oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Synthesis, characterization and stability of amorphous alloys  [PDF]
Mini? Dragica M.
Science of Sintering , 2006, DOI: 10.2298/sos0601083m
Abstract: In this paper the results of chemical and electrochemical synthesis of Fe-P, Fe-W and Fe-Ni amorphous powders, investigations of their structural characteristics, stability and processes of their relaxation and stabilization during heating in the temperature range of 20-1000oC are presented. .
Synthesis and Characterization of Benzilate Esters as Aqueous Corrosion Inhibitors for Mild Steel and 2024, 6061, and 7075 Aluminum Alloys  [cached]
Volkan Cicek,Mehmet Ozdemir
International Journal of Chemistry , 2013, DOI: 10.5539/ijc.v5n1p26
Abstract: In this investigation, synthesis and characterization of environmentally friendly metallo-organic corrosion inhibitors for protection of mild steel and certain aluminum alloys are being sought to replace hexavalent chromium based corrosion inhibitors. For this reason, several corrosion inhibiting species such as benzilic acid and metal oxyanions were combined in a single compound with the general formula, (M)x(benzilicacid)y(M?aOb)z. First group of such compounds were synthesized in a similar study of the first author reported in another study with the title of “Synthesis and Characterization of Salts and Esters of Hydroxy Acids as Corrosion Inhibitors for Mild Steel and Aluminum Alloys” and this work aims to build on the success of those compounds since theoretically, there is no reason why benzilates cannot be good replacements for a-hydroxy acids such as gluconates. Additionally, benzilates are less soluble in general than hydroxyl acids, which could result in a corrosion inhibiting compound with an optimum window of solubility. Practical results have mostly proven the hypothesized advantages of benzilates correct and yielded that certain salts and esters of benzilates can be suitable corrosion inhibitors for certain metals and their alloys.
Synthesis and Characterization of Zinc Carboxylates as Aqueous Corrosion Inhibitors for Mild Steel and 2024, 6061, and 7075 Aluminum Alloys  [cached]
Volkan Cicek,Mehmet Ozdemir
International Journal of Chemistry , 2013, DOI: 10.5539/ijc.v5n2p7
Abstract: Synthesis and characterization of environmentally friendly metallo-organic corrosion inhibitors for protection of mild steel and certain aluminum alloys are being sought to replace carcinogenic hexavalent chromium based corrosion inhibitors. Given the toxicity and carcinogenicity of chromates, the purpose of this study is not just synthesizing any efficient corrosion inhibitors for certain alloys of certain metals to be applied in different environments, but also to find environmentally friendly corrosion inhibitors for successful chromate replacements. In this regard, the standard for an environmentally friendly inhibitor is considered as having acceptable or no toxicity compared to chromate inhibitors. Studying the reasons underlying the success of chromate inhibitors seems to be the first reasonable approach one might take before formulating chromate replacements. Therefore, synergistic combinations of carboxylic acids and zinc cation, which is well-known for its cationic inhibiting efficiency producing carboxylate salts of zinc with a general formula of (Zn) (hydroxyacid)2 are aimed to be synthesized and characterized. Practical results have proven the hypothesized advantages of zinc carboxylates correct and yielded that certain zinc carboxylates can be suitable corrosion inhibitors for certain metals and their alloys under specific circumstances.
Synthesis and Characterization of Heat Treated Cu-Al alloys for Energy Applications  [PDF]
J. Pereyra-Hernández, O. Ocampo, R. A. Falcon-Castrejon, I. Rosales-Cadena, J. A. Ruiz-Ochoa
Journal of Materials Science and Chemical Engineering (MSCE) , 2019, DOI: 10.4236/msce.2019.711003
Abstract: Three alloys with different atomic percent (at. %) Cu-Al were designed and synthetized, using an electromagnetic induction furnace system. Alloys were designed in a substitutional way, varying the Al content respect to Cu, from 10 to 50 at. %. Microstructure changes from dendritic structure to equiaxed grains depending the heat treatment. Hardness test evaluation has shown values in the order of 700 kg/mm2 which represents an increment of 600 percent, while compression tests have shown an important strengthening increment. Besides, electrical resistivity test was carried out, in order to analyze a future application in an electrochemical system, obtaining an improvement three times more in comparison with the unalloyed sample. Strengthening results were interpreted in terms of defects generation, caused by the thermal treatments.
Ab initio studies of CiCs and CiOi defects in Si1-xGex alloys
Si1-xGex合金半导体中CiCs和CiOi缺陷随Ge含量的变化

Yang Fu-Hu,Tan Jin,Zhou Cheng-Gang,Luo Hong-Bo,
杨福华
,谭 劲,周成冈,罗红波

中国物理 B , 2008,
Abstract: 采用从头计算(ab initio)的方法对Si和Si1-xGex合金半导体材料中CiCs缺陷的性质进行探讨,同时也对比调查了CiOi缺陷在Si和Si1-xGex合金中的性质. 在不同Ge含量的Si1-xGex
Surface and bulk characterization of molten In and In-Sn alloys  [cached]
Gauzzi F.,Giuranno D.,Montanari R.,Novakovic R.
