Wyniki wyszukiwania - Biblioteka Nauki

1

Quality of bimetal Al-Cu joint after explosive cladding

100%

Berski S. , Stradomski Z. , Dyja H.

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2007

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tom Vol. 22, nr 1

73-76

EN

Purpose: An analysis of quality of bimetallic joint between aluminium and copper layers of billet for extrusion process is the subject of the work. Design/methodology/approach: For preparing the quality analysis of particular layer of bimetal, the shearing test were done. During the tests the maximal stress for particular sets of the bimetal was established. For chosen cases the metallographic research of Al-Cu joint were done. Findings: The geometry of the cylindrical set and explosive cladding process parameters which allow to obtain the cylindrical bimetallic billets without cracks and delaminations and also with uniform cladded layer along and across the billet. Research limitations/implications: The analysis is concerning the explosive joint of pure aluminium A1995 and electrolytic copper M1E 99,97 in cylindrical sets. In the future research the analysis of this kind of joints after direct extrusion process is planning. Practical implications: The analysis could be helpful for more effective designing of the bimetal billets trough the explosive cladding process and next for the plastic working processes. Originality/value: During the extrusion process with high value of extrusion ratio the delamination of the billet layers especially on the boundary of the layers is observed, this fact causes that joint after the metal working processes has lower strength even than components of the bimetal billet. So very important task is establishing the geometry set and explosive parameters to obtain the best quality of the joint.

2

Analysis of airborne metal containing particles with EDX/EDS detectors in electron microscopes

99%

Sielicki P. , Janik H. , Guzman A. , Reynolds A. , Namieśnik J.

Open Chemistry

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2011

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tom 9

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nr 2

308-313

EN

In years 2006–2010 particulate matter analysis was undertaken for dust samples collected from Gdansk and London area in order to compare their morphology and composition. Part of those studies was devoted to analysis of particulate matter (PM) bearing metals. Characterization of the morphology and size of the particles collected onto the filters was performed using a scanning electron microscope (SEM) and transmission electron microscope (TEM). Both electron microscopes were equipped with energy dispersive X-ray spectrometers to identify the elemental composition of the particles. On analysis of the X-ray spectra acquired by both TEM and SEM, the particles were divided into 10 groups as follows: Al-rich, Ba-rich, C-rich, Ca-rich, Cl-rich, Fe-rich, Mg-rich, Na-rich, S-rich, Si-rich. Speciation of the particles based on the major element and accompanying minor elements yielded 34 particle types. However, some pairs of elements repeat, for instance: Na-Cl and Cl-Na, Al-S and S-Al, Si-Al and Al-Si, S-Ca and Ca-S. These are undoubtedly the same types of particles; variation in peak heights of the major and minor elements is normal in a mixed particle population.

3

Silver selenide modification of polyamide fabric

99%

Milašienė D. , Ivanauskas R.

Open Chemistry

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2013

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tom 11

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nr 12

1976-1980

EN

Formation of a silver selenide layer on silicone coated polyamide cloth was investigated. Fabric samples were selenized in potassium selenotrithionate (K2SeS2O6) solution then treated with AgNO3 solution. Formation of a silver selenide particle layer on the surface was confirmed by a change in appearance, X-ray diffraction, and EDX analysis. XRD revealed two phases: orthorhombic naumannite (Ag2Se) and monoclinic selenium (Se8). SEM showed that the fabric macrostructure and the multifilament yarn microstructure was preserved. The silver selenide particles ranged from 100 nm to more than 20 µm. [...]

4

Effects of Acid Treatment on the SEM-EDX Characteristics of Kaolin Clay

99%

Yahaya S. , Jikan S. S. , Badarulzaman N. A. , Adamu A. D.

