extractives are thus not a part of the wood...

Extracting recurrent scenarios from narrative texts using a Bayesian network: application to serious occupational accidents with movement disturbance.

Science.gov (United States)

Abdat, F; Leclercq, S; Cuny, X; Tissot, C

2014-09-01

A probabilistic approach has been developed to extract recurrent serious Occupational Accident with Movement Disturbance (OAMD) scenarios from narrative texts within a prevention framework. Relevant data extracted from 143 accounts was initially coded as logical combinations of generic accident factors. A Bayesian Network (BN)-based model was then built for OAMDs using these data and expert knowledge. A data clustering process was subsequently performed to group the OAMDs into similar classes from generic factor occurrence and pattern standpoints. Finally, the Most Probable Explanation (MPE) was evaluated and identified as the associated recurrent scenario for each class. Using this approach, 8 scenarios were extracted to describe 143 OAMDs in the construction and metallurgy sectors. Their recurrent nature is discussed. Probable generic factor combinations provide a fair representation of particularly serious OAMDs, as described in narrative texts. This work represents a real contribution to raising company awareness of the variety of circumstances, in which these accidents occur, to progressing in the prevention of such accidents and to developing an analysis framework dedicated to this kind of accident. Copyright © 2014 Elsevier Ltd. All rights reserved.

Encyclopedic dictionary bilingual English-Spanish of sciences: mining, chemistry, geology, metallurgy and environment

International Nuclear Information System (INIS)

Munoz Maradona, M.; Bellini, M.; Busleiman, M.

2007-01-01

This dictionary has been designed to satisfy scientists, researchers, technicians, interpreters, translators and students' needs in the areas of chemistry, geology, mining, metallurgy and environment for they find it necessary to have an English- Spanish encyclopedia on their sciences. It is a reliable book when looking for words that are normally not included in everyday dictionaries. It is now reaching the final revision stage with more than 15,000 entries. It includes scientific terms, chemical formulas of minerals and other elements, noticeable scientists' biographies, tables, graphics, and images so as to help readers' understanding. It is divided into three columns: the first one presents the English term and its area of concern; the second, the corresponding Spanish equivalent, and in the third, a suitable explanation.(author)

Vacuum extraction

DEFF Research Database (Denmark)

Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

2012-01-01

Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two-part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validation of the developed OSATS scale for vac...

Intraspecific variability of Holostylis reniformis: concentration of lignans, as determined by maceration and supercritical fluid extraction (SFE-CO{sub 2}), as a function of plant provenance and plant parts

Energy Technology Data Exchange (ETDEWEB)

Martins, Gislaine F.; Pereira, Marcos D.P.; Lopes, Lucia M.X., E-mail: lopesxl@iq.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Araraquara, SP (Brazil). Instituto de Quimica; Silva, Tito da [Universidade Federal do Maranhao (UFMA), Imperatriz, MA (Brazil). Centro de Ciencias Sociais, Saude e Tecnologia; Rosa, Paulo de T. Vieira e; Barbosa, Fernanda P. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica; Messiano, Gisele B. [Instituto Federal de Sao Paulo, SP (Brazil); Krettli, Antoniana U. [Fundacao Oswaldo Cruz (FIOCRUZ), Belo Horizonte, MG (Brazil). Instituto Rene Rachou

2014-04-15

Maceration and supercritical fluid extraction were used to prepare extracts from parts of plants (Holostylis reniformis) collected in two different regions of Brazil. {sup 1}H NMR, HPLC-DAD-ESI/MS, HPLC-DAD, GC-MS, and chemometric techniques were used to analyse lignans in the extracts and showed that yields of SFE-CO{sub 2} were less than or equal to those of hexane maceration extracts. These analyses, in conjunction with the concentrations of aliphatic hydrocarbons, fatty acids and their methyl and ethyl derivatives in the extracts, also allowed the chemical composition of parts and provenance of the plant to be differentiated. (author)

Metallurgical joining of engine parts. Inertia welding of nickel superalloy HP compressor disks

International Nuclear Information System (INIS)

Ferte, J.P.

1993-01-01

The main part of this paper describes upside metallurgical and mechanical work done at SNECMA, on inertia welding of powder metallurgy nickel base superalloys ASTROLOY and N18, allowing appliance of this process to engine parts : Inertia welding of superalloys leads to deap microstructural changes in the H.A.Z. which have been, as well as upset, correlated to process parameters, weld geometry and base material microstructure; a full mechanical testing of welds shown properties equivalent to base material ones up to 650 C except for fatigue crack growth behavior under specific conditions (T>600 C-hold time at maximum load) which is drastically reduced for in weld plane propagation. A significant improvement of this later property has been done through post-welding heat treatment and optimization of welding parameters. Last part of this paper summarize the main teachings gained, on the complete welding procedure, from welding of scale one parts. (orig.)

Estimation of snow pollution in the region of non-ferrous metallurgy enterprises by the neutron activation method

International Nuclear Information System (INIS)

Khatamov, Sh.; Khamidova, R.; Kist, A.A.

1980-01-01

Possibility of determination of more than 25 chemical elements in snow water selected in the region of non-ferrous metallurgy enterprises has been shown using the methods of neutron activation and γ-spectrometry of high resolution. Elements were determined from one sample by three-fold irradiation in the nuclear reactor depending on the half-life period and other nuclear activation parameters of the formed radioisotopes. The analysis of snow cover has revealed the character of pollution of surrounding medium and air basin by toxical elements

Contribution to the study of copper and copper-arsenic archaeo-metallurgy using light element analysis and experimental fusion; Contribution a l`etude de la paleometallurgie du cuivre et du cuivre-arsenic a partir de l`analyse des elements legers et de fusions experimentales

Energy Technology Data Exchange (ETDEWEB)

Papillon, F

1997-12-31

The objective of this study is to try a direct reconstruction from ancient artefacts of the elaboration technology used in the dawning copper metallurgy. This word is based on both the light elements analysis and the carry out of the principles of physical metallurgy. However the study of an archaeological artefact necessitates the use of non destructive methods. A main aspect of this work consists in developing the most adequate metallographic technique and the methods for the determination of oxygen and carbon by ion beam analysis. Additionally experimental melting of copper and copper arsenic alloys were carried out in laboratory, under various temperature and atmosphere conditions, and `on the field` in Archeodrome de Beaune, in order to reconstruct part of the prehistorical craftsmanship. The results of measurement are consistent with our general knowledge of oxido-reduction phenomena and the behaviour of copper and copper arsenic alloys s in agreement with the prediction of thermodynamics. The nuclear analysis of three ancient artefacts showed that the oxygen and carbon contents were closer to those of the Archeodrome than those of the laboratory. Further studies of the field should consider all parameters controlling the physical-chemistry of charcoal fire. (author) 96 refs.

Comparison of Depth of Anesthesia in Different Parts of Maxilla When Only Buccal Anesthesia Was Done for Maxillary Teeth Extraction

OpenAIRE

Isik, Kubilay; Kalayci, Abdullah; Durmus, Ercan

2011-01-01

Objective. Recently, some authors reported that maxillary teeth could be extracted without using palatal anesthesia, but they did not clearly specify the extracted teeth. This is important, because apparently the local anesthetic solution infiltrates the maxilla and achieves a sufficient anesthesia in the palatal side. Thus, thickness of the bone may affect the depth of anesthesia. The aim of this study was to compare the depth of anesthesia in different parts of the maxilla when only a bucca...

Processing of W-Cu functionally graded materials (FGM) through the powder metallurgy route: application as plasma facing components for ITER-like thermonuclear fusion reactor

International Nuclear Information System (INIS)

Raharijaona, J.J.

2009-11-01

The aim of this study was to study and optimize the sintering of W-Cu graded composition materials, for first wall of ITER-like thermonuclear reactor application. The graded composition in the material generates graded functional properties (Functionally Graded Materials - FGM). Rough thermomechanical calculations have shown the interest of W-Cu FGM to improve the lifetime of Plasma Facing Components (PFC). To process W-Cu FGM, powder metallurgy route was analyzed and optimized from W-CuO powder mixtures. The influence of oxide reduction on the sintering of powder mixtures was highlighted. An optimal heating treatment under He/H 2 atmosphere was determined. The sintering mechanisms were deduced from the analysis of the effect of the Cu-content. Sintering of W-Cu materials with a graded composition and grain size has revealed two liquid migration steps: i) capillary migration, after the Cu-melting and, ii) expulsion of liquid, at the end of sintering, from the dense part to the porous part, due to the continuation of W-skeleton sintering. These two steps were confirmed by a model based on capillary pressure calculation. In addition, thermal conductivity measurements were conducted on sintered parts and showed values which gradually increase with the Cu-content. Hardness tests on a polished cross-section in the bulk are consistent with the composition profiles obtained and the differential grain size. (author)

Wear mechanisms in powder metallurgy high speed steels matrix composites

International Nuclear Information System (INIS)

Gordo, E.; Martinez, M. A.; Torralba, J. M.; Jimenez, J. A.

2001-01-01

The development of metal matrix composites has a major interest for automotive and cutting tools industries since they possess better mechanical properties and wear resistance than corresponding base materials. One of the manufacturing methods for these materials includes processing by powder metallurgy techniques. in this case, blending of both, base material and reinforcement powders constitute the most important process in order to achieve a homogeneous distribution of second phase particles. in the present work, composite materials of M3/2 tool steel reinforced with 2.5,5 and 8 vol% of niobium carbide have been prepared. In order to ensure a homogeneous mix, powders of both materials were mixed by dry high-energy mechanical milling at 200 r.p.m. for 40 h. After a recovering annealing, two routes for consolidate were followed die pressing and vacuum sintering, and hot isostatic pressing (HIP). Pin-on-disc tests were carried out to evaluate wear behaviour in all the materials. Results show that ceramic particles additions improve wear resistance of base material. (Author) 9 refs

Microstructure characteristic for high temperature deformation of powder metallurgy Ti–47Al–2Cr–0.2Mo alloy

International Nuclear Information System (INIS)

Zhang, Dan-yang; Li, Hui-zhong; Liang, Xiao-peng; Wei, Zhong-wei; Liu, Yong

2014-01-01

Highlights: • With temperature increasing and strain rate decreasing, the β phase decreases. • With temperature increasing and strain rate decreasing, DRX grains increase. • The high temperature deformation mechanism of TiAl alloy was clearly. - Abstract: Hot compression tests of a powder metallurgy (P/M) Ti–47Al–2Cr–0.2Mo (at. pct) alloy were carried out on a Gleeble-3500 simulator at the temperatures ranging from 1000 °C to 1150 °C with low strain rates ranging from 1 × 10 −3 s −1 to 1 s −1 . Electron back scattered diffraction (EBSD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed to investigate the microstructure characteristic and nucleation mechanisms of dynamic recrystallization. The stress–strain curves show the typical characteristic of working hardening and flow softening. The working hardening is attributed to the dislocation movement. The flow softening is attributed to the dynamic recrystallization (DRX). The number of β phase decreases with increasing of deformation temperature and decreasing of strain rate. The ratio of dynamic recrystallization grain increases with the increasing of temperature and decreasing of strain rate. High temperature deformation mechanism of powder metallurgy Ti–47Al–2Cr–0.2Mo alloy mainly refers to twinning, dislocations motion, bending and reorientation of lamellae

Innovative technologies for powder metallurgy-based disk superalloys: Progress and proposal

Science.gov (United States)

Chong-Lin, Jia; Chang-Chun, Ge; Qing-Zhi, Yan

2016-02-01

Powder metallurgy (PM) superalloys are an important class of high temperature structural materials, key to the rotating components of aero engines. In the purview of the present challenges associated with PM superalloys, two novel approaches namely, powder preparation and the innovative spray-forming technique (for making turbine disk) are proposed and studied. Subsequently, advanced technologies like electrode-induction-melting gas atomization (EIGA), and spark-plasma discharge spheroidization (SPDS) are introduced, for ceramic-free superalloy powders. Presently, new processing routes are sought after for preparing finer and cleaner raw powders for disk superalloys. The progress of research in spray-formed PM superalloys is first summarized in detail. The spray-formed superalloy disks specifically exhibit excellent mechanical properties. This paper reviews the recent progress in innovative technologies for PM superalloys, with an emphasis on new ideas and approaches, central to the innovation driving techniques like powder processing and spray forming. Project supported by the National Natural Science Foundation of China (Grant Nos. 50974016 and 50071014).

Leading research on supermetals. Part 3. Small component material; Supermetal no sendo kenkyu. 3. Kogata buzai

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The control technology of nanostructure and amorphous structure for small components was studied by literature and patent survey. On nanostructured heat-resistant high-strength materials, a particle dispersion technology by MA method, up-grading technology of steel materials by controlled rolling and oxide metallurgy, and grain refinement technology by phase transformation were extracted. On nanostructured light-weight high-strength malarial, Al base alloy is promising from the viewpoint of resource and energy saving. On amorphous high environment resistant materials, the study on the corrosion resistance of Mo-Ta, Fe-Cr and Ni-Fe alloys is promising. On amorphous magnetic materials, the structure system with an amorphous formability higher than that of previous soft magnetic materials was found. R & D subjects for creating advanced amorphous and nanostructured bulk materials were extracted. Development of supporting technologies for material creation, formation and evaluation is necessary as well as the material design/control technology. 569 refs., 85 figs., 11 tabs.

