LI MeiyaShantou University
,
Shantou
,
Guangdong
,
ChinaCOWLAMNUniversity of Sheffield
,
Sheffield S3 7RH
,
UKCOCCOGUniversita di Sassari
,
via Vienna 2
,
07100 Sassari
,
Italy Manuscript received 10 May
,
1994
金属学报(英文版)
Small angle neutron scattering(SANS) technique has been used to investigate the Ni_(50)Mo_(50) system prepared by mechanical alloying(MA). Significant changes of the scattering intensity have been observed among the samples with different milling time.Interesting fractal-like behavior of the sample system have been found and attempts have been made to determine the fractal dimensions. It is expected that the fractal dimension can be related to the different stages of MA to some extent.
关键词:
mechanical alloying
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null
,
null
Journal of Physics-Condensed Matter
The structural and magnetic properties of RFe(10)Mo(2) and RFe(10)Mo(2)N have been studied by x-ray diffraction and high-field magnetization measurements on free-powder or magnetically aligned samples. The lattice of RFe(10)Mo(2) expands anisotropically upon nitrogenation and the volume of the unit cell increases by 2.9-4.0%. The rare-earth element dependence of lattice expansion is found to be just opposite to that of the Curie temperature. The saturation magnetization of RFe(10)Mo(2) increases after the introduction of nitrogen. The abnormally large values of magnetization for some heavy-rare-earth compounds imply that a non-collinear moment configuration in the absence of an external field may exist in these compounds.
关键词:
spin reorientation;ndfe10mo2n0.5;yfe12-xmox;field;nd;ho;mo
Acta Materialia
An analytical relationship between the ratio of hardness to reduced modulus H/E-r and the geometry of a residual indent is established based on the theories of depth-sensing indentation. Various material parameters, including elastic parameters, recovery deformation and energy-dissipation capacity, are uniquely determined by the value of H/E-r, so that they can be estimated from a residual indent trail. Thus, we are able to know what has happened in the material simply by analyzing or comparing residual trails on the material. The validity of this method has been confirmed by analyzing residual Vickers indents on quasi-plastic ceramic and brittle glass. In addition, it is demonstrated that the geometric constant epsilon in traditional nanoindentation theories is related to the proportional factor eta through the exponent of unloading curve m, i.e., epsilon = m (.) eta, where eta is defined by h(s) = eta (.) (h(m) - h(f)). (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词:
residual indent;Vickers indenter;property prediction;H/E-r ratio;depth-sensing indentation;instrumented indentation;mechanical-properties;nanoindentation;modulus;hardness;deformation;films;load;substrate
Journal of Magnetism and Magnetic Materials
Phase constitution and magnetic properties of Nd10Fe76B4M10 and Nd10Fe76B2M12 (M = Fe,Ti,V,Cr, Mn,Co and Al) alloys prepared by mechanical alloying and subsequent annealing have been systematically studied. It is found that the components of phases in the alloys critically depend on the additive transition metals M. In all the alloys, only the addition of Ti give significant enhancement to the permanent-magnetic properties. The increase of the Curie temperature in the Ti-doped alloys with an excessively low B content implies that part of the Ti atoms may occupy crystalline sites other than the Fe sites. In all the M additive alloys, with increasing content of the additive elements, the quantity of 1:7 phase increases and that of Nd2Fe14B-type phase decreases, (C) 2000 Elsevier Science B.V. All rights reserved.
关键词:
phase constitution;structure;magnetic properties;alloys;mechanical;alloying;nd;coercivity
ZHOU Yigang YU Hanqing ZENG Weidong Northwestern Polytechnical University
,
Xi'an
,
ChinaTANG Jialin China South Aviation Motive Power and Machinery Company
,
Zhuzhou
,
China professor
,
Department of Materials Science and Engineering
,
Northwestern Polytechnical University
,
Xi'an 710072
,
China
金属学报(英文版)
Effect of β-flecks on properties of tensile elongation and low cycle.fatigue life at room tern. perature for Ti-10V-2Fe-3Al alloy has been investigated.The cracks along initial β-grain boundaries in the β-fleck region may propagate to form intergranular brittle fracture.Under alternating load,the β-fleck often becomes a fatigue origin.While under higher strain,the cracks initiate and propagate to fracture early at the original β-grain boundaries in β-fleck region and at α-grain boundaries.
关键词:
Ti-10V-2Fe-3Al alloy
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null
,
null
,
null
M. H. Guo
,
D. C. Shao
,
Z. G Dong and J. C Yang National Key Laboratory Advanced Welding Production Technology
,
Harbin institute of Technology
,
Harbin 150001
,
China
金属学报(英文版)
Manuscript received 30 July 1999 Abstract The shielded metal arc welding (SMAW) of a manganese steel part as a crossing of railway track to a carbon steel part as the rails of the railroad is the welding of dissimilar steel. It are was known that it is not possible to the the rail of railroad directly to the cross- ing of railway track made from a steel containing about 14% of manganese (wt. ) because of so many differences between the two kinds of steels such as composition, microstructure,mechanical properties and weldability.A method was used to solve the problem by presetting an intermediate layer on each side of the joint and other special procedures were used.The result of test indicated that a good weld joint was obtained.
关键词:
high manganese steel
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null
,
null
,
null
L.L.Wang
,
L.H.Zhao
,
W.Y.Hu
,
X.L.Shu
,
X.J.Yuan
,
B.W.Zhang and X.Sheng Department of Applied Physics
,
Hunan University
,
Changsha 410082
,
China
金属学报(英文版)
Manuscript received 24 June 1999 The Fe Al P alloy deposits were plated on copper sheets by electroless plating. The change law of the deposition rate, composition, surface appearance and structure for the deposits was studied by changing the metallic salt ratios (AlCl 3/AlCl 3+FeSO 4), the concentration of metallic salt AlCl 3 and reductant NaH 2PO 2. The optimum plating bath was obtained. It was found that the choices of ligand and reductant were the key of increasing Al content for the deposits.
关键词:
electroless Fe Al P plating
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null
,
null
,
null
Journal of Materials Science
The solid-state reaction between crystalline nickel and pulverized melt-spun amorphous Fe78Si12B10 powders during mechanical milling has been investigated. For the powder mixtures with low nickel content (less-than-or-equal-to 30 at%), the reaction results in the production of a new amorphous phase. For the powder mixture with a high nickel content (up to 50 at%), crystalline gamma(Fe, Ni) and new amorphous phases are obtained. During the milling process, nickel atoms can dissolve in the amorphous matrix by diffusion due to severe deformation. The existence of ''free volume'' in the melt-spun amorphous phase may favour the diffusion of nickel atoms. At the same time, the elemental atoms (such as iron) in the amorphous phase may also dissolve into the nickel matrix. The amorphization between the amorphous and crystalline phases is attributed to the asymmetry of interdiffusion of the atoms in different matrices.
关键词:
metallic glasses;amorphization;alloys
