W.N.Liu 1)
,
M.N.Fang 2)
,
J.Xing 1) and Y.W.Liu 3) 1) Department of Mechanical Engineering
,
Changchun Institute of Optics and Fine Mechanics
,
Changchun 130022
,
China 2) Changchun Institute of Post and Telecommunications
,
Changchun 130022
,
China 3) Changchun Institute of Optics and Fine Mechanics
,
Changchun 130022
,
China
金属学报(英文版)
In this paper, we describe the laser heat-treating experiment results of three kind tool high-speed steel test samples. After laser quenching and tempering of three kinds of annealed tool high speed steel (W18Cr4V, W9Mo3Cr4V1, W6Mo5Cr4V2) test samples, we used microhardness-measure to test the samples and analyzed such problems as the hardness and depth of hardening quenching layer. Furthermore, after laser quenching and tempering of the quenched and three time tempered high speed steel (W18Cr4V) and its hardness analyzing, we got lase quenching's different results of the samples under different initial heat treating.
关键词:
high-speed steel
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null
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null
Journal of Physical Chemistry A
The density functional method with relativistic effective core potential has been employed to investigate systematically the geometrical structures, relative stabilities, growth-pattern behaviors, and electronic properties of small bimetallic M(2)Au(n) (M = Ag, Cu; n = 1-10) and pure gold Au(n) (n <= 12) clusters. The optimized geometries reveal that M(2) substituted Au(n+2) clusters and one Au atom capped M(2)Au(n-1) structures are dominant growth patterns of the stable alloyed M(2)Au(n) clusters. The calculated averaged atomic binding energies, fragmentation energies, and the second-order difference of energies as a function of the cluster size exhibit a pronounced even odd alternation phenomenon. The analytic results exhibit that the planar structure Ag(2)Au(4) and Cu(2)Au(2) isomers are the most stable geometries of Ag(2)Au(n) and Cu(2)Au(n) clusters, respectively. In addition, the HOMO-LUMO gaps, charge transfers, chemical hardnesses and polarizabilities have been analyzed and compared further.
关键词:
effective core potentials;transition-metal atoms;density-functional;theory;photoelectron-spectroscopy;molecular calculations;silver;clusters;fluorescence spectroscopy;polarizability;anions;adsorption
F. Shi
,
L.J. Wang
,
W.F. Cui
,
C.M. Liu
金属学报(英文版)
The precipitation behavior of M2N and the microstructural evolution in a Cr-Mn austenitic stainless steel with a high
nitrogen content of 0.43mass% during isothermal aging has been investigated using optical microscopy (OM), scanning electron
microscopy (SEM), and transmission electron microscopy (TEM). The aging treatments have led to the decomposition of nitrogen
supersaturated austenitic matrix through discontinuous cellular precipitation. The precipitated cells comprise alternate lamellae
of M2N precipitate and austenitic matrix. This kind of precipitate morphology is similar to that of pearlite. However, owing to the
non-eutectoidic mechanism of the reaction, the growth characteristic of the cellular precipitates is different from that
of pearlite in Fe-C binary alloys. M2N precipitate in the cell possesses a hexagonal crystal structure with the parameters a =
0.4752nm and c = 0.4429nm, and the orientation relationship between the M2N precipitates and austenite determined from the SADP is [0110]M2N∥ [101]γ，［2110］M2N∥ ［010］γ.
关键词:
austenitic stainless steel
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null
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null
自然科学进展﹒国际材料（英文）
The phase relations at the 600 degreesC and 700 degreesC isothermal sections of the ternary systems R-Co-B for R Nd, Pr and R = Sm, Cd respectively were summarized in this paper. For Rm+nCo5m+3nB2n, two new types of compounds R3Co13B2 ( R = Pr, Nd, Sm, Gd, Dy, Ho, Er, Y) (m = 2, n = 1) and R5Co19B6 (R = Pr, Nd) (m = 2, n = 3) were synthesized by utilizing the principle of structural combination. Their crystal* structures and easy magnetization direction were determined by X-ray powder diffraction, and structures were refined by the Rietveld method. The Curie temperature T-C, saturation magnetization M-s and anisotropic field H-A of the new compounds were measured using a vibrating-sample magnetometer, an extraction sample magnetometer and M(H) - H curves of samples in different magnetization directions respectively. The T-C and M-s of Rm+nCo5m+3nB2n increase with increasing values of m at a given n value. H-A increases with an increase in n when m is kept invariable. The effects of the substitution of Ni for Co on the magnetic properties of Nd13Co15-xNixB2 were also investigated. It was found that T-SR decreased monotonously as the concentration of Ni increased, and at x = 3 the easy magnetization direction becomes axial at room temperature. The relations between crystal structure and magnetic properties of Rm+nCo5m+3nB2n and the possible routes of synthesizing permanent magnetic materials are also discussed.