Proceedings of the fifth national symposium on environment: focal theme environmental issues related to mining, milling and metallurgy

International Nuclear Information System (INIS)

Sastry, V.N.; Bapat, V.N.; Desai, M.V.M.

1996-02-01

The fifth National Symposium on Environment was held in Calcutta from February 28 to March 1, 1996. It focused on environmental issues related to mining, milling and metallurgy. Some of the topics covered are coal mining and related environmental issues, chromium mining and associated environmental problems, heavy metals especially nuclear materials and the environmental management strategies, arsenic contamination in water in West Bengal areas and radiological issues related to fertilizers and gypsum industries. Papers relevant to INIS are indexed separately. refs., figs., tabs

List of unclassified documents by the staff of Metallurgy Division, AERE Harwell from January 1972 to July 1977

International Nuclear Information System (INIS)

Wallis, V.

1977-11-01

This list constitutes unclassified material published or presented between January 1972 and July 1977 by the staff of Metallurgy Division. It covers reports, memoranda, bibliographies, articles in periodicals, conference papers, books, theses and patent specifications. It is planned to issue a list annually. The publications are listed under the following titles of the research teams concerned: fast reactor fuels, advanced reactor systems, fracture studies, structural materials, radiation effects, composite materials, high voltage microscope and metals fabrication, management and administration. (U.K.)

Corrosion resistant zirconium alloys prepared by powder metallurgy

International Nuclear Information System (INIS)

Wojeik, C.C.

1984-01-01

Pure zirconium and zirconium 2.5% niobium were prepared by powder metallurgy. The powders were prepared directly from sponge and consolidated by cold isostatic pressing and sintering. Hot isostatic pressing was also used to obtain full density after sintering. For pure zirconium the effects of particle size, compaction pressure, sintering temperature and purity were investigated. Fully densified zirconium and Zr-2.5%Nb exhibited tensile properties comparable to cast material at room temperature and 300 0 F (149 0 C). Pressed and sintered material having density of 94-99% had slightly lower tensile properties. Corrosion tests were performed in boiling 65% H/sub 2/SO/sub 4/, 70% HNO/sub 3/, 20% HCl and 20% HCl + 500 ppm FeCl/sub 3/ (a known pitting solution). For fully dense material the observed corrosion behavior was nearly equivalent to cast material. A slightly higher rate of attack was observed for samples which were only 94-99% dense. Welding tests were also performed on zirconium and Zr-2.5%Nb alloy. Unlike P/M titanium alloys, these materials had good weldability due to the lower content of volatile impurities in the powder. A slight amount of weld porosity was observed but joint efficiencies were always not 100%, even for 94-99% density samples. Several practical applications of the P/M processed material will be briefly described

Fracture behaviour of Cu-Al-Ni shape memory alloys obtained by powder metallurgy

International Nuclear Information System (INIS)

Rodriguez, P. P.; Perez-Saez, R. B.; Recarte, V.; San Juan, J.M.; Ruano, O. A.; No, M. L.

2001-01-01

Polycrystalline Cu-Al-Ni shape memory alloys have been scarcely employed for technological applications due to their high brittleness. The development of a new elaboration technique based on powder metallurgy has recently overcome this problem, through the improvement of the ductility of the produced alloys without affecting its shape memory properties. The fracture behaviour of an alloy obtained using the elaboration technique has been studied by means of Scanning Electron Microscopy and mechanical testing. The results show a ductile fracture with a maximum strain close to 13%, which is the best fracture behaviour obtained for Cu-Al-Ni polycrystals. The microstructure of such alloys ha been studied by means of Transmission Electron Microscopy, showing a poligonyzed structure in which martensite plated passing through the subboundaries easily. (Author) 19 refs

Cytotoxic and pro-oxidative effects of Imperata cylindrica aerial part ethyl acetate extract in colorectal cancer in vitro.

Science.gov (United States)

Kwok, Amy Ho Yan; Wang, Yan; Ho, Wing Shing

2016-05-15

Colorectal cancer (CRC) is the third most common cancer. Its global incidence and mortality have been on the rise. Recent strategy of therapies has involved the use of non-steroid anti-inflammatory drugs and cyclooxygenase-selective inhibitors. Aerial parts of Imperata cylindrical L. Raeusch (IMP) have been used as an anti-inflammatory agent in traditional Chinese medicine. Asarachidonate acid cascadeis often involved in inflammation-related malignancy and IMP is an anti-inflammatory agent, hence it is hypothesized that IMP aerial part ethyl acetate extract exerts cytotoxic effects on colorectal cancer cells in vitro. The HT-29 adenocarcinoma cell line was used to elucidate its pro-apoptotic activities. Flow cytometry and fluorescent microscopy were performed to assess cell cycle arrest and the accumulation of reactive oxygen species (ROS). The mRNA and hormone levels of arachidonate acid pathways were studied via quantitative reverse transcription PCR (qRT-PCR) and ELISA. The 50% growth inhibitory effect (GI50) of the IMP extract on HT-29 was measured with a value of 14.5 µg/ml. Immuno-blot and caspase-3/7 activity assay showed the pro-apoptotic effect of IMP on the activation of caspase cascade. G2/M arrest was observed via flow cytometry. The ROS activity was modulated by the IMP extraction a concentration-dependent manner in HT-29 cells. The IMP extract increased PGE2 and PGF2α levels qRT-PCR revealed that transcripts of rate-limiting PGE2- and PGF2α-biosynthetic enzymes - COX-1, mPGES1 and AKR1C3 were notably up-regulated. Among the prostanoid receptors, EP1 and FP transcripts were up-regulated while EP4 transcripts decreased. The findings suggest that the proliferative effect of PGE2, which is generally believed to associate with heightened DNA synthesis and cross-talk with MAPK pathways, is likely triggered by the pro-apoptotic or -oxidative effects exerted by IMP extract in HT-29 cells. Concurring with this notion, indomethacin (COX-1/2-inhibitor) was

Chemical Composition of Hexane Extract of Different Parts of Anthemis talyschensis and its Potential to Use in Sunscreen Products

Directory of Open Access Journals (Sweden)

Alireza Motavalizadehkakhky

2016-06-01

Full Text Available In this study, both the presence and concentration of some unsaturated compounds in hexane extracts of different parts of Anthemis talyschensis showing absorption at wavelength 280-450 nm were surveyed, with the view of possibly using extracts of this plant in new formulations of sunscreen creams. The hexane extracts of flower, leaf and stem of A. talyschensis, collected from Northwest Iran, were obtained using a Soxhlet apparatus. The fatty acids were derivatized to methyl esters and were determined by gas chromatography/flame ionization detector (GC/FID and gas chromatography/mass spectrometry (GC/MS systems. The chemical analysis resulted in identification of 14, 9 and 29 constituents, comprising about 99.5, 97.1 and 98.2% of the total constituents in hexane extracts of flower, leaf and stem, respectively. The main unsaturated constituents in the hexane extract of A. talyschensis flower were 9, 12-octadecadienoic acid, 9-octadecenoic acid and 6, 9, 12-octadecatrienoic acid; while the leaf's extract contained 9, 12-octadecadienoic acid and 9-octadecenoic acid; no unsaturated compounds were detected in the stem. The ratios of unsaturated fatty acid /saturated fatty acid were 13.6, 9.3 and 0 in extracts of the flower, leaf and stem, respectively, but the total amounts in the leaf were much greater. It can be concluded the leaf extract is more likely to be suitable for producing sunscreens creams than others.

9th Mining and metallurgy international congress, Leon, 24-28 May 1994

International Nuclear Information System (INIS)

1994-01-01

The 9th Mining and Metallurgy International Congress had 201 communications. These was articulated into 4th areas: 1.- Geological resources management and profit: 1.1- Geological and mining research on geologic resources. 1.2.- Non energetic mineral resources exploitation. 1.3- Hydro-geologic and geothermia resources. 1.4- Geologic resources and planning. 2.- Energy: 2.1.- Energetic mining.- 2.2 Oil and gas. 2.3.- Electricity production and distribution. 2.4.- Coal clean technologies. 2.5.- Energetic management. 3.- Material engineering: 3.1.- Minerallurgia and metallurgic processes. 3.2- Industrial minerals and ornamental 10cks. 3.3 .- Building materials. 3.4 Advanced technology materials. 4.- Environmental and territorial engineering in basic industry. 4.1.-Valuation of environmental impacts. 4.2.- Restoration engineering in mining. 4.3.- Effluent and residue engineering. 4.4.- Environmental management and clean technologies 4.5.- Natural and technological risks

A powder metallurgy austenitic stainless steel for application at very low temperatures

CERN Document Server

Sgobba, Stefano; Liimatainen, J; Kumpula, M

2000-01-01

The Large Hadron Collider to be built at CERN will require 1232 superconducting dipole magnets operating at 1.9 K. By virtue of their mechanical properties, weldability and improved austenite stability, nitrogen enriched austenitic stainless steels have been chosen as the material for several of the structural components of these magnets. Powder Metallurgy (PM) could represent an attractive production technique for components of complex shape for which dimension tolerances, dimensional stability, weldability are key issues during fabrication, and mechanical properties, ductility and leak tightness have to be guaranteed during operation. PM Hot Isostatic Pressed test plates and prototype components of 316LN-type grade have been produced by Santasalo Powdermet Oy. They have been fully characterized and mechanically tested down to 4.2 K at CERN. The fine grained structure, the absence of residual stresses, the full isotropy of mechanical properties associated to the low level of Prior Particle Boundaries oxides ...

Risk factors causing evolvement of alimentary-dependent diseases in specific groups of workers employed at metallurgy production and prevention meausres development

Directory of Open Access Journals (Sweden)

Yu.V. Danilova

2017-03-01

Full Text Available The article gives the results of hygienic and epidemiologic research of morbidity, nutrition structure, food stuffs safety, working conditions, and actual nutrition of workers employed at metallurgy productions. The research was carried out at "Magnitogorskiy metallurgy plant" PLC. 1208 steel workers and founders made up the main group. Average age of research participants amounted to 40.0 ± 0.75. The sampling was representative. We studied actual nutrition over 2010–2015 via analyzing food consumption frequency and applying extended base of food stuffs chemical structure and analyzing menus with lists of dishes offered for an organized group nutrition. We assessed both qualitative and quantitative parameters, including consumption of basic nutrients, energy, irreplaceable amino acids, lipids, vitamins, dietary fiber, essential and conditionally essential microbiological elements (60 nutrients totally, allowing for losses on a product peeling, edible contents, and other losses occurring at various treatments during cooking. We also assessed nutrition regime and other nutrition features. We detected that ratio between proteins, fats and carbohydrates was the evidence of mostly fat nutrition type. Workers were found to consume insufficient quantity of certain vitamins (A, D, and folic acid and biological elements (calcium, but they instead consumed excessive quantities of saturated fats and common salt. It is shown that actual nutrition of specific workers' groups at metallurgy production is not rational, imbalanced, and doesn't satisfy body needs causing risks of nutrition state shifts and alimentary-dependent diseases evolvement. Alimentary-dependent diseases on average amounted to 21.6 % in the total morbidity structure in 2010–2015. 10.0 % of all diseases with temporary working disability are diseases determined by mostly nutrition factor. Epidemiologic analysis of morbidity comprising diseases related to non-rational nutrition enabled us

The Effectiveness of a NiCrY-Coating on a Powder Metallurgy Disk Superalloy

Science.gov (United States)

Gabb, Timothy P.; Miller, Robert A.; Nesbitt, James A.; Draper, Susan L.; Rogers, Richard B.; Telesman, Jack

2018-01-01

Protective ductile coatings could be necessary to mitigate oxidation and corrosion attack on superalloy disks in some turbine engine applications. However, the effects of coatings on fatigue life of the disk during service are an important concern. The objective of this study was to investigate how such a coating could perform after varied post-coating processing. Cylindrical gage fatigue specimens of powder metallurgy-processed disk superalloy LSHR were coated with a NiCrY coating, shot peened, preparation treated, exposed, and then subjected to fatigue at high temperature. The effects of varied shot peening, preparation treatment, and exposures on fatigue life with and without the coating were compared. Each of these variables and several of their interactions significantly influenced fatigue life.

Proceedings of papers. 3. Balkan Metallurgical Conference; Kniga na trudovi. 3-ta Balkanska konferencija na metalurzite

Energy Technology Data Exchange (ETDEWEB)

Mickovski, Jovan [Faculty of Technology and Metallurgy, St. ' Cyril and Methodius' University, Skopje (Macedonia, The Former Yugoslav Republic of)

2003-07-01

This Conference aims to be a central event in the metallurgy research of Balkan, fulfilling the goals to present the most outstanding relevant developments in modern metallurgy; to inspire high standards of excellence in pure and applied metallurgy research; to attract outstanding scientists to present central lectures on modem metallurgical research, and on the challenges imposed by the needs of society; to inspire the young generation of metallurgists in Balkan and other countries. Following these lines, the 3. Balkan Conference on Metallurgy will provide a unique opportunity for academic and industrial metallurgists from the Balkan countries and wider, to exchange ideas, expertise, and experience on topics related to the theme of the Conference - Balkan Metallurgy in Search for New Ways of Development. The aim of the organizers was to bring together distinguished experts, not only to present their work, but also to discuss the major scientific and technological challenges facing metallurgy in this millennium.The 6 sections of the conference were entitled: Section A: Extractive metallurgy; Section B: Physical metallurgy and materials science - ferrous metals and non ferrous metals; Section C: Management, maintenance control and optimization of metallurgical processes; Section D: New technologies and techniques; Section E: Refractory and powder; Section F: Corrosion and protection of metals. Papers relevant to INIS are indexed separately.

