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991.
992.
L.A.S. de Oliveira J.P. SinneckerR. Grössinger A. Pentón-MadrigalE. Estévez-Rams 《Journal of magnetism and magnetic materials》2011,323(14):1890-1894
We investigate the influence of Cu substitution, on the coercivity and magnetic viscosity, in the ternary system GdCo5−xCux (x=0, 0.5, 1, 1.5, 2 and 2.5) with different field sweep rates. All samples have been studied in the as cast state and crystallize in a single phase CaCu5 structure. With Cu addition, the coercivity was 10 times enhanced for x =1.5. The behavior of the coercivity Hc against field sweep rate, dH/dt, shows that the GdCo5−xCux system exhibits only a small magnetic viscosity effect, a desirable property for magnetic dynamic applications under high magnetic field. 相似文献
993.
Duygu Kocaefe Guvenc Ergin Yasar Kocaefe 《Surface and interface analysis : SIA》2008,40(12):1516-1522
Wettability of the granular bed media influences the efficiency of aluminum filtration. This project was undertaken to develop a method for determining the wettability of the granular media in order to evaluate its suitability for filtration. The wetting characteristics of different granular alumina particles by aluminum–magnesium alloys were studied using the infiltration method. The contact angles for rough as well as smooth surfaces were determined, and alumina particles were classified according to their wetting characteristics. The results were consistent and showed that it is possible to differentiate the wetting characteristics of different alumina samples with the infiltration method. A capillary model based on the energy balance was developed to analyze the experimental data. The model uses an average capillary pore size. For one type of alumina, this model was extended to carry out the analysis using a capillary pore size distribution. Similar results were found in both cases. This paper describes the experimental and modeling work, and the results are presented and discussed. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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995.
ZHU ChunLei WANG Qing ZHAO YaJun WANG YingMin QIANG JianBing & DONG Chuang Key Lab of Materials Modification School of Materials Science Engineering Dalian University of Technology Dalian China International Center for Materials Physics Chinese Academy of Sciences Shenyang 《中国科学:物理学 力学 天文学(英文版)》2010,(3)
The glass-forming ability and properties of Ni-based Ni-Fe-B-Si-Ta bulk metallic glasses are explored in this work. The alloy compositions are determined by using a combination of the cluster line approach, the multi-alloying strategy and the substitutions of similar elements. Bulk metallic glasses with diameters of 3 mm take shape at compositions formulated under the clus- ter-plus-glue-atom model [M9B]B~[(Ni1-xFex)7.71(Si0.66Ta0.34)1.29B]B0.94=(Ni1-xFex)70.5B17.7Si7.8Ta4, x=0.35–0.45, where the bracketed part is the cluster and the unbracketed part is the glue atoms. These alloys exhibit good magnetic properties. The maximum Is is found in the (Ni0.55Fe0.45)70.5B17.7Si7.8Ta4 alloy which reaches 0.51 T, with its Hc as low as 8.5 A/m. Interestingly, these alloys display dual glass transitions at (Ni0.65Fe0.35)70.5B17.7Si7.8Ta4, (Ni0.60Fe0.4)70.5B17.7Si7.8Ta4 and (Ni0.55Fe0.45)70.5B17.7- Si7.8Ta4 as unveiled by Temperature-Modulated Differential Scanning Calorimetry. 相似文献
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997.
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999.
J. Arghavani F. Auricchio R. Naghdabadi A. Reali S. Sohrabpour 《International Journal of Plasticity》2010
This paper presents a new phenomenological constitutive model for shape memory alloys, developed within the framework of irreversible thermodynamics and based on a scalar and a tensorial internal variable. In particular, the model uses a measure of the amount of stress-induced martensite as scalar internal variable and the preferred direction of variants as independent tensorial internal variable. Using this approach, it is possible to account for variant reorientation and for the effects of multiaxial non-proportional loadings in a more accurate form than previously done. In particular, we propose a model that has the property of completely decoupling the pure reorientation mechanism from the pure transformation mechanism. Numerical tests show the ability to reproduce main features of shape memory alloys in proportional loadings and also to improve prediction capabilities under non-proportional loadings, as proven by the comparison with several experimental results available in the literature. 相似文献
1000.
S. Banerjee 《Phase Transitions》2013,86(1-4):389-406
Abstract The continuous ordering process can be viewed as a development and a gradual amplification of concentration modulations with wave lengths of the order of a few lattice spacings. How the development of different concentration modulaltions leads to different superlattice structures in cubic systems is explained with the help of some illustrative examples. The importance of concentration modulations with special point wave vectors in the stability of the various coherent superlattice structures is discussed. Experimental evidences for such continuous ordering is cited from recent results on ordering in Ni-Mo alloys. The evolution of ordering in some systems can also be viewed as progressively tiling the disordered lattice by superlattice tiles. When more than one type of coherent superlattice tiles compete, juxtaposition of different types of tiles can occur during the course of ordering. The transitional states between the short range and the long range ordered Ni-Mo alloys indeed exhibit such structures where different types of superlattice tiles decorate the fcc lattice. The role of special point concentration waves in the development of such structures will be discussed in relation to the secondary ordering processes involving two perpendicular ?1 ½ 0? waves and a combination of an ?1 ½ 0? and an appropriate ?100? wave. 相似文献