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1.
V. V. Sagaradze N. V. Kataeva V. A. Zavalishin K. A. Kozlov V. V. Makarov A. R. Kuznetsov 《哲学杂志》2020,100(14):1868-1879
ABSTRACT The authors present the results of an investigation in Fe–Ni-Cr austenitic alloys of the low-temperature deformation-induced segregations of nickel that form in the micro regions being (i) located close to grain- and subgrain boundaries and (ii) characteristic of the concentration and magnetic inhomogeneities indicated by the appearance of a dark diffraction contrast at the electron diffraction patterns taken from these regions typical (at the same time) of an enhanced value of Curie temperature. The observed effects were connected with the micro distortions caused by the local change of lattice parameter because of an increase in nickel concentration, as well as in the result of a magnetostriction dilatation. Using methods of the X-ray energy dispersive spectroscopy (XEDS) and atomic-probe body-section radiography (tomography – APT) has made it possible to determine the borders of those regions of austenite that were characteristic of an enhanced concentration of nickel in the fields of the localisation of a deformation-induced segregation of nickel in the vicinity of grain (subgrain) boundaries of austenitic alloys of the types Fe–13Cr–30Ni and Fe–37Ni–3Ti. 相似文献
2.
3.
V. V. Kuznetsov N. V. Morozova V. N. Kudryavtsev 《Russian Journal of Electrochemistry》2006,42(6):665-669
Dependences of the current and the chemical composition of cathodic deposits on the electrolysis time are studied in an ammonia-citrate electrolyte for the deposition of a nickel-molybdenum alloy in potentiostatic conditions. At potentials less negative than ?0.93 V, no nickel-molybdenum alloy deposition occurs and in the course of electrolysis there is observed a decrease in the current, which is connected with the blocking of the electrode surface by the formed molybdenum oxides. In the region of potentials of deposition of a nickel-molybdenum alloy there is realized the following shape of a time dependence of the current. Within the first few seconds of the electrolysis process, the current somewhat decreases. Then there occurs its increase, which is connected with the alloy deposition on the cathode. In the course of electrolysis there occurs a decrease in the molybdenum content in the cathodic deposit. 相似文献
4.
根据Co P非晶态合金结构的短程有序和结构中可能存在P -P相互作用的实验事实 ,选择了单磷原子簇模型ConP(n =1~ 5 )和双磷原子簇模型ConP2 (n =1~ 4 ) ,用密度泛函理论方法对其进行计算 .结果表明 ,在单磷Co2 P( 2 ) 、Co3 P( 1) 及Co4P( 2 ) 模型体系中 ,Co原子供给P原子电子 ,与电负性规则一致 ,同时Co和P之间具较强化学作用 ,可以形成稳定的原子簇 ;而在双磷和单磷原子簇Co5P( 1) 模型体系中 ,形成的原子簇不稳定 ,采用单磷Co2 P( 2 ) 、Co3 P( 1) 及Co4P( 2 ) 模型能较好地反映Co P非晶态合金的结构特点 . 相似文献
5.
Non-isothermal short-range-order kinetics of binary alloys as influenced by solute-vacancy complexes
A model describing the roles of bound and unbound vacancies is proposed in order to predict defect decay and short-range-order
kinetics of quenched binary alloys during linear heating experiments. This is an alternative treatment of a previous approach.
The model has been applied to the differential scanning calorimetry (DSC) curves of Cu-5 at.% Zn quenched from different temperatures.
An expression to calculate the activation energy for migration of solute-vacancy complexes was also developed which make use
of DSC trace data. A value of 89.12±0.32 kJ mol-1 was obtained for the above alloy. The relative contribution of bound and unbound vacancies to partition of effective activation
energy corresponding to the ordering process as influenced by quenching temperature was also assessed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
A Raney-Ag catalyst was prepared by leaching out aluminium from a Raney Ag-Al alloy with NaOH solution. The kinetics of leaching
has been investigated in a stirred-batch-reactor at various temperatures by using alloy particles of different sizes. The
kinetic model best fitting the experimental results has been determined.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
7.
《Journal of solid state chemistry》2004,177(7):2366-2372
Proton exchange reactions have been performed on tetragonal tungsten bronze-like NaNbWO6 by using nitric acid as an exchanging agent. The characterization of the exchange reaction products has been made by means of chemical analysis, X-ray diffraction, thermal analysis, and IR spectroscopy. The exchange reaction takes place topotactically and the following formula is proposed for the obtained phase of variable composition: Na1−xHxNbWO6·yH2O (0<x?0.46 and 0?y?0.12). Impedance spectroscopy on the present proton exchanged samples indicated that these samples behaved as solid electrolytes under high humidity. As an example, the compound with the composition Na0.68H0.32NbWO6·0.1 H2O exhibits ionic conductivity of 8×10−3 and 1×10−2 S cm−1 at 70°C and 90°C, respectively. 相似文献
8.
用一个计算机控制的倒扭摆研究了快冷Fe71 Al2 9合金中的两个内耗峰 .在快冷的Fe71 Al2 9样品中分别在 180℃(P1 ) ,340℃ (P2 )和 5 10℃ (P3)出现了内耗峰 ,而在慢冷的Fe71 Al2 9样品中只发现了P3峰 .快冷样品中的P1 和P2峰在从 6 5 0℃冷却下来的测量过程中或在 35 0℃经过较长时间的时效后消失 ,其峰高随时效时间的增加而下降 ,直至消失 .P1 和P2 峰都有弛豫特征 ,它们的激活能分别为 :H1 =1.0 3± 0 .0 8eV(P1 峰 ) ;H2 =1.6 4± 0 .0 5eV(P2 峰 ) .P1 峰被认为是无序合金中Al原子在四面体点阵内的最近邻运动所引起 ,P2 峰则是无序合金中Al原子在四面体点阵内的次近邻运动所引起 相似文献
9.
Mössbauer investigations about iron atom redistribution in oxide films of zirconium alloys subjected to corrosion at 500°C in pure oxygen and water pair have been analysed. The alloys were also subjected to autoclave conditions at a pressure of 10.0 MPa and autoclave conditions at 350°C and at a pressure of 16.8 MPa, using distilled water and water with additives of lithium and fluorine. It is shown that, depending on the corrosion environment, various compounds of iron, such as α-Fe2O3, Fe3O4, and FeO, as solid solutions of iron in ZrO2 are formed in oxide films. 相似文献
10.
未来的照明光源--白光LED技术及其发展 总被引:22,自引:0,他引:22
白光是黑白和彩色摄像机的照明光源,可以替代白炽灯、荧光灯和高压气体放电灯等传统光源。介绍了白光LED技术的原理、特点、发展方向。 相似文献