Proceedings of papers. 3. Balkan Metallurgical Conference

International Nuclear Information System (INIS)

Mickovski, Jovan

2003-01-01

This Conference aims to be a central event in the metallurgy research of Balkan, fulfilling the goals to present the most outstanding relevant developments in modern metallurgy; to inspire high standards of excellence in pure and applied metallurgy research; to attract outstanding scientists to present central lectures on modem metallurgical research, and on the challenges imposed by the needs of society; to inspire the young generation of metallurgists in Balkan and other countries. Following these lines, the 3. Balkan Conference on Metallurgy will provide a unique opportunity for academic and industrial metallurgists from the Balkan countries and wider, to exchange ideas, expertise, and experience on topics related to the theme of the Conference - Balkan Metallurgy in Search for New Ways of Development. The aim of the organizers was to bring together distinguished experts, not only to present their work, but also to discuss the major scientific and technological challenges facing metallurgy in this millennium.The 6 sections of the conference were entitled: Section A: Extractive metallurgy; Section B: Physical metallurgy and materials science - ferrous metals and non ferrous metals; Section C: Management, maintenance control and optimization of metallurgical processes; Section D: New technologies and techniques; Section E: Refractory and powder; Section F: Corrosion and protection of metals. Papers relevant to INIS are indexed separately

Box-Behnken factorial design to obtain a phenolic-rich extract from the aerial parts of Chelidonium majus L.

Science.gov (United States)

Grosso, Clara; Ferreres, Federico; Gil-Izquierdo, Angel; Valentão, Patrícia; Sampaio, Maria; Lima, Júlio; Andrade, Paula B

2014-12-01

A Box-Behnken design (BBD) was developed to study the influence of four parameters (X1: % methanol; X2: extraction time; X3: extraction temperature; X4: solid/solvent ratio) on two responses, namely extraction yield and phenolics content of the aerial parts of Chelidonium majus L. The model presented a good fit to the experimental results for the extraction yield, being significantly influenced by X1 and X4. On the other hand a parameter reduction was necessary to run the model for phenolics content, showing that only X1 and X2 had great influence on the response. Two best extraction conditions were defined: X1=76.8% MeOH, X2=150.0 min, X3=60.0°C and X4=1:100 and X1=69.2%, X2=150 min, X3=42.5°C and X4=1:100. Moreover, the HPLC-DAD-ESI/MS(n) analysis conducted with the center point sample revealed the presence of 15 alkaloids and 15 phenolic compounds, from which the 9 flavonoids and 3 hydroxycinnamic acids are described for the first time. Only phenolic compounds were quantified by a validated HPLC-DAD method, the pair quercetin-3-O-rutinoside+quercetin-3-O-glucoside dominating all the 29 extracts. This study is of great importance for future works that seek to apply the phenolic profile to the quality control of C. majus samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Obtainment of the alloy Cu13Al4Ni using processed by powder metallurgy; Obtencao da liga Cu13Al4Ni via metalurgia do po

Energy Technology Data Exchange (ETDEWEB)

Grossi, L.J.; Damasceno, N.; Muterlle, P.V., E-mail: larajgrossi@yahoo.com.br [Universidade de Brasilia (UnB), Brasilia, DF (Brazil). Departamento de Engenharia Mecanica

2016-07-01

The powder metallurgy is a technique environmentally advantageous that allows the production of many pieces, with a good superficial finishing and dimensional tolerance. For the production of pieces using technique, basics steps are carried out, as the characterization of powders, the mixing and homogenization, compacting and sintering. In this context, this work has as objective the obtainment of the Cu13Al4Ni alloy via powder metallurgy. For this, was made a high energy milling for 2, 4 and 8 hours. Then, the milled powder was compacted and posteriorly, sintered in an oven with controlled atmosphere. It was observed that the milling time affects directly in sintering of the pieces. The best results obtained were for the samples that were milled for 4 hours. This samples have showed 21, 52% of porosity and 6,382 g/cm³ of the density of sintered. (author)

Antifungal Activity of the Crude Extracts and Extracted Phenols from Gametophytes and Sporophytes of Two Species of Adiantum

Directory of Open Access Journals (Sweden)

Piyali Guha (Ghosh

2005-12-01

Full Text Available The water extracts and extracted phenols from gametophytes and different parts of sporophytes of the two ferns, Adiantum capillus-veneris L. and Adiantum lunulatum Burm. f., used as folkloric medicines in India, China, Tibet, America, Philippines and Italy, were investigated for their antifungal activity against Aspergillus niger and Rhizopus stolonifer. Both crude extracts and extracted phenols of gametophytes and different parts of sporophytes of both fern species were found to be bioactive against the fungal strains. Antifungal activity was found to be higher in gametophytes than different parts of sporophytes. Among the different parts of sporophyte, immature pinnule possesses highest fungistatic property. Adiantum capillus-veneris was found a better antifungal agent than Adiantum lunulatum.

Power-law creep of powder-metallurgy grade molybdenum sheet

International Nuclear Information System (INIS)

Ciulik, J.; Taleff, E.M.

2007-01-01

Creep behavior of commercial-purity, powder-metallurgy grade molybdenum (Mo) sheet has been investigated at temperatures between 1300 and 1600 deg. C (0.56-0.63 T m ) using tensile testing at controlled strain rates. Strain-rate-change tests were performed at constant-temperatures over true-strain rates from 1.0 x 10 -6 to 5.0 x 10 -4 s -1 . Results agree with previously published data indicating that Mo follows power-law creep with a stress exponent of about 5; however, the present results address a temperature range not previously documented. The activation energy for creep was determined to be 240 kJ/mol within this temperature range, which is lower than previously published values and approximately half the value reported for self-diffusion, indicating that diffusion mechanisms faster than lattice diffusion are active. It is shown that Mo creep data from a variety of investigations converge closely to a single line on a master plot of strain rate normalized using an activation energy of 240 kJ/mol when plotted against stress normalized by the temperature-dependent elastic modulus. This activation energy for creep is attributed to an effective diffusivity that fits the creep data obtained during this study as well as from previously published creep data from commercial-purity molybdenum

Comparison Study on Additive Manufacturing (AM) and Powder Metallurgy (PM) AlSi10Mg Alloys

Science.gov (United States)

Chen, B.; Moon, S. K.; Yao, X.; Bi, G.; Shen, J.; Umeda, J.; Kondoh, K.

2018-02-01

The microstructural and mechanical properties of AlSi10Mg alloys fabricated by additive manufacturing (AM) and powder metallurgy (PM) routes were investigated and compared. The microstructures were examined by scanning electron microscopy assisted with electron-dispersive spectroscopy. The crystalline features were studied by x-ray diffraction and electron backscatter diffraction. Room-temperature tensile tests and Vickers hardness measurements were performed to characterize the mechanical properties. It was found that the AM alloy had coarser Al grains but much finer Si precipitates compared with the PM alloy. Consequently, the AM alloy showed more than 100% increment in strength and hardness compared with the PM alloy due to the presence of ultrafine forms of Si, while exhibiting moderate ductility.

[CHEMICAL AIR POLLUTION OF THE OCCUPATIONAL ENVIRONMENT AS A FACTOR FOR PROFESSIONAL RISK FOR WORKERS OF MAIN OCCUPATIONS IN THE COPPER AND NICKEL METALLURGY].

Science.gov (United States)

Lipatov, G Ia; Adrianovskiĭ, V I; Gogoleva, O I

2015-01-01

There are presented the results of hygienic researches of the harmful substances content in the air of the working area ofthe copper and nickel metallurgy. Sulfur-containing gases (primarily sulfur dioxide), to the effects of which there are exposed workers of drying, smelting, converter conversion, are shown to play a leading role among professional factors.

[Evaluation and prognosis of occupational risk in workers of nonferrous metallurgy enterprises].

Science.gov (United States)

Shliapnikov, D M; Kostarev, V G

2014-01-01

The article deals with results of a priori and a posteriori evaluation of occupational risk for workers' health. Categories of a priori occupational risk for workers are estimated as high to very high (intolerable) risk. Findings are that work conditions in nonferrous metallurgy workshop result in upper respiratory tract diseases (medium degree of occupational conditionality). Increased prevalence of such diseases among the workers is connected with length of service. The authors revealed priority factors for occupationally conditioned diseases. A promising approach in occupational medicine is creation of methods to evaluate and forecast occupational risk, that enable to specify goal parameters for prophylactic measures. For example, modelling the risk of occupationally conditioned diseases via changes in exposure to occupational factor and length of service proved that decrease of chemical concentrations in air of workplace to maximally allowable ones lowers risk of respiratory diseases from 14 to 6 cases per year, for length of service of 5 years and population risk.

Copper-carbon and aluminum-carbon composites fabricated by powder metallurgy processes

International Nuclear Information System (INIS)

Silvain, Jean-François; Veillère, Amélie; Lu, Yongfeng

2014-01-01

The increase in both power and packing densities in power electronic devices has led to an increase in the market demand for effective heat-dissipating materials, with high thermal conductivity and thermal- expansion coefficient compatible with chip materials still ensuring the reliability of the power modules. In this context, metal matrix composites: carbon fibers and diamond-reinforced copper and aluminum matrix composites among them are considered very promising as a next generation of thermal-management materials in power electronic packages. These composites exhibit enhanced thermal properties compared to pure copper combined with lower density. This article presents the fabrication techniques of copper/carbon fibers and copper/diamond and aluminum/carbon fibers composite films by powder metallurgy and hot pressing. The thermal analyses clearly indicate that interfacial treatments are required in these composites to achieve high thermomechanical properties. Interfaces (through novel chemical and processing methods), when selected carefully and processed properly will form the right chemical/mechanical link between metal and carbon, enhancing all the desired thermal properties while minimizing the deleterious effect.

Modeling of wear behavior of Al/B_4C composites produced by powder metallurgy

International Nuclear Information System (INIS)

Sahin, Ismail; Bektas, Asli; Guel, Ferhat; Cinci, Hanifi

2017-01-01

Wear characteristics of composites, Al matrix reinforced with B_4C particles percentages of 5, 10,15 and 20 produced by the powder metallurgy method were studied in this study. For this purpose, a mixture of Al and B_4C powders were pressed under 650 MPa pressure and then sintered at 635 C. The analysis of hardness, density and microstructure was performed. The produced samples were worn using a pin-on-disk abrasion device under 10, 20 and 30 N load through 500, 800 and 1200 mesh SiC abrasive papers. The obtained wear values were implemented in an artificial neural network (ANN) model having three inputs and one output using feed forward backpropagation Levenberg-Marquardt algorithm. Thus, the optimum wear conditions and hardness values were determined.

Development of fully dense and high performance powder metallurgy HSLA steel using HIP method

Science.gov (United States)

Liu, Wensheng; Pang, Xinkuan; Ma, Yunzhu; Cai, Qingshan; Zhu, Wentan; Liang, Chaoping

2018-05-01

In order to solve the problem that the mechanical properties of powder metallurgy (P/M) steels are much lower than those of traditional cast steels with the same composition due to their porosity, a high–strength–low–alloy (HSLA) steel with fully dense and excellent mechanical properties was fabricated through hot isostatic pressing (HIP) using gas–atomized powders. The granular structure in the P/M HIPed steel composed of bainitic ferrite and martensite–austenite (M–A) islands is obtained without the need of any rapid cooling. The P/M HIPed steel exhibit a combination of tensile strength and ductility that surpasses that of conventional cast steel and P/M sintered steel, confirming the feasibility of fabricating high performance P/M steel through appropriate microstructural control and manufacture process.

Bioactivity of the extracts and isolation of lignans and a sesquiterpene from the aerial parts of Centaurea pamphylica (Asteraceae

Directory of Open Access Journals (Sweden)

Shoeb M.

2007-06-01

Full Text Available Centaurea pamphylica Boiss. & Heldr. (Family: Asteraceae, commonly known as ‘pamphylia daisy', is a Turkish endemic species of the genus Centaurea that comprises ca. 500 species, many of which have been used as traditional medicines.  The n-hexane, dichloromethane (DCM and methanol (MeOH extracts of the aerial parts of C. pamphylica were assessed for antioxidant activity and general toxicity using, respectively, the 2,2-diphenyl-1-picrylhydrazyl (DPPH, and the brine shrimp lethality assays. The reversed-phase preparative HPLC and PTLC were used to isolate compounds from the extracts.  The structures of these compounds [1-4] were elucidated by spectroscopic means, and also by direct comparison with the respective published data.  Both the DCM and the MeOH extract showed significant levels of antioxidant activities with the RC50 values of 72.6 x 10-2 and 47.3 ´ 10-2 mg/mL, respectively. The MeOH extract exhibited low levels of toxicity towards brine shrimps (LD50 = 125.0 ´ 10-2 mg/mL. Three major bioactive components of the MeOH extract were matairesinoside [1], arctiin [2] and matairesinol [3]. An eudesmane-type sesquiterpene, pterodontriol [4], was also isolated from the DCM extract.  Since reactive oxygen species are important contributors to various ailments, the antioxidant properties of the extracts as well as the isolated compounds may be of medicinal significance. This is the first report on the occurrence of 1-4 in C. pamphylica, and 4 in the genus Centaurea.  