关键词:
R-Co-B ternary systems;R3Co13B2;P5Co19B6;crystal structure;magnetic;properties;co-b;phase relation;permanent-magnets;nd;borides;sm;gd;fe
Journal of Magnetism and Magnetic Materials
The electronic structures of two ferromagnetic polynuclear complexes, where the anionic [M(N-3)(2)(HCOO)(-)](n) chains with a 3-fold bridge of two end-on ( EO) azido and one sys-syn formato ligands are isolated by the cations of [(CH3)(2)NH2](+), have been studied using the full-potential linearized augmented plane wave method based on the density functional theory ( DFT). The result shows that spin populations in these two complexes are mainly distributed on the octahedron by four nitrogen atoms and two oxygen atoms of two formats at apical sites that surround the metal ions (M=Fe and Co). There are large and positive spin populations on metal ions, small and positive spin populations on the oxygen and nitrogen atoms of the anionic [M(N-3)(2)(HCOO)(-)](n) chains. Ferromagnetic coupling through the two EO-azido bridges in these two complexes has been mainly attributed to the spin delocalization, also with weak spin polarization effect. (C) 2007 Elsevier B.V. All rights reserved.
关键词:
DFT;electronic structure;ferromagnetic properties;ferromagnetic interaction;weak ferromagnetism;magnetic-properties;azido;copper(ii);compound;behavior;ligand
Journal of Physics-Condensed Matter
New compounds Pr3Co13B2 and Nd5Co19B6 have been synthesized successfully. They belong to the Rm+nCo5m+3nB2n family with m = 2, n = 1 and m = 2 and n = 3, respectively. Pr3Co13B2 adopts the hexagonal La3Ni13B2-type structure with lattice parameters a = 5.0672(3) Angstrom and c = 10.6850(6) Angstrom, while Nd5Co19B6 is isostructural to Lu5Ni19B6 With a = 5.1328(3) Angstrom and c = 16.6519(5) Angstrom. Magnetic measurements indicate that Pr3Co13B2 is ferromagnetic with a Curie temperature of 360 K. Its saturation magnetic moment at 5 K is 20.0 mu(B) fu(-1). Based on the results of the saturation magnetization, two kinds of Co sites with different magnetic moments are proposed. Pr3Co13B2 exhibits large uniaxial anisotropy with an anisotropy field of 90 A m(-1) at 5 K. The Nd5Co19B6 compound is ferromagnetic with a Curie temperature of 380 K. Its saturation magnetic moment and anisotropy field are 21.5 mu(B) fu(-1) and 340 A m(-1) at 5 K, respectively. No spin reorientation was detected from the temperature dependence of the magnetization of these compounds from 5 K to their Curie temperatures, and the behaviour of magnetocrystalline anisotropy was analysed using the single-ion model.
关键词:
anisotropy;system;field
Solid State Communications
First principles calculations have been performed to study the electronic structure and the ferromagnetic properties on the two chain compounds of [M(N-3)(2) (HCOO)] [(CH3)(2)NH2] (M = Fe and Co). The relative stability of the ground state, the density of states and the electronic band structure are examined. The results reveal that antiferromagnetism (AFM) state is the ground state and ferromagnetism (FM) state is the metastable one for both of them. The two compounds exhibit semiconductor character with small gap in the FM state, while metallic in the AFM state. In the FM state, the magnetic moments mainly arise from the Fe and Co ions with little contribution from the nearest-neighboring N and O atoms due to the hybridization between the Fe or Co 3d states and the nearest-neighboring N and O 2p states. (C) 2007 Elsevier Ltd. All rights reserved.
关键词:
organic magnet;magnetic semiconductors;first principles;electronic;structure;coupled organic ferromagnets;crystal-structure;magnetic-properties;complexes;azido;model
张忠义
,
沈雷军
,
李晓丽
,
韩莉
,
周永勃
,
陶冶
,
徐建华
,
黄艳
功能材料
采用高温固相反应合成(Ba,Mg,Sr)O·nAl2O3:M(n=4.6,M=Ce,Tb)发光材料.经X射线衍射分析,属六方晶系,与JSPDS标准卡完全一致.用同步辐射实验室真空紫外光谱站设备进行了光谱分析,在(Ba,Mg,Sr)O·nAl2O3:Ce(n=4.6)的激发光谱中,产生160nm和260nm的激发峰,分别由基质和铈离子的吸收引起的.在(Ba,Mg,Sr)O·nAl2O3:Tb(n=4.6)的激发光谱中,产生160、190和234nm的激发峰,其中160nm和234nm的激发峰是宽带峰,分别是由基质吸收和铽离子的4f-5d吸收引起的;190nm峰是铽离子的特征吸收引起的.由于铽离子的特征吸收和基质吸收产生较大的交迭,因此基质对铽离子具有能量传递.
关键词:
固相合成
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真空紫外光谱
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能量传递
Y.B. Hou
金属学报(英文版)
In this paper, the PMMA films doped with N,N'-diphenyl-N,N'-di(m-tolyl)-benzidineand rubrene were fabricated by spin coating, and the effect of photooxidation onthe photoluminescence of the doped PMMA thin films was investigated. The resultsshowed that under the irradiation of 350nm UV light, N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine can sensitized rubrene and results in the enhancement in the photooxrationof rubrene. The effect of photooxidation on the photoluminescence from rubrene w asmore obvious. Both lifetime measurement and in situ measurement of photolumines-cence showed that rubrene molecules exist in two chemical surroundings.
关键词:
photoluminescence
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null
