Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Corrosion behaviour of binary Mg-Li alloys for plastic forming  [PDF]
A. Bia?obrzeski,K. Saja,M. ?mudzińska
Archives of Foundry Engineering , 2011,
Abstract: The paper outlines the course of corrosion processes in magnesium and Mg-Li alloys. The methodology of corrosion studies of alloys for plastic forming and their chemical composition as well as micrographs of alloys intended for research are presented.
Studies of corrosion behaviour in acid environment of binary Mg-Li alloys for plastic forming
A. Bia?obrzeski,K. Saja,M. ?mudzińska
Archives of Foundry Engineering , 2011,
Abstract: The article discusses studies and corrosion tests of binary Mg-Li alloys for plastic forming examined in an acid medium (5% HCl solution)for the time of 0-144 hours. In short it can be stated that corrosion of the examined Mg-Li alloys in 5% HCl solution proceeded in a similarmode in all the studied alloys, regardless of the lithium content.
Studies of corrosion behaviour in alkaline environment of binary Mg-Li alloys for plastic forming
A. Bia?obrzeski,K. Saja,M. ?mudzińska
Archives of Foundry Engineering , 2011,
Abstract: The article discusses studies and corrosion tests of binary Mg-Li alloys for plastic forming examined in an alkaline medium (5% NaClsolution) for the time of 0-144 hours. In short it can be stated that the increase of Li content in magnesium alloys from 3% to 9% increasesthe corrosion resistance of alloy (the lowest susceptibility to corrosion in NaCl solution showed Mg- Li9 alloy). Increasing the content ofLi in alloy to over 9% resulted in a significant increase of the susceptibility to corrosion.
Microscopic dynamics in liquid binary alloys: orbital-free ab-initio molecular dynamics studies  [cached]
Condensed Matter Physics , 2008,
Abstract: We report an ab-initio molecular dynamics study on the collective excitations in several s-p bonded liquid binary alloys. Results are reported for the Li-Na, Li-Mg, K-Cs and Li-Ba liquid alloys at different concentrations, which display mass ratios ranging from ≈3 for Li-Na to ≈20 for Li-Ba, and varying ordering tendencies, ranging from strong homocoordinating in Li-Na to mildly heterocoordinating for one concentration of Li-Ba. The study has been carried out using the orbital free ab-initio molecular dynamics method, combined with local ionic pseudopotentials constructed within the same framework. We analyze the dependence of the collective modes on the concentration and the mass ratio of the alloy, finding a common behaviour for all systems notwithstanding the different ordering tendencies.
YAO Daping HU Zhuangqi ZHANG Yun SHI Changxu Institute of Metal Research,Academia Sinica,Sheyang,China Institute of Metall Research,Academia Sinica,Shenyang,China,
YAO Daping HU Zhuangqi ZHANG Yun SHI Changxu Institute of Metal Research
,Academia Sinica,Sheyang,China Institute of Metall Research,Academia Sinica,Shenyang,China