Investigation of hydrostatic extrusion and other deformation modes for the fabrication of multifilamentary niobium--tin superconductors by a powder metallurgy approach

International Nuclear Information System (INIS)

MacLeod, G.E.

1977-06-01

Various aspects of a powder metallurgy approach to fabricate filamentary niobium-tin superconducting wire were investigated. Difficulties occurred due to lack of complete tin infiltration of the sintered niobium rod, formation of intermetallics during infiltration, and both cladding and core fracture during mechanical reduction. The influence of sintering time, infiltration temperature, and deformation mode was investigated. Progress is reported on the clarification of the role of several of the important process parameters

Optimization of the Hot Forging Processing Parameters for Powder Metallurgy Fe-Cu-C Connecting Rods Based on Finite Element Simulation

Science.gov (United States)

Li, Fengxian; Yi, Jianhong; Eckert, Jürgen

2017-12-01

Powder forged connecting rods have the problem of non-uniform density distributions because of their complex geometric shape. The densification behaviors of powder metallurgy (PM) connecting rod preforms during hot forging processes play a significant role in optimizing the connecting rod quality. The deformation behaviors of a connecting rod preform, a Fe-3Cu-0.5C (wt pct) alloy compacted and sintered by the powder metallurgy route (PM Fe-Cu-C), were investigated using the finite element method, while damage and friction behaviors of the material were considered in the complicated forging process. The calculated results agree well with the experimental results. The relationship between the processing parameters of hot forging and the relative density of the connecting rod was revealed. The results showed that the relative density of the hot forged connecting rod at the central shank changed significantly compared with the relative density at the big end and at the small end. Moreover, the relative density of the connecting rod was sensitive to the processing parameters such as the forging velocity and the initial density of the preform. The optimum forging processing parameters were determined and presented by using an orthogonal design method. This work suggests that the processing parameters can be optimized to prepare a connecting rod with uniform density distribution and can help to better meet the requirements of the connecting rod industry.

Antidepressant and anxiolytic activity of Lavandula officinalis aerial parts hydroalcoholic extract in scopolamine-treated rats.

Science.gov (United States)

Rahmati, Batool; Kiasalari, Zahra; Roghani, Mehrdad; Khalili, Mohsen; Ansari, Fariba

2017-12-01

Anxiety and depression are common in Alzheimer's disease (AD). Despite some evidence, it is difficult to confirm Lavandula officinalis Chaix ex Vill (Lamiaceae) as an anxiolytic and antidepressant drug. The effects of L. officinalis extract were studied in scopolamine-induced memory impairment, anxiety and depression-like behaviour. Male NMRI rats were divided into control, scopolamine alone-treated group received scopolamine (0.1 mg/kg) intraperitoneally (i.p.), daily and 30 min prior to performing behavioural testing on test day, for 12 continuous days and extract pretreated groups received aerial parts hydro alcoholic extract (i.p.) (100, 200 and 400 mg/kg), 30 min before each scopolamine injection. Memory impairment was assessed by Y-maze task, while, elevated plus maze and forced swimming test were used to measure anxiolytic and antidepressive-like activity. Spontaneous alternation percentage in Y maze is reduced by scopolamine (36.42 ± 2.60) (p ≤ 0.001), whereas lavender (200 and 400 mg/kg) enhanced it (83.12 ± 5.20 and 95 ± 11.08, respectively) (p ≤ 0.05). Also, lavender pretreatment in 200 and 400 mg/kg enhanced time spent on the open arms (15.4 ± 3.37 and 32.1 ± 3.46, respectively) (p ≤ 0.001). On the contrary, while immobility time was enhanced by scopolamine (296 ± 4.70), 100, 200 and 400 mg/kg lavender reduced it (193.88 ± 22.42, 73.3 ± 8.25 and 35.2 ± 4.22, respectively) in a dose-dependent manner (p ≤ 0.001). Lavender extracts improved scopolamine-induced memory impairment and also reduced anxiety and depression-like behaviour in a dose-dependent manner.

Report 1986/1987. Department of Nuclear Engineering and Applied Research

International Nuclear Information System (INIS)

1989-01-01

The objective of the Department of Applied Research is to carry out research on fields of physics, materials sciences, chemistry and engineering. Some branches of research can be mentioned: high Tc superconductors, hydrogen storage in metallic hydrides, extractive metallurgy of strategic minerals and others. In the first case, both the Development Division and the Thermodynamics group in the Metallurgy Division, have actively participated [es

30 CFR 947.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 947.702 Section 947.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

30 CFR 933.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 933.702 Section 933.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

30 CFR 939.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 939.702 Section 939.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

30 CFR 903.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 903.702 Section 903.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...

30 CFR 912.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 912.702 Section 912.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...

30 CFR 937.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 937.702 Section 937.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...

30 CFR 921.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 921.702 Section 921.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of the chapter, Exemption for Coal Extraction Incidental to the Extraction of...

30 CFR 905.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 905.702 Section 905.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

30 CFR 942.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 942.702 Section 942.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...

30 CFR 910.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 910.702 Section 910.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...

30 CFR 922.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 922.702 Section 922.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of Other...

30 CFR 941.702 - Exemption for coal extraction incidental to the extraction of other minerals.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Exemption for coal extraction incidental to the extraction of other minerals. 941.702 Section 941.702 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION... other minerals. Part 702 of this chapter, Exemption for Coal Extraction Incidental to the Extraction of...

New radiation technologies and methods for control of technological processes in metallurgy

International Nuclear Information System (INIS)

Zaykin, Yu.

1996-01-01

Radiation Technology of Metal and Ceramic Production with Enhanced Service Properties. Based on application of radiation technique in powder metallurgy the new technology for obtaining metals, alloys and ceramic materials with high service properties is worked out. Radiation processing of powder materials at the certain stage of the process leads to profound structure alterations at all further stages and eventually effects the properties of the resulting product. Theoretical calculation and experimental studies of electron-positron annihilation in powder-pressed samples showed that irradiation caused powder particles surface state changes favorable for further sintering and crystallization processes development. It is shown that irradiation of metal powders and powder-pressed samples by high energy electrons is technologically most efficient. The right choice of the type-and the mode of the radiation processing makes it possible to obtain metals, alloys and ceramic materials (Mo,Fe, W, Al, Ni, Cu, stainless steels, ceramics, etc.) with homogeneous structure and stable enhanced service properties. The project on radiation technology application to powder metallurgy represented by a group of authors was awarded with the diploma and the gold medal at the 22 International Exhibition of Inventions (Geneva, 1994). New Technologic Opportunities of the Chromium-Nickel Alloys Processing To obtain the required phase-structure state special methods of the chromium-nickel alloy processing for sensitive elastic devices production were worked out combining plastic deformation, thermal and radiation processing. It is shown that h-gbb phase transfer not observed before is possible in extremely non-equilibrium conditions under electron irradiation. It is established that the complex reaction of recrystallization and gb-phase deposition proceeds under electron irradiation at the room temperature when the certain threshold plastic deformation degree is reached that leads to the same

The competitiveness of metallurgy and metal products industry in Spain; La competitividad de las industrias metalurgica y de productos metalicos en Espana

Energy Technology Data Exchange (ETDEWEB)

Mateos Torres, C.

2012-07-01

This article analyzes the competitiveness of metallurgy and manufacture of metal products sectors, in which the Industrial Observatory of the Metal Sector has studied the key factors of innovation for competitiveness. It includes a reference to the competitive situation of the Spanish iron and steel industry. Furthermore, the investments carried out by both sectors under the Competitiveness Promotion Programme for Strategic Industrial Sectors during the years 2009-2011 are analyzed. (Author)

A comparative study of Averrhoabilimbi extraction method

Science.gov (United States)

Zulhaimi, H. I.; Rosli, I. R.; Kasim, K. F.; Akmal, H. Muhammad; Nuradibah, M. A.; Sam, S. T.

2017-09-01

In recent year, bioactive compound in plant has become a limelight in the food and pharmaceutical market, leading to research interest to implement effective technologies for extracting bioactive substance. Therefore, this study is focusing on extraction of Averrhoabilimbi by different extraction technique namely, maceration and ultrasound-assisted extraction. Fewplant partsof Averrhoabilimbiweretaken as extraction samples which are fruits, leaves and twig. Different solvents such as methanol, ethanol and distilled water were utilized in the process. Fruit extractsresult in highest extraction yield compared to other plant parts. Ethanol and distilled water have significant role compared to methanol in all parts and both extraction technique. The result also shows that ultrasound-assisted extraction gave comparable result with maceration. Besides, the shorter period on extraction process gives useful in term of implementation to industries.

Synthesis of silver nanoparticle using Portulaca oleracea L. extracts

Directory of Open Access Journals (Sweden)

Shahbazi Nafeseh

2013-09-01

Full Text Available   Objective(s: To evaluate the influences of aqueous extracts of plant parts (stem, leaves, and root of Portulaca oleracea L. on bioformation of silver nanoparticles (AgNPs.   Materials and Methods: Synthesis of silver nanoparticles by different plant part extracts of Portulaca oleracea L. was carried out and formation of nanoparticles were confirmed and evaluated using UV-Visible spectroscopy and AFM. Results: The plant extracts exposed with silver nitrate showed gradual change in color of the extract from yellow to dark brown. Different silver nanoperticles were formed using extracts of different plant parts. Conclusion: It seems that the plant parts differ in their ability to act as a reducing and capping agent.

Modelling the liquid-liquid extraction of nitric acid and lanthanide nitrates by tributylphosphate. Study of the influence of the aqueous phase composition on the selectivity of rare earth separation

International Nuclear Information System (INIS)

Mokili, Bandombele

1992-01-01

This research thesis reports the application of advances in the modelling of liquid-liquid extraction to a quantitative processing of the selectivity of separations. It is here applied to the extraction-based separation of lanthanide nitrates by using the tributylphosphate (TBP) in nitric environment as this system is interesting for industrial applications in hydro-metallurgy of rare earths as well as in the processing of irradiated nuclear fuels. Experimental data are acquired and then used in the Mikulin-Sergievskii-Dannus model. Complete modelling is thus obtained which allowed the complex problem of extraction of nitric acid and of lanthanide to be addressed, and the existence of a hybrid solvate to be supported. A mathematical expression of the separation factor of two lanthanides is proposed and used to highlight its influencing parameters, i.e. water activity in the aqueous phase, and the rate of the effective extraction constants of the two elements to be separated. Experimental observations are thus interpreted. The selection of optimal separation conditions is thus justified, and, in some cases, the system selectivity can be predicted [fr

Emissions from pre-Hispanic metallurgy in the South American atmosphere.

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François De Vleeschouwer

Full Text Available Metallurgical activities have been undertaken in northern South America (NSA for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

Emissions from pre-Hispanic metallurgy in the South American atmosphere.

Science.gov (United States)

De Vleeschouwer, François; Vanneste, Heleen; Mauquoy, Dmitri; Piotrowska, Natalia; Torrejón, Fernando; Roland, Thomas; Stein, Ariel; Le Roux, Gaël

2014-01-01

Metallurgical activities have been undertaken in northern South America (NSA) for millennia. However, it is still unknown how far atmospheric emissions from these activities have been transported. Since the timing of metallurgical activities is currently estimated from scarce archaeological discoveries, the availability of reliable and continuous records to refine the timing of past metal deposition in South America is essential, as it provides an alternative to discontinuous archives, as well as evidence for global trace metal transport. We show in a peat record from Tierra del Fuego that anthropogenic metals likely have been emitted into the atmosphere and transported from NSA to southern South America (SSA) over the last 4200 yrs. These findings are supported by modern time back-trajectories from NSA to SSA. We further show that apparent anthropogenic Cu and Sb emissions predate any archaeological evidence for metallurgical activities. Lead and Sn were also emitted into the atmosphere as by-products of Inca and Spanish metallurgy, whereas local coal-gold rushes and the industrial revolution contributed to local contamination. We suggest that the onset of pre-Hispanic metallurgical activities is earlier than previously reported from archaeological records and that atmospheric emissions of metals were transported from NSA to SSA.

Annual Report on Scientific Activities in 1997 of Department of Physics and Nuclear Techniques, Academy of Mining and Metallurgy, Cracow

International Nuclear Information System (INIS)

Wolny, J.; Olszynska, E.

1998-01-01

The Annual Report 1997 is the review of scientific activities of the Department of Nuclear Physics and Techniques (DNPT) of the Academy of Mining and Metallurgy, Cracow. The studies connected with: radiometric analysis, nuclear electronics, solid state physics, elementary particle and detectors, medical physics, physics of environment, theoretical physics, nuclear geophysics, energetic problems, industrial radiometry and tracer techniques have been broadly presented. The fill list of works being published and presented at scientific conferences in 1997 by the staff of DNPT are also included

Production of a low young modulus titanium alloy by powder metallurgy

Directory of Open Access Journals (Sweden)

Dalcy Roberto dos Santos

2005-12-01

Full Text Available Titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. A blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. The process employs hydride-dehydride (HDH powders as raw material. In this work, results of the Ti-35Nb alloy sintering are presented. This alloy due to its lower modulus of elasticity and high biocompatibility is a promising candidate for aerospace and medical use. Samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by isochronal sintering between 900 up to 1600 °C, in vacuum. Sintering behavior was studied by means of microscopy and density. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. Samples sintered at high temperatures display a fine plate-like alpha structure and intergranular beta. A few remaining pores are still found and density above 90% for specimens sintered in temperatures over 1500 °C is reached.