EPJ Web of Conferences , 2011, DOI: 10.1051/epjconf/20111501007
Abstract: In this work a double contribution to the characterization of molten In and In-Sn alloys considered as main components of an important class of lead free solder materials is shown: the study of the influence of oxygen on the capillary phenomena and the XRD investigation of the structure of liquid in a range of temperatures around that of liquidus. The surface tension behaviour of In-Sn binary alloys at different compositions, in terms of effective oxygen pressure, were compared with the data of pure In and the theoretical predictions, revealing that the lower oxidizability of indium was shown to control indium–tin alloys with a tin content up to about 80 at% , due to the presence of the most volatile oxide In2O. From the XRD spectra the radial distribution functions (RDF) have been determined for each alloys. Experiments of High Temperature X-ray diffraction (HT-XRD) showed that atomic clustering forms in the melt immediately before the appearing of the first solid. The structure of clusters is correlated to that of solid.
Thermodynamic analysis and characterization of alloys in the Au-In-Sb system  [PDF]
Gomid?elovi? Lidija D.,?ivkovi? Dragana T.,Markovi? Desimir D.,Marjanovi? Bata R.
Hemijska Industrija , 2007, DOI: 10.2298/hemind0703157g
Abstract: The results of thermodynamic analysis and the characterization of alloys in the ternary system Au-In-Sb are presented in this study. Thermodynamic analysis was carried out by applying the Toop and Muggianu predicting methods in sections from the Au, In and Sb corner, respectively, with the following ratios 1:3 and 3:1. in the temperature interval from 873 to 1673 K. Characterization of the alloys in section Au-In-Sb was perfor-med using optical microscopy, SEM/EDX analysis and by hardness measurements of the investigated alloys.
Characterization of microstructure and properties of AlCuMg alloys  [PDF]
Zlati?anin Biljana V.,?uri? Stevan,Jordovi? Branka M.,Radonji? B.
Journal of Mining and Metallurgy, Section B : Metallurgy , 2003, DOI: 10.2298/jmmb0304509z
Abstract: The effect of magnesium content, in the interval range from 1 mass.% to 5 mass.%, on the microstructure and properties of aluminium - copper magnesium alloys was examined. The as-cast structure was modified by the addition of the AlTi5B1 to give alloys containing 0 to 0.25 mass. % titanium. Using X-ray powder diffraction we established that the tetragonal intermetallic compound Al2Cu and orthorhombic intermetallic compound Al2CuMg are formed across the whole range of magnesium additions. The effect of the magnesium and titanium content on the microstructure was monitored quantitatively. Using automatic image analysis we were able to measure the linear intercept grain size, the secondary dendrite arm spacing (DAS), the size of eutectic cells (Le), as well as the size distribution and volume fractions of the α-solid solution and the eutectic. In alloys containing high magnesium the average values of the DAS and grain size were found to decrease. Also, in alloys containing high magnesium the average values of the eutectic cell length and volume fractions of the eutectic were found to increase. The changes in chemical composition of the alloy cause changes in the structure that are reflected in the Brinell hardness and the compression strength. Compression strength and hardness increase with the content of magnesium and titanium.
Synthesis and characterization of hybrid nanostructures  [cached]
Taleb Mokari
Nano Reviews , 2011, DOI: 10.3402/nano.v2i0.5983
Abstract: There has been significant interest in the development of multicomponent nanocrystals formed by the assembly of two or more different materials with control over size, shape, composition, and spatial orientation. In particular, the selective growth of metals on the tips of semiconductor nanorods and wires can act to couple the electrical and optical properties of semiconductors with the unique properties of various metals. Here, we outline our progress on the solution-phase synthesis of metal-semiconductor heterojunctions formed by the growth of Au, Pt, or other binary catalytic metal systems on metal (Cd, Pb, Cu)-chalcogenide nanostructures. We show the ability to grow the metal on various shapes (spherical, rods, hexagonal prisms, and wires). Furthermore, manipulating the composition of the metal nanoparticles is also shown, where PtNi and PtCo alloys are our main focus. The magnetic and electrical properties of the developed hybrid nanostructures are shown.
Computational Investigation of Electronic and Optical Properties of Si, Ge and Si1-xGex Alloys Using the FP-LMTO Method Augmented by a Plane-Wave Basis
American Journal of Condensed Matter Physics , 2012, DOI: 10.5923/j.ajcmp.20120201.01
Abstract: An investigation into the structural, electronic and optical properties of Si, Ge, and Si1-xGex for different compositions was conducted using first-principles calculations based on density functional theory (DFT). The total energies were calculated within the full -potential linear muffin-tin orbital (FP-LMTO) method augmented by a plane-wave basis (PLW), implemented in Lmtar code. The effects of the approximations to the exchange-correlation energy were treated by the local density approximation (LDA). From our simulation results, it is found that the theoretical ground-state parameters, the band structure, the density of states (DOS), the chemical bonding and the optical properties agree well with the experiment and other theoretical calculations. The accuracies found from the present calculations allow us to describe the properties of the electronic as well as the optoelectronic devices based on the Si1-xGex alloy.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.