材料期刊网

EVALUATION OF PERMEABILITY STABILITY OF SEVERAL AMORPHOUS FERROMAGNETIC ALLOYS

ZHANG Yanzhong Shanghai Iron and Steel Research Institute , Shanghai , China ZHANG Yanzhong Senior Engineer , Measuring and Testing Centre , Shanghai Iron and Steel Research Institute , Shanghai 200940 , China

金属学报(英文版)

The evaluation of the relative stability of initial permeability has been made of the pre-an- nealed amorphous ferromagnetic alloys Fe_(76)Si_(10)B_(14),Fe_(40)Ni_(38)Mo_4B_(18) and (Fe_(0.1)Ni_(0.35)Co_(0.55))_78Si_8B_(14) by the experimental values of average activation energy and fre- quency factors on the basis of the empirical expression deduced by experimental data of the kinetics of their permeability decay.Calculated results show that the relative stability of permeability is sufficient for practical uses in the temperature range within 100℃,although the permeability instability can not be substantially eliminated.In other words,the permeability decay is considerably small within a period of considerable length.

关键词: permeability decay , null , null

RESEARCH ON MEASURING METHOD OF THE THERMAL CONDUCTIVITY FOR HIGHLY POROUS MATERIALS

J Y Wu , Z.M. Tang , W Shi andR.Z. Wang (Institute of Refrigeration and Cryogenics Engineering , Shanghai Jiao Tong University , Shanghai 200030 , China)

金属学报(英文版)

A transient method with rectangular pulse heating has been developed to measure the thermal conductivity of highly porous materials such as activated carbon, zeolite and silica gel. By this method the thermal conductivity can be measured quickly and accu-rately. In this paper, a set of automatically controlled testing equiptnent is presented.The measuring method is analysed. The thermal conductivities of some samples, such as activated carbon and zeolite, are measured by the equipment. A group of useful data has been obtained.

关键词: thermal conductivity , null , null

Compensation Model For Shape Measuring of Cold Strip Rolling

YU Bing-qing , et al

钢铁研究学报(英文版)

The shape meter is interfered by some unavoidable factors in the process of cold strip shape measuring, so the measuring results can not reflect the ture shape and the measuring precision is low. In this paper, The influence of the measuring results is detailed analysed, which is influenced by the measuring error of strip edges、the transverse temperature difference of strip、the shape detection roller deflection and the shape of strip coil, The corresponding compensation models are established. And a cold strip mill is calculated as an example, gaines some disciplinarian cognitions.

关键词: cold strip;shape measuring;the compensation model

A CHALLENGE FOR BIAXIAL AND TRIAXIAL CREEP TESTING

M. Sakane (Department of Mechanical Engineering , Faculty of Science and Engineering , Ritsumeikan University , 1-1-1Nojihigashi Kusatsu-shi Shiga , 525-8577 , Japan)S. Mukai (Power Reactor and Nuclear Fuel Development Corporation , 4002 Narita-cho Oarai-cho Ibaragibun Ibaragi , 311-13 , Japan)

金属学报(英文版)

This paper describes new methods for biaxial and triaxial creep testing. Biaxial tension and triaxial tension creep testers were developed. The performance of the machines was described and some test results were discussed. Stress biaxiality had almost no effect on the creep deformation and Mises potential was suitable for describing the creep deformation under biaxial and triaxial stress states. Stress biaxiality had a small influence on prolonging creep rupture time under the constant Mises stress condition.A new triaxial tension creep testing method was discussed together with the shape of the triaxial creep specimen.

关键词: creep , null , null , null , null

Microsample tensile testing of nanocrystalline copper

Scripta Materialia

The tensile properties of nanocrystalline copper with grain sizes <100 nm produced by surface mechanical attrition treatment have been characterized using a microsample testing technique. The nanocrystalline copper exhibits a yield strength as high as 760 MPa, with a small elongation to failure. Factors leading to the high strength and low ductility are discussed. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.