Titanium nitride deposition in titanium implant alloys produced by powder metallurgy

International Nuclear Information System (INIS)

Henriques, V.A.R.; Cairo, C.A.A.; Faria, J.; Lemos, T.G.; Galvani, E.T.

2009-01-01

Titanium nitride (TiN) is an extremely hard material, often used as a coating on titanium alloy, steel, carbide, and aluminum components to improve wear resistance. Electron Beam Physical Vapor Deposition (EB-PVD) is a form of deposition in which a target anode is bombarded with an electron beam given off by a charged tungsten filament under high vacuum, producing a thin film in a substrate. In this work are presented results of TiN deposition in targets and substrates of Ti (C.P.) and Ti- 13 Nb- 13 Zr obtained by powder metallurgy. Samples were produced by mixing of hydride metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering between 900°C up to 1400 °C, in vacuum. The deposition was carried out under nitrogen atmosphere. Sintered samples were characterized for phase composition, microstructure and microhardness by X-ray diffraction, scanning electron microscopy and Vickers indentation, respectively. It was shown that the samples were sintered to high densities and presented homogeneous microstructure, with ideal characteristics for an adequate deposition and adherence. The film layer presented a continuous structure with 15μm. (author)

Physical Protection Study of the Radio metallurgy Installation Using SAVIComputer Program

International Nuclear Information System (INIS)

Pinitoyo, Andreas

2000-01-01

Based on IAEA Recommendation on INFCIR/225/Rev.3 (The Physical Protectionof Nuclear Material), a nuclear installation shall have physical protectionsystem for protection or being secure on sabotage activities in theinstallation and thieve of nuclear materials. The recommendation states therequirements for physical protection of nuclear materials usage, transit andstorage. Radio metallurgy Installation of the Fuel Element and ReprocessingDevelopment Center (BATAN) at Serpong is a nuclear installation for researchon post irradiation of high radioactive spent fuel element, its processingand storage. The installation has risk on threat of a sabotage, which isdominant than thieve. The RMI building was designed and constructed ofphysical protection components and have been integrated with the BATAN Safetyand Security System and the Security Guards functions to be PhysicalProtection System for the RMI. By using the SAVI Computer Program with inputdata from the existing standards, assumptions for detection possibility,delay and response, that will result the probability of interruptions of theworst adversary paths PI = 0.1. These mean that the physical protectionsystems of the RMI shall be upgraded and improved in order to be reliable orbetter if the most of paths to the target PI = 1.0. (author)

Separating and recycling metals from mixed metallic particles of crushed electronic wastes by vacuum metallurgy.

Science.gov (United States)

Zhan, Lu; Xu, Zhenming

2009-09-15

During the treatment of electronic wastes, a crushing process is usually used to strip metals from various base plates. Several methods have been applied to separate metals from nonmetals. However, mixed metallic particles obtained from these processes are still a mixture of various metals, including some toxic heavy metals such as lead and cadmium. With emphasis on recovering copper and other precious metals, there have hitherto been no satisfactory methods to recover these toxic metals. In this paper, the criterion of separating metals from mixed metallic particles by vacuum metallurgy is built. The results show that the metals with high vapor pressure have been almost recovered completely, leading to a considerable reduction of environmental pollution. In addition, the purity of copper in mixed particles has been improved from about 80 wt % to over 98 wt %.

Modeling of wear behavior of Al/B{sub 4}C composites produced by powder metallurgy

Energy Technology Data Exchange (ETDEWEB)

Sahin, Ismail; Bektas, Asli [Gazi Univ., Ankara (Turkey). Dept. of Industrial Design Engineering; Guel, Ferhat; Cinci, Hanifi [Gazi Univ., Ankara (Turkey). Dept. of Materials and Metallurgy Engineering

2017-06-01

Wear characteristics of composites, Al matrix reinforced with B{sub 4}C particles percentages of 5, 10,15 and 20 produced by the powder metallurgy method were studied in this study. For this purpose, a mixture of Al and B{sub 4}C powders were pressed under 650 MPa pressure and then sintered at 635 C. The analysis of hardness, density and microstructure was performed. The produced samples were worn using a pin-on-disk abrasion device under 10, 20 and 30 N load through 500, 800 and 1200 mesh SiC abrasive papers. The obtained wear values were implemented in an artificial neural network (ANN) model having three inputs and one output using feed forward backpropagation Levenberg-Marquardt algorithm. Thus, the optimum wear conditions and hardness values were determined.

Microstructure and microanalysis studies of copper-nickel-tin alloys obtained by conventional powder metallurgy processing

International Nuclear Information System (INIS)

Monteiro, Waldemar A.; Carrio, Juan A.G.; Masson, T.J.; Vitor, E.; Abreu, C.D.; Marques, I.M.

2009-01-01

The aim of this paper was to analyze the microstructural development in samples of Cu-Ni-Sn alloys (weight %) obtained by powder metallurgy (P/M). The powders were mixed for 1/2 hour. After this, they were pressed, in a cold uniaxial pressing (1000 kPa). In the next step the specimens were sintered at temperatures varying from 650 up to 780 deg C under vacuum. Secondly, the samples were homogenized at 500 deg C for several special times. The alloys were characterized by optical microscopy, electrical conductivity and Vickers hardness. X-rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples. (author)

On the effect of TiC particles on the tensile properties and on the intrinsic two way effect of NiTi shape memory alloys produced by powder metallurgy

International Nuclear Information System (INIS)

Johansen, K.; Voggenreiter, H.; Eggeler, G.

1999-01-01

The present study investigates the tensile properties of a nickel titanium (NiTi) shape memory alloy (SMA) produced by powder metallurgy (PM) with and without TiC-particles. It discusses the effect of the addition of particles on the mechanical behavior in tension and studies the intrinsic two way effect (ε 2W ) after thermomechanical training. Special emphasis is placed on the stability of ε 2W after subsequent thermal cycling. The results are discussed on the basis of an analysis of the thermomechanical data and microstructural results. The present study shows that the PM route can produce NiTi SMAs with tensile properties which match those of materials produced by classical ingot metallurgy. Adding TiC particles to NiTi SMAs alters the phase transition temperatures (PTTs) and affects the SMA performance. Adding more than ten volume percent TiC particles results in early and brittle rupture during tensile loading. (orig.)

Cooling γ precipitation behavior and strengthening in powder metallurgy superalloy FGH4096

Institute of Scientific and Technical Information of China (English)

TIAN Gaofeng; JIA Chengchang; WEN Yin; LIU Guoquan; HU Benfu

2008-01-01

Two cooling schemes (continuous cooling and interrupted cooling tests) were applied to investigate the cooling γ precipitation behavior in powder metallurgy superalloy FGH4096.The effect of cooling rate on cooling γ precipitation and the development of γ precipitates during cooling process were involved in this study.The ultimate tensile strength (UTS) of the specimens in various cooling circumstances was tested.The experiential equations were obtained between the average sizes of secondary and tertiary γ precipitates,the strength,and cooling rate.The results show that they are inversely correlated with the cooling rate as well as the grain boundary changes from serrated to straight,the shape of secondary γ precipitates changes from irregular cuboidal to spherical,while the formed tertiary γ precipitates are always spherical.The interrupted cooling tests show that the average size of secondary γ precipitates increases as a linear function of interrupt temperature for a fixed cooling rate of 24℃/min.The strength first decreases and then increases against interrupt temperature,which is fundamentally caused by the multistage nucleation of γ precipitates during cooling process.

Residual Stresses in a NiCrY-Coated Powder Metallurgy Disk Superalloy

Science.gov (United States)

Gabb, Timothy P.; Rogers, Richard B.; Nesbitt, James A.; Puleo, Bernadette J.; Miller, Robert A.; Telesman, Ignacy; Draper, Susan L.; Locci, Ivan E.

2017-01-01

Protective ductile coatings will be necessary to mitigate oxidation and corrosion attack on superalloy disks exposed to increasing operating temperatures in some turbine engine environments. However, such coatings must be resistant to harmful surface cracking during service. The objective of this study was to investigate how residual stresses evolve in such coatings. Cylindrical gage fatigue specimens of powder metallurgy-processed disk superalloy LSHR were coated with a NiCrY coating, shot peened, and then subjected to fatigue in air at room and high temperatures. The effects of shot peening and fatigue cycling on average residual stresses and other aspects of the coating were assessed. Shot peening did induce beneficial compressive residual stresses in the coating and substrate. However, these stresses became more tensile in the coating with subsequent heating and contributed to cracking of the coating in long intervals of cycling at 760 C. Substantial compressive residual stresses remained in the substrate adjacent to the coating, sufficient to suppress fatigue cracking. The coating continued to protect the substrate from hot corrosion pitting, even after fatigue cracks initiated in the coating.

In Vitro Anthelmintic Activity of Crude Extracts of Aerial Parts of Cissus quadrangularis L. and Leaves of Schinus molle L. against Haemonchus contortus.

Science.gov (United States)

Zenebe, Selamawit; Feyera, Teka; Assefa, Solomon

2017-01-01

Haemonchus contortus, the causative agent of Haemonchosis, is the most economically important parasite in small ruminant production. Control with chemotherapy has not been successful due to rapid emergence of drug-resistant strains. There is a continuous search for alternative leads particularly from plants. The study aimed to evaluate the anthelmintic activity of crude methanolic extracts of leaves of Schinus molle and aerial parts of Cissus quadrangularis against H. contortus. Methods . Adult motility test and egg hatching inhibition assay were employed to investigate the in vitro adulticidal and egg hatching inhibitory effects of the extracts. Higher concentrations of the extracts (10 and 5 mg/ml) had a significantly superior adulticidal activity ( p molle and C. quadrangularis extracts indicated a maximum of 96% and 88% egg hatch inhibition, respectively, within the 48 hrs of exposure at 1 mg/ml. The current study evidenced that the crude methanolic extracts of the plants have promising adulticidal and egg hatching inhibitory effects against H. contortus .

From the TRIP effect and Quenching and Partitioning steels concepts to the development of new high-performance, lean powder metallurgy steels

International Nuclear Information System (INIS)

Torralba, José M.; Navarro, Alfonso; Campos, Mónica

2013-01-01

A new method of developing lean powder metallurgy steel is proposed. The microstructure of the steel is tailored by combining two different prealloyed steel grades. These materials open a new niche in steel grades for high-performance applications by using a low-cost method of production. Moreover, an alternative route to developing microstructures suitable for manufacturing TRIP and/or Q and P steels is proposed avoiding some of the complex steps that must otherwise be taken to obtain the proper starting microstructure

From the TRIP effect and Quenching and Partitioning steels concepts to the development of new high-performance, lean powder metallurgy steels

Energy Technology Data Exchange (ETDEWEB)

Torralba, José M., E-mail: josemanuel.torralba@imdea.org [IMDEA Materials Institute, C/Eric Kandel 2, 28906 - Getafe, Madrid (Spain); Department of Materials Science and Engineering, Universidad Carlos III Av. Universidad, 30, Leganés (Spain); Navarro, Alfonso; Campos, Mónica [Department of Materials Science and Engineering, Universidad Carlos III Av. Universidad, 30, Leganés (Spain)

2013-06-20

A new method of developing lean powder metallurgy steel is proposed. The microstructure of the steel is tailored by combining two different prealloyed steel grades. These materials open a new niche in steel grades for high-performance applications by using a low-cost method of production. Moreover, an alternative route to developing microstructures suitable for manufacturing TRIP and/or Q and P steels is proposed avoiding some of the complex steps that must otherwise be taken to obtain the proper starting microstructure.

Electron Beam Welding of Duplex Steels with using Heat Treatment

Science.gov (United States)

Schwarz, Ladislav; Vrtochová, Tatiana; Ulrich, Koloman

2010-01-01

This contribution presents characteristics, metallurgy and weldability of duplex steels with using concentrated energy source. The first part of the article describes metallurgy of duplex steels and the influence of nitrogen on their solidification. The second part focuses on weldability of duplex steels with using electron beam aimed on acceptable structure and corrosion resistance performed by multiple runs of defocused beam over the penetration weld.

Ninety years of mining and metallurgy in Trepča-sever conglomerate (part I

Directory of Open Access Journals (Sweden)

Nikolić Branislav

2017-01-01

Full Text Available Present company Trepča-Sever is formed by foreigners after the bombing of Serbia and Monten former Trepča Conglomerate located in northern part of Kosovo and Metohija, namely in three municipalities: North Kosovska Mitrovica, Zvečan and Leposavić. Main office of Trepča Conglomerate was always in Zvečan, flotation of lead-zinc ore (in the period of 1930- 1985, lead smelting and refining plants (founded in 1939, laboratory, Institute, electromechanical workshops and other ancillary services. In Leposavić flotation, ores of Kopaonik mines are processed, while financial and commercial services are located in the North Kosovska Mitrovica.

Solvent extraction studies on cadmium Part 3

International Nuclear Information System (INIS)

Alian, A.; El-Kot, A.