金属学报(英文版) , 1990,
Abstract: Studies were carried out on the precipitation in two sets of binary Al-Li alloys by means ofhardness tests,DSC analyses and TEM observations.When the alloys were aged for constanttime,a peak appeared on the plot of temperature dependence upon their hardness in the rangeof low temperatures,and the endothermic dissolution peak was quite distinct on the DSCcurve also at low temperatures.These are believed that an Li-rich GP zone formed in the al-loys aged at low temperatures,but no more GP zone if aging at elevated temperatures.Thehardness of the alloys raises rapidly with coarsening of δ′-phase grains.The two endothermicpeaks of δ′ dissolution on the DSC curve relate to the structural adjustment at twice of the δ′precipitation.The equilibrium δ-phase,being of higher thermal stability,nucleates and growsdirectly from the supersaturated solid solution with the aid of the gram boundary.
Microstructure and properties of Mg-Al binary alloys  [PDF]
ZHENG Wei-chao,LI Shuang-shou,TANG Bin
China Foundry , 2006,
Abstract: The effects of different amounts of added Al, ranging from 1 % to 9 %, on the microstructure and properties of Mg-Al binary alloys were investigated. The results showed that when the amount of added Al is less than 5%, the grain size of the Mg-Al binary alloys decreases dramatically from 3 097 μm to 151 μm with increasing addition of Al. Further addition of Al up to 9% makes the grain size decrease slowly to 111 μm. The α-Mg dendrite arms are also refined. Increasing the amount of added Al decreases the hot cracking susceptibility of the Mg-Al binary alloys remarkably, and enhances the micro-hardness of the α-Mg matrix.
S. K. Chakrabarti
International Journal of Chemical Sciences and Research , 2011,
Abstract: There are a large number of binary liquid alloys which exhibit interesting behaviour as a function of concentration as regards the thermodynamic properties. In the present work two binary molten alloys are considered e.g. Cu-Sn and Cd-Mg in which complexes are formed as revealed from their liquidus lines. The former alloy shows anomaly in its thermodynamic properties of mixing. On the other hand, the alloying behaviour of the latter one is symmetric around the equi-atomic composition. But so far as entropy of mixing (SM) is concerned copper-tin liquid alloy also shows symmetry about equi-atomic composition. Here the quasi-lattice chemical model has been used for computation of the values of SM of these alloys for different concentrations of the ingredients. For each alloy calculations are started with the expression for excess free energy of mixing (xsGM ) according to this model and the values of different interaction parameters (ωij) are primarily found out from the experimental data of xsGM for several concentrations of the constituent species. Putting these values of ωijthe free energy of mixing (GM) is calculated for various concentrations and then compared with its observed values both numerically and graphically. Accordingly, a modified set of values of ωij has been considered and the calculations are repeated. In this way by the method of successive approximation the values of the interaction parameters have been ascertained and thereby the set of values of GM. Similarly, the expression for heat of mixing (HM) is taken into account and the temperature derivatives of the said interaction parameters are ascertained from the observed values of HM for different concentrations by such successive approximation method. Finally, SM has been computed on using the standard thermodynamic relation from the sets of values of GM and HM thus obtained. The results explain the observed symmetry in the entropy of mixing of the present alloys.
Surface Phases in Binary Liquid Metal Alloys  [PDF]
Holger Tostmann,Elaine DiMasi,Oleg G. Shpyrko,Ben M. Ocko,Peter S. Pershan,Moshe Deutsch
Physics , 2004,
Abstract: Surface sensitive x-ray scattering techniques with atomic scale resolution are employed to investigate the microscopic structure of the surface of three classes of liquid binary alloys: (i) Surface segregation in partly miscible binary alloys as predicted by the Gibbs adsorption rule is investigated for Ga-In. The first layer consists of a supercooled In monolayer and the bulk composition is reached after about two atomic diameters. (ii) The Ga-Bi system displays a wetting transition at a characteristic temperature T_w~220 C. The transition from a Bi monolayer on Ga below T_w to a thick Bi-rich wetting film above T_w is studied. (iii) The effect of attractive interactions between the two components of a binary alloy on the surface structure is investigated for two Hg-Au alloys.
Phonon Dispersion in Equiatomic Li-Based Binary Alloys
Aditya M Vora,

中国物理快报 , 2008,
Abstract: The computations of the phonon dispersion curves (PDC) of four equiatomic Li-based binary alloys, namely Li0.5Na0.5, Li0.5K0.5, Li0.5Rb0.5 and Li0.5Cs0.5, to second order in the local model potential is discussed in terms of the real-space sum of Born von Karman central force constants. Instead of the concentration average of the force constants of metallic Li, Na, K, Rb and Cs, the pseudo-alloy atom (PAA) is adopted to compute directly the force constants of four equiatomic Li-based binary alloys. The exchange and correlation functions due to Hartree (H) and Ichimaru--Utsumi (IU) are used to investigate the influence of screening effects. The phonon frequencies of four equiatomic Li-based binary alloys in the longitudinal branch are more sensitive to the exchange and correlation effects in comparison with the transverse branches. However, the frequencies in the longitudinal branch are suppressed due to IU-screening function than the frequencies due to staticH-screening function.

LIU Zhiyi,

金属学报 , 1984,
Abstract: A proposal was made of the increasing tendency of amorphous formation of the binary transition metal alloys caused by the incongruent-and congruent-melting compounds of lower melting temperature on the basis of synthesis of the previous experimental data, including the author's. The effects of crystalline structure, atomic radius difference, electronic structure and electro-negativity difference of eIements were discussed. An empirical approach to the formation of binary amorphous alloys by liquid quenching was summarized. Thus, certain new alloy systems, e.g., Ti-Pd, La-Si, Zr-Ga, Hf-Pd, etc. may be developed.
Page 1 /100
Display every page Item

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