关键词: nanocrystalline materials;strength;ductility;fracture;copper;mechanical-behavior;metals;microstructure;ductility;strength;fatigue;alloy;cu

A simple method for measuring tensile and shear bond strength of ceramic-ceramic and metal-ceramic joining

Materials Research Innovations

A simple method for measuring the ceramic-ceramic and metal-ceramic bond strength was presented, by which uniaxial tensile stress normal to the interface or shear stress in the interface can be produced using uniaxial compression load on a cross-bonded sample. Both tensile and shear bond strength were obtained by this testing technique for Ti3SiC2-TiO2 and Ti3SiC2-Al2O3 composite as well as for glued steel samples, respectively. The novel method provided a solution for determining bond strength in solid (especially brittle) materials, and it is also demonstrated as a useful method for evaluating the tensile and shear strength of various glues.

关键词: tensile bond-strength;shear bond-strength;cross-bonded sample;Ti3SiC2-Al2O3 joining;ceramic-ceramic joining;ceramic-metal joining;compressive load;system

A study on measuring the electromagnetic parameters of chiral materials

Journal of Physics D-Applied Physics

In this paper, a new method for simultaneously measuring the complex permittivity, complex permeability and complex chirality parameter of chiral materials in free space is presented. One has to measure the rotation angle, the axial ratio and the complex reflection coefficients of short-circuit (sample is backed with metal) and open-circuit (sample is not backed with metal) samples. Here, this method is named the free space short-circuit and open-circuit method.

关键词:

Deflection Compensation Model for Flatness Measuring Roll

LIU Jiawei , ZHANG Dianhua , WANG Junsheng , et al

钢铁研究学报(英文版)

In flatness of measurement system, the flatness roll deflection will have the disturbance to the flatness measuring signal. The flatness roller's stress is analyzed and the flatness roll deflection model is obtained by using the influence function method in this paper. The model is computed and gets the corresponding compensating curve. The results indicated that the compensated scheduled flatness is preferably accordant with the online rolling flatness, so the strip with good flatness can be obtained after the compensation

关键词: flatness measure roll;deflection;influence function method;compensation curve

Theoretical study of the electron paramagnetic resonance parameters and local structure for the tetragonal Ir(2+) centre in NaCl

Pramana-Journal of Physics

The electron paramagnetic resonance (EPR) parameters (the g factors, hyperfine structure constants and the superhyperfine parameters) for the tetragonal Ir(2+) centre in NaCl are theoretically investigated from the perturbation formulas of these parameters for a 5d(7) ion in tetragonally elongated octahedra. This impurity centre is attributed to the substitutional [IrCl(6)](4-) cluster on host Na(+) site, associated with the 4% relative elongation along the C (4)-axis due to the Jahn-Teller effect. Despite the ionicity of host NaCl, the [IrCl(6)](4-) cluster still exhibits moderate covalency and then the ligand orbital and spin-orbit coupling contributions should be taken into account. In addition, the theoretical EPR parameters based on the Jahn-Teller elongation show good agreement with the observed values.

关键词: Electron paramagnetic resonance;crystal- and ligand-field theory;Ir(2+);NaCl;transition-metal ions;epr spectroscopic investigations;atomic;screening constants;nuclear double-resonance;magnetic-resonance;superposition model;silver-halides;spin-resonance;scf functions;complexes

Theoretical studies of EPR parameters and microstructure of the rhombic Co2+-V-Ag centre in AgCl

Physica Status Solidi B-Basic Research

The perturbation formulae of EPR g-factors g(i) (i = x, y, z) and hyperfine constants Ai for a 3d(7) (Co2+) ion at a rhombic octahedral site in a crystal are established from a cluster approach. In these formulae, the contributions from the covalency effect, the configuration interaction and the rhombic crystal field are considered and the parameters used in the calculation of EPR parameters. except the core polarization constant x in the calculation of Al, can be estimated from the optical spectra and the structure data of the studied system. From these formulae, the EPR parameters g(i) and A(i) for the rhombic Co2+-V-Ag centre in AgCl are reasonably explained by considering suitable rhombic distortion and so the microstructure of this rhombic centre is obtained.

关键词: superposition model;crystals