1976-01-01

An extraction study was performed on various concentrations of cadmium, zinc and cobalt halides in the presence of sulphuric acid. A long chain amine (Amberlite LA-2) and an organophosphorus solvent (TBP) were used. In most cases the value of the distribution ratio decreases with the increase of metal concentration in the aqueous phase. The various possibilities of chemical and radiochemical separations of cadmium from accompanying metal species are reported: separation of (sup109m)Ag from irradiated Cd targets, separation of (sup115m)In using HDEHP, separation of Cd and Zn from their mixtures. (T.G.)

Chemical composition, antioxidative and anti-inflammatory activity of extracts prepared from aerial parts of Oenothera biennis L. and Oenothera paradoxa Hudziok obtained after seeds cultivation.

Science.gov (United States)

Granica, Sebastian; Czerwińska, Monika E; Piwowarski, Jakub P; Ziaja, Maria; Kiss, Anna K

2013-01-30

In the present study we investigated the chemical composition of extracts prepared from aerial parts of Oenothera paradoxa Hudziok and Oenothera biennis L. and their antioxidative and anti-inflammatory activities. Ultra high pressure liquid chromatography (UHPLC)-DAD-MS/MS studies showed that both extracts contain a wide variety of polyphenols (39 identified constituents) among which macrocyclic ellagitannin turned out to be the main constituent. During the in vitro studies, using noncellular models, both extracts scavenged reactive oxygen species (ROS) in a concentration-dependent manner, and the lowest SC(50) values were obtained for O(2)(-) and H(2)O(2). Both extracts inhibited ROS production by stimulated human neutrophils. The stronger activity in the case of formyl-met-leu-phenylalanine stimulation suggests that both extracts may act through the receptor-dependent pathway. O. paradoxa extract and O. biennis extract exhibited anti-inflammatory activity by the inhibition of hyaluronidase and lipoxygenase in a concentration-dependent manner. The stronger activity of O.biennis extract toward lipoxygenase may be explained by its higher oenothein B content.

State space model extraction of thermohydraulic systems – Part II: A linear graph approach applied to a Brayton cycle-based power conversion unit

International Nuclear Information System (INIS)

Uren, Kenneth Richard; Schoor, George van

2013-01-01

This second paper in a two part series presents the application of a developed state space model extraction methodology applied to a Brayton cycle-based PCU (power conversion unit) of a PBMR (pebble bed modular reactor). The goal is to investigate if the state space extraction methodology can cope with larger and more complex thermohydraulic systems. In Part I the state space model extraction methodology for the purpose of control was described in detail and a state space representation was extracted for a U-tube system to illustrate the concept. In this paper a 25th order nonlinear state space representation in terms of the different energy domains is extracted. This state space representation is solved and the responses of a number of important states are compared with results obtained from a PBMR PCU Flownex ® model. Flownex ® is a validated thermo fluid simulation software package. The results show that the state space model closely resembles the dynamics of the PBMR PCU. This kind of model may be used for nonlinear MIMO (multi-input, multi-output) type of control strategies. However, there is still a need for linear state space models since many control system design and analysis techniques require a linear state space model. This issue is also addressed in this paper by showing how a linear state space model can be derived from the extracted nonlinear state space model. The linearised state space model is also validated by comparing the state space model to an existing linear Simulink ® model of the PBMR PCU system. - Highlights: • State space model extraction of a pebble bed modular reactor PCU (power conversion unit). • A 25th order nonlinear time varying state space model is obtained. • Linearisation of a nonlinear state space model for use in power output control. • Non-minimum phase characteristic that is challenging in terms of control. • Models derived are useful for MIMO control strategies

Anti-epileptogenic and antioxidant effect of Lavandula officinalis aerial part extract against pentylenetetrazol-induced kindling in male mice.

Science.gov (United States)

Rahmati, Batool; Khalili, Mohsen; Roghani, Mehrdad; Ahghari, Parisa

2013-06-21

Repeated application of Lavandula officinalis (L. officinalis) has been recommended for a long time in Iranian traditional medicine for some of nervous disorders like epilepsy and dementia. However, there is no available report for the effect of chronic administration of Lavandula extract in development (acquisition) of epilepsy. Therefore, this study was designed to investigate the anti-epileptogenic and antioxidant activity of repeated administration of Lavandula officinalis extract on pentylenetetrazol (PTZ) kindling seizures in mice model. Lavandula officinalis was tested for its ability (i) to suppress the seizure intensity and lethal effects of PTZ in kindled mice (anti-epileptogenic effect), (ii) to attenuate the PTZ-induced oxidative injury in the brain tissue (antioxidant effect) when given as a pretreatment prior to each PTZ injection during kindling development. Valproate (Val), a major antiepileptic drug, was also tested for comparison. Val and Lavandula officinalis extract showed anti-epileptogenic properties as they reduced seizure score of kindled mice and PTZ-induced mortality. In this regard, Lavandula officinalis was more effective than Val. Both Lavandula officinalis and Val suppressed brain nitric oxide (NO) level of kindled mice in comparison with the control and PTZ group. Meanwhile, Lavandula officinalis suppressed NO level more than Val and Lavandula officinalis also decreased brain MDA level relative to PTZ group. This is the first report to demonstrate NO suppressing and anti-epileptogenic effect of chronic administration of Lavandula officinalis extract on acquisition of epilepsy in PTZ kindling mice model. In this regard, Lavandula officinalis extract was more effective than Val, possibly and in part via brain NO suppression. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effects of carbon and hafnium concentrations in wrought powder-metallurgy superalloys based on nasa 2b-11 alloy

International Nuclear Information System (INIS)

Miner, R.V. Jr.

1976-01-01

A candidate alloy for advanced-temperature turbine engine disks and four modifications of that alloy with various C and Hf concentrations were produced as cross-rolled disks from prealloyed powder that was hot isostatically compacted. The mechanical properties, microstructures, and phase relations of the alloys are discussed in terms of their C and Hf concentrations. A low-C and high-Hf modification of IIB-11 had the best balance of mechanical properties for service below about 750 C. Because of their finer grain sizes, none of the powder-metallurgy alloys produced had the high-temperature rupture strength of conventionally cast and wrought IIB-11. (Author)

Powder metallurgy ferrous synchronizer ring with brass-based friction layer; Tetsu-do niso shoketsu synchronize ring no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Okajima, H; Yoshikawa, K; Miyajima, K; Sugiyama, M [Toyota Motor Corp., Aichi (Japan); Nakamura, M; Ito, M [Japan Powder Metallurgy Co. Ltd., Tokyo (Japan)

1997-10-01

Synchronizer rings for manual transmissions are generally made of brass or molybdenum coated brass. Powder metallurgy (PM) synchronizer ring was developed for the purpose of high performance and cost reduction. This synchronizer ring consists of the high strength PM ferrous ring that needs neither special densification nor heat treatment, and it has the brass-based friction layer. New joining technique was required because of that shape and two different materials. Powder of copper-phosphorus alloy are admixed with the friction material. While sintering, that melt and migrate to the interface. Then the friction layer and the ferrous ring are joined tightly. 7 refs., 9 figs., 6 tabs.

Presentations by AITEMIN for the 8th international congress on mining and metallurgy, Oviedo 1988. Ponencias de AITEMIN para el VIII congreso internacional de mineria y metalurgia, Oviedo 1988

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

Contains the work presented by AITEMIN staff at the 8th international congress on mining and metallurgy. A total of 19 papers are included from sessions with the following headings: general mining; coal mining; energy; applied geology; and safety. 12 of the papers have been abstracted separately.

Aproveitamento de silício proveniente de escória siderúrgica por cultivares de cana-de-açúcar Recovery of silicon from metallurgy slag by sugarcane cultivars

Directory of Open Access Journals (Sweden)

Robson Thiago Xavier de Sousa

2010-01-01

Full Text Available A cana-de-açúcar é uma espécie acumuladora de silício (Si, capaz de responder à adubação silicatada, principalmente, em solos pobres desse elemento. As escórias de siderurgia constituem em uma interessante fonte de Si para aplicação em solos cultivados com essa cultura. Objetivou-se estudar o aproveitamento do Si proveniente da escória siderúrgica pela cana-de-açúcar. O experimento foi desenvolvido em Uberlândia (MG, entre 15 de agosto de 2007 e 2 de maio de 2008. O delineamento experimental utilizado foi o de blocos ao acaso em esquema fatorial 2x4, sendo duas cultivares de cana-de-açúcar (SP81 - 3250 e RB86 - 7515 e quatro doses de Si (0, 100, 200 e 400 kg ha-1 em quatro repetições. A cana foi cultivada em tambores plásticos (200 L. A aplicação de escória de siderurgia (silicato aumentou o teor de Si disponível no solo e o teor foliar da cana-de-açúcar. A quantidade de Si acumulada pela parte aérea da cana proveniente do silicato aplicado variou entre 23% e 56%, respectivamente, para as variedades RB86-7515 e SP81-3250. Em média, 39% do Si absorvido pela parte aérea da cana foram provenientes do fertilizante aplicado (silicato.Sugarcane is a species that accumulates silicon (Si and is capable of responding to Si applications, especially in soils lacking Si.. Metallurgy slag is an interesting source of Si for soils cultivated with this crop. The aim of this study was to evaluate the recovery of Si from metallurgy slag by sugarcane. The experiment was carried out at Uberlândia-MG, from August 15, 2007 to May 02, 2008. The experimental design was randomized in a 2 x 4 factorial arrangement being two cultivate of sugarcane (SP81 - 3250 and RB86 - 7515 and four Silicon doses (0, 100, 200 and 400 kg ha-1 with four replications. The sugarcane was cultivated in plastic drums (200 L. The application of slag (silicates increased the content of available silicon in soil and leaf of sugarcane. The amount of Si accumulated in

Hepatoprotective activity of aerial part and root extracts of ...

African Journals Online (AJOL)

) extracts of Schwenckia americana Linn (Solanaceae) against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats was studied. Adult Swiss albino rats of either sex were divided into six groups (n=6). Groups I-IV received MME and RME ...

Effects of TiN nanoparticles on the microstructure and properties of W–30Cu composites prepared via electroless plating and powder metallurgy

International Nuclear Information System (INIS)

Huang, Li-Mei; Luo, Lai-Ma; Zhao, Mei-Ling; Luo, Guang-Nan; Zhu, Xiao-Yong; Cheng, Ji-Gui; Zan, Xiang; Wu, Yu-Cheng

2015-01-01

Highlights: • TiN-doped W–Cu composite was successfully prepared by electroless plating and powder metallurgy. • TiN-doped W–Cu significantly affected the microstructure and properties of the composites. • W–Cu composite with 0.25 wt.% TiN possesses the best comprehensive performance. - Abstract: W–30Cu/(0, 0.25, 0.5, 1, and 2) wt.% TiN composites were prepared via electroless plating with simplified pretreatment and powder metallurgy. The phase and morphology of W–Cu/TiN composite powders and sintered W–Cu/TiN samples were characterized via X-ray diffraction and field emission scanning electron microscopy. Transmission electron microscopy was performed to characterize the microstructure of the sintered W–Cu/TiN samples. The relative density, hardness, electrical conductivity, and compressive strength of the sintered samples were examined. Results showed that W–30Cu composite powders with a uniform structure can be obtained using W powder pretreated with nitric acid, ammonium fluoride, and hydrofluoric acid followed by electroless Cu plating. The addition of TiN nanoparticles significantly affected the microstructure and properties of the W–30Cu composites. A good combination of the compressive strength and hardness of the W–30Cu composite material can be obtained by incorporating the TiN additive at 0.25 wt.%. However, the relative density and electrical conductivity slightly decreased

POSSIBLE USES OF PLASMA IN POWDER METALLURGY, WITH PARTICULAR REFERENCE TO SPHEROIDIZATION. Mozliwosci wykorzystania plazmy w zaganieniach metalurgii proszkow, ze szczegolnym uwzglednieniem procesu sferoidyzacji

Energy Technology Data Exchange (ETDEWEB)

Rutkowski, Wladyslaw; Szteke, Witold

1971-09-15

The present work contains a discussion of the problems of applying plasma in powder-metallurgical processes, application of powders to other processes with the use of plasma, and the application of other products of powder metallurgy in the plasma process. Results obtained with the spheroidization of AL{sub 2}O{sub 3}, Ta, and Ni powders are presented, as are the results of metallographic and microscopic investigations on these powders.

Effect of Extract of Aerial Parts of Urtica dioica (Urticaceae) on the ...

African Journals Online (AJOL)

Methods: Three different U. dioica extracts, viz, chloroform, methanol (80 %) and water extracts, were ... (DPPH) radical scavenging and soybean oil models. ... Conclusion: These findings demonstrate that mixing soybean oil with U. dioica ...

Microstructure, mechanical behavior and biocompatibility of powder metallurgy Nb-Ti-Ta alloys as biomedical material.

Science.gov (United States)

Liu, Jue; Chang, Lin; Liu, Hairong; Li, Yongsheng; Yang, Hailin; Ruan, Jianming

2017-02-01

Microstructures, mechanical properties, apatite-forming ability and in vitro experiments were studied for Nb-25Ti-xTa (x=10, 15, 20, 25, 35at.%) alloys fabricated by powder metallurgy. It is confirmed that the alloys could achieve a relative density over 80%. Meanwhile, the increase in Ta content enhances the tensile strength, elastic modulus and hardness of the as-sintered alloys. When increasing the sintering temperatures, the microstructure became more homogeneous for β phase, resulting in a decrease in the modulus and strength. Moreover, the alloys showed a good biocompatibility due to the absence of cytotoxic elements, and were suitable for apatite formation and cell adhesion. In conclusion, Nb-25Ti-xTa alloys are potentially useful in biomedical applications with their mechanical and biological properties being evaluated in this work. Copyright © 2016 Elsevier B.V. All rights reserved.

