LI Lin
,
DE COOMAN B C
,
LIU Rendong
,
VLEUGELS J
,
ZHANG Mei
,
SHI Wen
钢铁研究学报(英文版)
A new type of transformation induced plasticity (TRIP) steel with not only high strength and high ductility but also superior welding and galvanizing properties was designed and developed recently. Low carbon and low silicon content were preliminarily selected with the aim of meeting the requirements of superior quality in both welding and galvanizing. Phosphorus was chosen as one of the alloying elements, because it could reduce carbon activity in cementite and increase the stability of austenite. In addition, the possibility of phosphorus segregating at grain boundary was also discussed by thermodynamics as well as kinetics. Phase diagram was estimated at high temperature and the composition of the steel was then selected in the hyperperitectic range to avoid problems, which might occur in sheet steel continuous casting. Phase diagram in the intercritical temperature was estimated for the steel to obtain the starting temperature of fast cooling. For understanding the minimum rate of fast cooling, pearlite growth kinetics was calculated with selfdeveloped diffusion coefficients of elements in grain boundary. Overaging temperature was determined through the calculation of T0 temperature by both equilibrium and paraequilibrium assumptions, which was different from the current determination, which is only based on an equilibrium estimation.
关键词:
TRIP steel;design;thermodynamics;kinetics;weldability;galvanization property
Materials Letters
Highly preferred (002) orientation transparent conductive Al-doped ZnO (ZAO) films were successfully prepared by de magnetron reactive sputtering from a Zn target mixed with Al of 2.0 wt.%. The film has a resistivity of 4.80 X 10(-4) n cm and a visible transmittance of as high as 90%. XPS analysis indicates Al-enrichment on the film surface. The asymmetry of Al 2p(3/2) XPS peak is resolved into two components: one centering at 72.14 eV attributed to metallic Al and the other having a binding energy of 74.17 eV due to oxidized Al. (C) 2001 Elsevier Science B.V. All rights reserved.
关键词:
Al-doped;ZnO;XPS;Al-enrichment;oxide thin-films;optical-properties;electrical-properties;rf;dc;transparent;deposition
Journal of Alloys and Compounds
Nd-Fe-(B.C) alloys have been synthesized by mechanical alloying and subsequent heat-treatment, with B4C as one of the starting materials. It is found that when the pure B4C is milled alone, it proves difficult to decompose. When the B4C compound is milled with Nd and Fe, the complete decomposition of B4C and the formation of Nd2Fe14(B,C) phase is observed. Furthermore, the competition between B and C atoms for entering the Nd2Fe14B lattice. the effects of the B4C content on the structure and the magnetic properties of Nd2Fe14(B,C)-based alloys are investigated. A coercivity as high as 18.3 kOe and the maximum energy product of 10.4 MGOe have been achieved for the Nd-Fe-(B,C) alloys. (c) 2005 Elsevier B.V. All rights reserved.
关键词:
permanent magnets;mechanical alloying;fe-c alloys;permanent-magnets;r2fe14c;nd
Kehai Li
材料科学技术（英文）
Modification of conventional gas metal arc welding (GMAW) process is of great potential to achieve high productivity with low cost and strong usability. Double-Electrode GMAW (DE-GMAW) is such a modified arc welding process which is formed by adding a bypass torch (gas tungsten arc welding torch) to a conventional GMAW system. The mechanism of metal transfer in DE-GMAW was proposed and verified in this paper. Experiments show that the critical current is decreased so that spray transfer can be obtained at a lower current level in DE-GMAW. Analysis of this significant change in metal transfer phenomena is conducted, and explanation is given out. It is found that the bypass arc in DE-GMAW lifts the anode point on the droplets such that the electromagnetic force becomes larger and squeezes the droplets so that spray transfer can take
place under welding current lower than that in conventional GMAW.
关键词:
Metal transfer
,
null
,
null
刘建功
,
殷小玮
,
成来飞
,
张立同
,
王琴
复合材料学报
为了降低液硅渗透法制备C／C—SiC复合材料中残留Si的含量，采用浆料浸渗结合液硅渗透工艺制备B12（C，Si，B）3改性C／C—SiC复合材料。通过分析不同比例B4C—Si体系在不同温度的反应产物，确定了B12（C，Si，B）3的生成条件。结果表明：B4C和Si在1300℃开始反应，生成少量B12（C，Si，B）3和SiC，且B12（C，Si，B）3的生成量随反应温度的升高而增加；当B4C和Si的摩尔比为3：1、反应温度为1500℃时，产物为B12（C，Si，B）3和SiC液硅渗透法制备的C／C—SiC复合材料相组成为非晶态C、β-SiC和B12（C，Si，B）3，未见残留Si。
关键词:
复合材料
,
C
,
C—SiC
,
B12(C，Si，B)3
,
浆料浸渗
,
液硅渗透
Physics Letters A
The magnetic properties of the mixed ferro-ferrimagnetic compounds with (A(a)B(b)C(c))(y)D, in which A, B, C and D are four different magnetic ions and form four different sublattices, are studied by using the Ising model. And the Ising model was dealt with standard mean-field approximation. The regions of concentration in which two compensation points or one compensation point exit are given in c-a, b-c and a-b planes. The phase diagrams of the transition temperature T-c and compensation temperature T-comp are obtained. The temperature dependences of the magnetization are also investigated. Some of the result can be used to explain the experimental work of the molecule-based ferro-ferrimagnet ((NiaMnbFecII)-Mn-II-Fe-II)(1.5) [Cr-III (CN)6] - zH(2)O. (C) 2003 Elsevier B.V. All rights reserved.
关键词:
mixed ferro-ferrimagnet;Ising model;four sublattices;phase diagram;transition temperature;compensation temperature;magnetic-properties;prussian blue;alloy
Journal of Alloys and Compounds
A model for diffusion is applied to the Ni-Al system to optimize the mobility parameters for the 132-b.c.c. phase by fitting the experimentally obtained diffusivities. In the model, the activation energy for diffusion is expressed as a function of the degree of ordering which is evaluated from thermodynamic data. The diffusivities, from the model are used to simulate diffusion experiments. The results are compared with experimental data and it is concluded that the model can yield satisfactory prediction. (C) 2007 Elsevier B.V. All rights reserved.
关键词:
intermetallics;diffusion;thermodynamic modeling;alloys;fe;interdiffusion;model