Path of Science

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2017

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tom 3

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nr 9

4001-4005

EN

Raw kaolin was refluxed by sulphuric acid in variable concentrations of 2 M, 4 M, 6 M and 8 M. The morphology and elemental compositions of the acid-leached kaolin were analyse by Field Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray analysis (EDX) respectively. The disintegration and leaching of Al3+ ions of the clay are determined by FESEM studies. The acid treatment increases the silicon content and decreases aluminium content as revealed by EDX analysis. The leaching of Al3+ ions increases with gradual increase in concentration of the acid. Therefore, kaolin reflux with acid at lower strength (2 M and 4 M) are more dispersed and more industrially useful than that which is treated at higher acid strength.

5

Kompozyty metaliczne wytwarzane metodą mechanicznej syntezy — przykład układu Al-Mg-ZrSi2

57%

Błaż L. , Kula A. , Sugamata M. , Kaneko J.

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2007

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tom R. 52, nr 11

823-828

PL

Przedstawiono skrótowy przegląd badań lekkich kompozytów metalicznych na osnowie Al i stopu Al-Mg wytwarzanych w ramach współpracy badawczej Nihon University w Tokio i Akademii Górniczo-Hutniczej. Od 1998 roku prowadzone są badania kompozytów zawierających 8÷19 % tlenków metali ze szczególnym uwzględnieniem wpływu temperatury na strukturę i własności materiału. Reakcja chemiczna w podwyższonej temperaturze może spowodować redukcję tlenków (Me-O) i zmiany struktury prowadzące do utworzenia tlenków aluminium lub złożonych faz Al(Mg)-O. Wyróżniono dwie podstawowe grupy kompozytów: (1) materiały, w których zredukowany metal (Me) jest praktycznie nierozpuszczalny w osnowie, oraz (2) materiały, w których uwolniony Me tworzy fazy międzymetaliczne z metalem osnowy. Istotnym problemem w produkcji kompozytów jest porowatość pojawiająca się przede wszystkim w wyniku reakcji chemicznej zależnie od lokalnej zmiany objętości składników i produktów reakcji w stanie stałym. W poszukiwaniu nowych składników umacniających kompozyty zwrócono uwagę na inne związki metali, które nie powodują nadmiernego utleniania osnowy, tak jak w wyniku redukcji tlenków. Wstępne badania zostały przeprowadzone dla kompozytu Al(Mg)-ZrSi2. Stwierdzono, że reakcja chemiczna między składnikami podczas wyżarzania lub odkształcania w podwyższonej temperaturze nie prowadzi do nadmiernych zmian silnie rozdrobnionej struktury materiału. Wielkość obserwowanych w osnowie dyspersyjnych tlenków typu Al-Mg-O nie ulega praktycznie zmianie nawet po przetopieniu kompozytu.

EN

Brief overview through research work on light-metal based composites developed at Nihon University, Tokyo and tested at AGH — University of Science and Technology according to bilateral research cooperation program is presented. Since 1998 a number of experiments were performed on aluminum and aluminum-magnesium based composites containing 8÷10 % other metal oxides in order to test the effect of temperature on the material structure and properties. Chemical reaction between the composite components at high enough temperature result in reduction of Me-oxides and development of very fine Al- and Al(Mg)-oxides within the matrix. In general, two groups of composites were distinguished: (1) composites containing Me-elements that are insoluble in Al-matrix and (2) composites containing Me-elements that create Al-Me or Al-Mg-Me intermetallics. Material porosity was found to depend on local volume contraction during chemical reaction as well as following intermetallic grains growth and related contraction/expansion effect. Searching for new hardening components was undertaken in order to select oxygen-free hardening components that avoid excessive oxidation of the matrix that result from chemical reaction at high temperature. Preliminary experiments were performed on Al(Mg)-ZrSi2 composite. It was observed that heavy refined structure of mechanically alloyed composite was practically unchanged during annealing even if some structural processes from chemical reaction between components were observed. Very fine Al(Mg)-O particles, that developed in the composite matrix, were practically stable in their size even if the material was re-melted above the matrix liquidus temperature.