In vitro antifungal activities of extracts of fruits and other morphological parts of xanthium strumarium against the plant pathogen, rhizoctonia solani

Energy Technology Data Exchange (ETDEWEB)

Osman, N. U. [University of Tabuk (Saudi Arabia); Alsiddeeg, S. E. [University of Gezira, Wad Medani (Sudan). Dept. of Oilseed Processing Research

2014-03-15

In vitro antifungal activity of different plant parts of Xanthium strumarium (Compositae) was investigated against Rhizoctonia solani to seek safe natural alternatives to the harmful synthetic fungicides. The most active plant parts of X. strumarium were seeds, extracted with n-hexane and the leaves, extracted with absolute ethanol. The two treatments resulted in growth inhibition diameters of 45 mm and 47 mm, respectively. The value of MIC lied between 350.0 and 175.0 mg of Xanthium oil/mL. Gas liquid chromatography of the seed oil of X. strumarium revealed the presence of the usual fatty acids, palmitoleic (7.6%), oleic (21.6%) and linoleic (70.4%). The oil was separated into free fatty acids fraction and unsaponifiable matter fraction. The unsaponifiable matter fraction was separated on TLC, out of six separated compounds, two were active against R. solani. The infrared spectra (FTIR) of these two purified compounds pointed to a long chain hydrocarbon back-bone for both, one of them possessing in addition, an alcoholic moiety. (author)

In vitro antifungal activities of extracts of fruits and other morphological parts of xanthium strumarium against the plant pathogen, rhizoctonia solani

International Nuclear Information System (INIS)

Osman, N.U.; Alsiddeeg, S.E.

2014-01-01

In vitro antifungal activity of different plant parts of Xanthium strumarium (Compositae) was investigated against Rhizoctonia solani to seek safe natural alternatives to the harmful synthetic fungicides. The most active plant parts of X. strumarium were seeds, extracted with n-hexane and the leaves, extracted with absolute ethanol. The two treatments resulted in growth inhibition diameters of 45 mm and 47 mm, respectively. The value of MIC lied between 350.0 and 175.0 mg of Xanthium oil/mL. Gas liquid chromatography of the seed oil of X. strumarium revealed the presence of the usual fatty acids, palmitoleic (7.6%), oleic (21.6%) and linoleic (70.4%). The oil was separated into free fatty acids fraction and unsaponifiable matter fraction. The unsaponifiable matter fraction was separated on TLC, out of six separated compounds, two were active against R. solani. The infrared spectra (FTIR) of these two purified compounds pointed to a long chain hydrocarbon back-bone for both, one of them possessing in addition, an alcoholic moiety. (author)

Quality Parameters of Curcuma Longa L. Extracts by Supercritical Fluid Extraction (SFE) and Ultrasonic Assisted Extraction (UAE)

International Nuclear Information System (INIS)

Zaibunnisa Abdul Haiyee; Siti Hafsah Mohd Shah; Khudzir Ismail; Nooraain Hashim; Wan Iryani Wan Ismail

2016-01-01

Turmeric is one of the prominently use herbal plants due to its diverse beneficial effects especially in Indian medicine. The rhizome part of the turmeric contains valuable compounds which have been said to owe its antimicrobial effects, anti-cancer, anti-inflammatory and enhance wound healing. Due to its short-life span and perishable properties, the conversion of the rhizome into turmeric extract is desirable. Several methods have been used for extraction such as Soxhlet extraction and pressurized liquid extraction (PLE). However, these techniques are tedious, laborious, time consuming and involves the usage of toxic organic solvent, of which safeness of the end product is doubtful. In this study, a rapid, reliable and green extraction method of supercritical fluid extraction (SFE) and ultrasonic assisted extraction (UAE) were used. SFE without modifier has resulted in 0.0006 mg/ 100 g of curcuminoids concentration and 5.62 % of yield (dry weight basis). UAE using ethanol was able to produce significantly the highest yield (6.40 %, dry weight basis) and the highest curcuminoids concentration (0.1020 mg/ 100 g). However, SFE was able to produce extract that contain significantly higher major volatile compounds; tumerone, ar-turmerone and curlone. Therefore, this study proves that both extraction methods were able to produce high quality turmeric extract. (author)

Metallurgy of platinoids. Studies of industrial cases; Metallurgie des platinoides. Etudes de cas industriels

Energy Technology Data Exchange (ETDEWEB)

Blazy, P. [Ecole Nationale Superieure de Geologie, 54 - Vandoeuvre les Nancy (France); Jdid, E. A. [Institut National Polytechnique de Lorraine (ENSG/INPL/CNRS UMR 7569), 54 Vandoeuvre les Nancy (France)

2004-03-01

The platinoids deposits, currently in exploitation, are often associated with dunitic and gabbroitic ultra-basic rocks containing copper, nickel and iron sulfides. The proportion of platinoids in these deposits is variable and requires generally an adaptation of the industrial processes for their recovery. Nevertheless, we can consider that the classical industrial way consists to treat the composite concentrates of copper-nickel-platinoids sulfides by melting/conversion operations following by hydrometallurgical operations of recovery of the basic metals Cu, Ni. These last ones concentrate the platinoids in leaching residues. In these residues, the platinoids are extracted and separated by hydrometallurgical ways including different techniques: dissolution, selective precipitation, distillation, solvent extraction, resins...The great variety of uses of platinoids makes their recycling difficult. The wastes are often too complex for being economically recycling. The environmental protection depends of the type of industry (metallurgical, chemical, mining). Some products present risks of fire and explosion. The toxicity often appears by superficial allergies and by serious troubles in case of ingestion of soluble salts. (O.M.)

Solvent extraction

Energy Technology Data Exchange (ETDEWEB)

Coombs, D.M.; Latimer, E.G.

1988-01-05

It is an object of this invention to provide for the demetallization and general upgrading of heavy oil via a solvent extracton process, and to improve the efficiency of solvent extraction operations. The yield and demetallization of product oil form heavy high-metal content oil is maximized by solvent extractions which employ either or all of the following techniques: premixing of a minor amount of the solvent with feed and using countercurrent flow for the remaining solvent; use of certain solvent/free ratios; use of segmental baffle tray extraction column internals and the proper extraction column residence time. The solvent premix/countercurrent flow feature of the invention substantially improves extractions where temperatures and pressures above the critical point of the solvent are used. By using this technique, a greater yield of extract oil can be obtained at the same metals content or a lower metals-containing extract oil product can be obtained at the same yield. Furthermore, the premixing of part of the solvent with the feed before countercurrent extraction gives high extract oil yields and high quality demetallization. The solvent/feed ratio features of the invention substanially lower the captial and operating costs for such processes while not suffering a loss in selectivity for metals rejection. The column internals and rsidence time features of the invention further improve the extractor metals rejection at a constant yield or allow for an increase in extract oil yield at a constant extract oil metals content. 13 figs., 3 tabs.

Metal ion extractant in microemulsions: where solvent extraction and surfactant science meet

International Nuclear Information System (INIS)

Bauer, C.

2011-01-01

The presented work describes the supramolecular structure of mixtures of a hydrophilic surfactant n-octyl-beta-glucoside (C8G1), and the hydrophobic metal ion extractant tributylphosphate (TBP) in n-dodecane/water as well as in the presence of salts. In the first part, basic solvent extraction system, composed of water, oil and extractant, will be introduced. The focus, however, lies on the extraction of multivalent metal ions from the aqueous phase. During this extraction process and in the following thermodynamic equilibrium, aggregation and phase transition in supramolecular assemblies occur, which are already described in literature. Notably, these reports rest on individual studies and specific conclusions, while a general concept is still missing. We therefore suggest the use of generalized phase diagrams to present the physico-chemical behaviour of (amphiphilic) extractant systems. These phase diagrams facilitated the development of a thermodynamic model based on molecular geometry and packing of the extractant molecules in the oil phase. As a result, we are now in the position to predict size and water content of extractant aggregates and, thus, verify the experimental results by calculation.Consequently, the second part presents a systematic study of the aqueous and organic phase of water/C8G1 and water/oil/TBP mixtures. The focus lies on understanding the interaction between metal ions and both amphiphilic molecules by means of small angle x-ray scattering (SAXS), dynamic light scattering (DLS) and UV-Vis spectroscopy. We confirmed the assumption that extraction of metal ions is driven by TBP, while C8G1 remains passive. In the third and last part, microemulsions of C8G1, TBP, water (and salt) and n-dodecane are characterized by small angle neutron scattering (SANS), and chemical analytics (Karl Fischer, total organic carbon, ICP-OES,...). The co-surfactant behaviour of TBP was highlighted by comparison to the classical n-alcohol (4≤n≤8) co

Powder metallurgy development at SRL

International Nuclear Information System (INIS)

Peacock, H.B.

1993-01-01

The Savannah River Laboratory (SRL) is developing a powder metallurgy (P/M) process for manufacturing reactor-grade fuel tubes containing high wt % U 3 O 8 -Al cores clad with 8001 aluminum. The P/M cores are made by isostatic compaction. They are assembled in billets, outgassed, and hot-extruded using conventional coextrusion techniques. Cores have been compacted with up to 100% U3O 8 and tubes extruded with 80 wt % oxide cores. Irradiation tests have been made using P/M core tubes in the Savannah River reactors. These tubes contained U 3 O 8 concentrations up to 59 wt % and no significant swelling or blistering occurred. The tubes were irradiated to ∼ 40% burnup or 1.6x10 21 fissions/cc of core. This report discusses both small-scale and production tests for high-density P/M fuel development. The purpose of the P/M development program at SRL is to: determine the maximum U 3 O 8 content that can be fabricated into thin wall tubes, irradiate high-density tubes to high burnup and assess irradiation and dimensional stability, continue metal forming studies for extrusion and drawing, and evaluate hydrostatic extrusion and hydrostatically assisted drawing of P/M core tubes. Experimental results of testing the fuel assemblies performance so far indicate that: cores containing fine (-325 mesh) U 3 O 8 and aluminum powders can be made practically free of high-density areas using the outlined P/M pre blending and sieving techniques. U 3 O 8 -Al cores can be isostatically compacted with up to 100 wt U 3 O 8 and tubes successfully extruded with up to 80 wt oxide; fission gas blistering of U 3 O 8 -Al P/M tubes as indicated by the blister tests is a function of fissions/cc of U 3 O 8 in the core; Decreasing the fission density of oxide increases the threshold temperature for blister formation; U 3 O 8 -Al P/M fuel tubes with up to 59 wt U 3 O 8 have been successfully irradiated in SRP reactor to 1.6 x 10 21 fissions/cc of core or 7 x 10 20 fissions/cc of U 3 O 8 small

Fabrication and characterization of Am, Np and Cm bearing MOX fuel obtained by conventional powder metallurgy

Energy Technology Data Exchange (ETDEWEB)

Jankowiak, A.; Leorier, C.; Desmouliere, F.; Donnet, L. [Commissariat a l' Energie Atomique (CEA), CEA/DEN/VRH/DTEC/SDTC/LEMA, 30207 Bagnols-sur-Ceze cedex (France)

2008-07-01

Transmutation of minor actinides enables to produce energy and to turn them into shorter-lived nuclides. This promising way to reduce the long-term waste radiotoxicity is world wide investigated. In the framework of the Global Actinide Cycle International Demonstration and regarding the homogeneous recycling for transmutation in fast reactors, minor actinides (Am, Np, Cm) bearing MOX fuel pellets were fabricated in the ATALANTE facility by a conventional powder metallurgy process (milling then pressing and finally sintering). The sintered pellets were submitted to a visual inspection where neither crack nor strain was detected. In addition, the pellets exhibit a density in the range 93-96% TD which makes them proper to the irradiation in fast reactors. The pellets were characterized by XRD (X radiation diffraction) and SEM (scanning electron microscopy) combined to image analysis. (authors)

Mechanical strength and thermophysical properties of PM212: A high temperature self-lubricating powder metallurgy composite

Science.gov (United States)

Edwards, Phillip M.; Sliney, Harold E.; Dellacorte, Christopher; Whittenberger, J. Daniel; Martineau, Robert R.

1990-01-01

A powder metallurgy composite, PM212, composed of metal bonded chromium carbide and solid lubricants is shown to be self-lubricating to a maximum application temperature of 900 C. The high temperature compressive strength, tensile strength, thermal expansion and thermal conductivity data needed to design PM212 sliding contact bearings and seals are reported for sintered and isostatically pressed (HIPed) versions of PM212. Other properties presented are room temperature density, hardness, and elastic modulus. In general, both versions appear to have adequate strength to be considered as sliding contact bearing materials, but the HIPed version, which is fully dense, is much stronger than the sintered version which contains about 20 percent pore volume. The sintered material is less costly to make, but the HIPed version is better where high compressive strength is important.

Application of powder metallurgy techniques to produce improved bearing elements for liquid rocket engines

Science.gov (United States)

Moracz, D. J.; Shipley, R. J.; Moxson, V. S.; Killman, R. J.; Munson, H. E.

1992-01-01

The objective was to apply powder metallurgy techniques for the production of improved bearing elements, specifically balls and races, for advanced cryogenic turbopump bearings. The materials and fabrication techniques evaluated were judged on the basis of their ability to improve fatigue life, wear resistance, and corrosion resistance of Space Shuttle Main Engine (SSME) propellant bearings over the currently used 440C. An extensive list of candidate bearing alloys in five different categories was considered: tool/die steels, through hardened stainless steels, cobalt-base alloys, and gear steels. Testing of alloys for final consideration included hardness, rolling contact fatigue, cross cylinder wear, elevated temperature wear, room and cryogenic fracture toughness, stress corrosion cracking, and five-ball (rolling-sliding element) testing. Results of the program indicated two alloys that showed promise for improved bearing elements. These alloys were MRC-2001 and X-405. 57mm bearings were fabricated from the MRC-2001 alloy for further actual hardware rig testing by NASA-MSFC.

Simulation Investigation on Application of Powder Metallurgy Damping Effect in Water Hydraulic Pump

Directory of Open Access Journals (Sweden)

Shi Weijie

2018-01-01

Full Text Available Over the years, the hydrostatic balance slipper is often used to make the hydraulic lubrication film formed between the swash plate and the slipper. In this paper, a slipper containing the powder metallurgy (PM composite material is proposed. The porous characteristics have an automatic damping effect, which can improve the tribological characteristics of the slipper. Based on the Reynolds equation, porous Darcy law and continuity equation, a lubrication model of PM damper is proposed to analyze the damping effect of PM in this paper. The proposed model is calculated using the finite volume method to capture the water film characteristics. Effects of length, diameter and porosity of the PM damper on the water film thickness are investigated. The results show that the water film can be formed by adopting the PM damper. In order to ensure the slipper with PM damper to form hydrostatic support, the length, diameter and porosity of PM damper is recommended to be 5 mm, 8 mm and 0.7, respectively.

Air Emissions of Selected Substances from Particular Sectors Including Metallurgy in Poland

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Kargulewicz I.

2017-03-01

Full Text Available This article presents data on the anthropogenic air emissions of selected substances (CO2, SO2, total suspended particles (TSP, dioxins and furans (PCDD/F, Pb and Cd subject to reporting under the Climate Convention (UNFCCC or the Convention on Long-range Transboundary Air Pollution (UNECE CLRTAP. It also presents the national emissions of these substances in 2014 by the major source categories and defines the share of metal production in these emissions. Analysis is based on national emission inventory reports. Most important source of air emission in case of CO2 and SO2 is 1.A.1 Energy industries category. TSP and PCDD/F are emitted mainly from fuel combustion in small sources (i.a. households. Emission of heavy metals (Pb and Cd is connected mostly with 1.A.2. Manufacturing industries and construction category. Metallurgy is significant source of emission only for lead and cadmium from among all considered substances. The shares of particular sectors in the national emissions of given pollutants are important, in view of the possible reduction measures and the determination in which industries they could bring about tangible results.

Microstructural investigation of aluminum-graphene nano platelets composites prepared by powder metallurgy

Science.gov (United States)

Sreearravind, M.; Peddavarapu, Sreehari; Raghuraman, S.

2018-04-01

Recently, Graphene has attracted a large variety of scientific communities due to its inimitable properties. Typically, Graphene Nanoplatelets (GNPs) are ideal reinforcements for the production of nanocomposites due to its excellent mechanical properties for strength enhancement. This paper reports the Aluminum-Graphene Nanoplatelets (Al/GNPs) composites synthesized through powder metallurgy method. The microstructural investigation was carried out to study the GNPs integration on the Al matrix. For this study, the samples Al-2wt% GNPs, Al-3wt% GNPs and Al- 4wt% GNPs are high-energy ball milled at 200rpm and sintered at 500°C,550°C, and 600°C. Microstructural characterization is carried out with optical microscopy, Scanning electron microscopy. Rockwell hardness test is conducted to evaluate the hardness behavior in Al/GNPs. Microstructural analysis revealed the homogeneous dispersion of GNPs in the Al matrix in all the samples. It is observed that the existence of the graphene nanoparticles and the rise of their concentrations in the aluminum matrix (2 wt.% to 4 wt.%) as reinforcement in addition to rising the sintering temperature (450°C to 600°C) greatly improve the mechanical properties of Al/GNPs composites.

Progress report on nuclear science and technology in China (Vol.3). Proceedings of academic annual meeting of China Nuclear Society in 2013, No.2--uranium mining and metallurgy sub-volume

International Nuclear Information System (INIS)

2014-05-01

Progress report on nuclear science and technology in China (Vol. 3) includes 48 articles which are communicated on the third national academic annual meeting of China Nuclear Society. There are 10 books totally. This is the second one, the content is about uranium mining and metallurgy sub-volume

Progress report on nuclear science and technology in China (Vol.1). Proceedings of academic annual meeting of China Nuclear Society in 2009, No.2--uranium mining and metallurgy sub-volume

International Nuclear Information System (INIS)

2010-11-01

Progress report on nuclear science and technology in China (Vol. 1) includes 889 articles which are communicated on the first national academic annual meeting of China Nuclear Society. There are 10 books totally. This is the second one, the content is about uranium mining, uranium metallurgy and nuclear power.

Superplasticity in powder metallurgy aluminum alloys and composites

International Nuclear Information System (INIS)

Mishra, R.S.; Bieler, T.R.; Mukherjee, A.K.

1995-01-01

Superplasticity in powder metallurgy Al alloys and composites has been reviewed through a detailed analysis. The stress-strain curves can be put into 4 categories: classical well-behaved type, continuous strain hardening type, continuous strain softening type and complex type. The origin of these different types of is discussed. The microstructural features of the processed material and the role of strain have been reviewed. The role of increasing misorientation of low angle boundaries to high angle boundaries by lattice dislocation absorption is examined. Threshold stresses have been determined and analyzed. The parametric dependencies for superplastic flow in modified conventional aluminum alloys, mechanically alloyed alloys and Al alloy matrix composites is determined to elucidate the superplastic mechanism at high strain rates. The role of incipient melting has been analyzed. A stress exponent of 2, an activation energy equal to that for grain boundary diffusion and a grain size dependence of 2 generally describes superplastic flow in modified conventional Al alloys and mechanically alloyed alloys. The present results agree well with the predictions of grain boundary sliding models. This suggests that the mechanism of high strain rate superplasticity in the above-mentioned alloys is similar to conventional superplasticity. The shift of optimum superplastic strain rates to higher values is a consequence of microstructural refinement. The parametric dependencies for superplasticity in aluminum alloy matrix composites, however, is different. A true activation energy of superplasticity in aluminum alloy matrix composites, however, is different. A true activation energy of 313 kJ/mol best describes the composites having SiC reinforcements. The role of shape of the reinforcement (particle or whisker) and processing history is addressed. The analysis suggests that the mechanism for superplasticity in composites is interface diffusion controlled grain boundary sliding

Applications of Phase Diagrams in Metallurgy and Ceramics: Proceedings of a Workshop Held at the National Bureau of Standards, Gaithersburg, Maryland, January 10-12, 1977. Volumes 1 [and] 2.

Science.gov (United States)

Carter, G. C., Ed.

This document is a special National Bureau of Standards publication on a Workshop on Applications of Phase Diagrams in Metallurgy and Ceramics. The purposes of the Workshop were: (1) to assess the current national and international status of phase diagram determinations and evaluations for alloys, ceramics and semiconductors; (2) to determine the…

Effect of Aerial Parts Extract of Echinophora Platyloba.L on Liver and Kidney Function Tests in Obese Hypercholesterolaemia Rats

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H Aqababa

2016-01-01

Full Text Available Introduction: Obesity and its complications such as hypertension, fatty liver, type 2 diabetes and kidney failure, can be mentioned as the main life-threating elements. Therefore, this study aimed to evaluate the effect of air parts extract of Echinophora platyloba.L (EP on changes in body weight as well as liver and kidney function tests in hypercholesterolaemia obese rats. Methods: In this experimental study, 40 male Wistar rats were divided in to five groups (n =8 including a control group with normal control diet, control hyperlipidemia group with fatty food diet and hypertriglyceridemia treatment groups which recieved the minimum dose (100 mg/kg, average dose (200 mg/kg maximum dose (300 mg/kg of EP extract via a gavage. At the end of this period (42 days, to measure cholesterol, creatinine, blood urea nitrogen, bilirubin, albumin, total protein, alanine Aminotransferase (ALT and aspartate Aminotransferase (AST and alkaline phosphatase (ALP, the blood samples were collected and the study data were analyzed. Results: Cholesterol, ALT, AST and ALP were reported to significantly decrease (in the minimum and maximum dose groups compared to the control group (P≤0.05. Albumin and total protein in the maximum dose extract group significantly increased compared to the control group (P≤0.05. Moreover, body weight in the group receiving the minimum dose of extract showed a significant decrease compared to the control group (P≤0.05. Conclusion: EP extract, specifically in the minimal doses, in addition to protecting liver, could be recommended as a good candidate in regard with the treatment of blood lipids, and body extra weight.

Effects of Plasma ZrN Metallurgy and Shot Peening Duplex Treatment on Fretting Wear and Fretting Fatigue Behavior of Ti6Al4V Alloy.

Science.gov (United States)

Tang, Jingang; Liu, Daoxin; Zhang, Xiaohua; Du, Dongxing; Yu, Shouming

2016-03-23

A metallurgical zirconium nitride (ZrN) layer was fabricated using glow metallurgy using nitriding with zirconiuming prior treatment of the Ti6Al4V alloy. The microstructure, composition and microhardness of the corresponding layer were studied. The influence of this treatment on fretting wear (FW) and fretting fatigue (FF) behavior of the Ti6Al4V alloy was studied. The composite layer consisted of an 8-μm-thick ZrN compound layer and a 50-μm-thick nitrogen-rich Zr-Ti solid solution layer. The surface microhardness of the composite layer is 1775 HK 0.1 . A gradient in cross-sectional microhardness distribution exists in the layer. The plasma ZrN metallurgical layer improves the FW resistance of the Ti6Al4V alloy, but reduces the base FF resistance. This occurs because the improvement in surface hardness results in lowering of the toughness and increasing in the notch sensitivity. Compared with shot peening treatment, plasma ZrN metallurgy and shot peening composite treatment improves the FW resistance and enhances the FF resistance of the Ti6Al4V alloy. This is attributed to the introduction of a compressive stress field. The combination of toughness, strength, FW resistance and fatigue resistance enhance the FF resistance for titanium alloy.

In Vitro Anthelmintic Activity of Crude Extracts of Aerial Parts of Cissus quadrangularis L. and Leaves of Schinus molle L. against Haemonchus contortus

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Selamawit Zenebe

2017-01-01

Full Text Available Background. Haemonchus contortus, the causative agent of Haemonchosis, is the most economically important parasite in small ruminant production. Control with chemotherapy has not been successful due to rapid emergence of drug-resistant strains. There is a continuous search for alternative leads particularly from plants. The study aimed to evaluate the anthelmintic activity of crude methanolic extracts of leaves of Schinus molle and aerial parts of Cissus quadrangularis against H. contortus. Methods. Adult motility test and egg hatching inhibition assay were employed to investigate the in vitro adulticidal and egg hatching inhibitory effects of the extracts. Results. Higher concentrations of the extracts (10 and 5 mg/ml had a significantly superior adulticidal activity (p<0.05 compared to the negative control and lower concentration levels, which was comparable to albendazole. Similarly, the relative egg hatch inhibition efficacy of S. molle and C. quadrangularis extracts indicated a maximum of 96% and 88% egg hatch inhibition, respectively, within the 48 hrs of exposure at 1 mg/ml. Conclusion. The current study evidenced that the crude methanolic extracts of the plants have promising adulticidal and egg hatching inhibitory effects against H. contortus.

Automatic Contour Extraction from 2D Image

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Panagiotis GIOANNIS

2011-03-01

Full Text Available Aim: To develop a method for automatic contour extraction from a 2D image. Material and Method: The method is divided in two basic parts where the user initially chooses the starting point and the threshold. Finally the method is applied to computed tomography of bone images. Results: An interesting method is developed which can lead to a successful boundary extraction of 2D images. Specifically data extracted from a computed tomography images can be used for 2D bone reconstruction. Conclusions: We believe that such an algorithm or part of it can be applied on several other applications for shape feature extraction in medical image analysis and generally at computer graphics.

Advanced Mechanical Properties of a Powder Metallurgy Ti-Al-N Alloy Doped with Ultrahigh Nitrogen Concentration

Science.gov (United States)

Shen, J.; Chen, B.; Umeda, J.; Kondoh, K.

2018-03-01

Titanium and its alloys are recognized for their attractive properties. However, high-performance Ti alloys are often alloyed with rare or noble-metal elements. In the present study, Ti alloys doped with only ubiquitous elements were produced via powder metallurgy. The experimental results showed that pure Ti with 1.5 wt.% AlN incorporated exhibited excellent tensile properties, superior to similarly extruded Ti-6Al-4V. Further analysis revealed that its remarkably advanced strength could primarily be attributed to nitrogen solid-solution strengthening, accounting for nearly 80% of the strength increase of the material. In addition, despite the ultrahigh nitrogen concentration up to 0.809 wt.%, the Ti-1.5AlN sample showed elongation to failure of 10%. This result exceeds the well-known limitation for nitrogen (over 0.45 wt.%) that causes embrittlement of Ti alloys.