材料期刊网

Cooling Efficiency of Laminar Cooling System for Plate Mill

ZHANG Dianhua , WANG Bingxing , ZHOU Na , YU Ming , WANG Jun

钢铁研究学报(英文版)

Heat transfer was researched from a perspective of the industry application. On the basis of the first law of thermodynamics, the cooling efficiency was deduced from the change of enthalpy inside hot plate. The relationship between the cooling efficiency and its influencing parameters was regressed from plenty of data collected from the worksite and discussed in detail. The temperature profiles resulting from the online model and the model modified by regressed formulas were presented and compared. The results indicated that the control accuracy of the modified model was increased obviously.

关键词: hot rolled plate;laminar cooling;cooling efficiency;temperature profile

Calculation Method of Optimal Speed Profile for Hot Plate During Controlled Cooling Process

WANG Bingxing , CHEN Xiaolin , TIAN Yong , WANG Zhaodong , WANG Jun , ZHANG Dianhua

钢铁研究学报(英文版)

The healthy and rapid development of the controlled cooling technology was hampered by the uneven cooling phenomenon. During the process of hot plate production, the homogeneous cooling along the length direction of plate was constrained by lots of factors. And because the speed was a flexible control parameter, the calculation method of optimal speed profile was developed based on the measured start cooling temperature and its matrix equation was solved by the Cholesky decomposition method. The optimal speed profile was used in online control system. As a result, the temperature distribution along the plate length direction was relatively uniform, and 95% of measured final cooling temperature difference from the target temperature 700 ℃ was controlled within ±20 ℃.

关键词: plate , controlled cooling , homogeneous cooling , speed profile , Cholesky decomposition method

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

Journal of Materials Research

The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.

关键词: room-temperature

Effect of interstitial hydrogen on cohesive strength of Al grain boundary with Mg segregation

材料科学技术（英）

The effect of interstitial hydrogen on the cohesion of the Al Sigma=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.

关键词: hydrogen;grain boundary;Al-Mg alloys;pseudopotentials;1st-principles

Effect of Interstitial Hydrogen on Cohesive Strength of Al Grain Boundary with Mg Segregation

Xiaoguang LIU , Xiaowei WANG

材料科学技术（英）

The effect of interstitial hydrogen on the cohesion of the Al ∑=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.

关键词: Hydrogen , null , null

First-principles study on the effect of Mn and N on the cohesion of a gamma-iron grain boundary

Physical Review B

By use of the linear-combination-of-atomic-orbital (LCAO) method for a cluster model, we studied the electronic structure of gamma-from Sigma 11 [1 (1) over bar0](11 (3) over bar) grain boundary doping with N and Mn atoms. The effect of the segregation on the cohesion of the grain boundary is investigated based on the Rice-Wang thermodynamic model. It is found that N could not only largely enhance the cohesion of the grain boundary but also eliminate the detrimental effect of Mn. The cosegregation effect of Mn and N on the cohesion of the grain boundary depends on where they segregate. Nitrogen could be reliably used in alloyed steels as an efficient strengthening element.

关键词: electronic-structure;phosphorus segregation;stainless-steel;embrittlement;austenite;nitrogen;boron;impurities;fracture;metals

高PPI ADS产品白Mura不良产生原理及改善研究

桑胜光 , 车晓盼 , 王嘉黎 , 郭红光 , 井杨坤 , 李泽 , 游伟

液晶与显示 doi:10.3788/YJYXS20163105.0435

现有传统TFT-LCD生产工艺中,Rubbing工艺在生产高PPI ADS产品的过程中,在改善Rubbing Mura不良时会使用H Cloth,但使用H Cloth Glass在经过Rubbing后ODF Rubbing Cleaner清洗时会出现白Mura不良.经过对白Mura不良Panel的微观解析,并结合H Cloth性质分析出白Mura不良是由于H Cloth自身的聚醋酸脂颗粒经过Rub-bing Cleaner聚集造成的.从Rubbing Cleaner清洗时改变Glass表面性质(醇类可以有效改变界面性质)入手,通过使用IPA对Glass进行清洗以改变聚醋酸脂疏水性,使得聚醋酸脂颗粒更易被Rubbing Cleaner清洗掉来改善白Mura不良,并结合生产实际定期对IPA进行更换以保持IPA浓度处于一个稳定的区间,使得高PPI ADS产品白Mura不良发生率由改善前的3.42％降低至改善后的0.11％,白Mura不良得到非常有效的改善.

关键词: 高PPI , 白Mura不良 , 聚醋酸脂 , 疏水性

First-principle study of electronic properties of Ti3Si1-xAlxC2 solid solutions

Journal of Physics and Chemistry of Solids

The layered ternary ceramics Ti3SiC2 and Ti3AlC2 are isostructural and can form Ti3Si1-xAlxC2 solid solutions combining the advanced properties of both compounds [H.B. Zhang, Y.C. Zhou, Y.W. Bao, M.S. Li, Improving the oxidation resistance of Ti3SiC2 by forming a Ti3Si0.90Al0.1C2 solid solution, Acta Mater. 52 (2004) 3631-3637; E.D. Wu, J.Y. Wang, H.B. Zhang, Y.C. Zhou, K. Sun, Y.J. Xue, Neutron diffraction studies of Ti3Si0.9Al0.1C2 compound, Mater. Lett. 59 (2005) 2715-2719; J.Y. Wang, Y.C. Zhou, First-principles study of equilibrium properties and electronic structure of Ti3Si0.75Al0.25C2 solid solution, J. Phys.: Condens. Matter 15 (2003) 5959-5968; Y.C. Zhou, J.X. Chen, J.Y. Wang, Strengthening of Ti3AlC2 by incorporation of Si to form Ti3Al1-xSixC2 solid solutions, Acta. Mater. 54 (2006) 1317-1322]. In the present work, the solid solutions of Ti3Si1-xAlxC2 (x = 0, 0.25, 0.33, 0.5, 0.67, 0.75, 1) are investigated by first-principle calculations based on pseudo-potential plan-wave method within the density functional theory framework. The results show that as Al content increases in the solid solution, all the bonds have weakened to certain extents, which lead to an unstable structure both energetically and geometrically. The calculated results are compared and discussed with the reported data for the Ti3Si1-xAlxC2 solid solutions. (c) 2007 Elsevier Ltd. All rights reserved.

关键词: ceramics;ab initio calculations;electronic structure;electrical;conductivity;oxidation behavior;mechanical-properties;ti3sic2;temperature;ti3alc2;air;si

GH4169合金高温力学行为本构建模及参数识别

魏洪亮 , 杨晓光 , 于慧臣

材料工程 doi:10.3969/j.issn.1001-4381.2005.04.011

针对涡轮盘用GH4169合金开展了高温下单调拉伸、对称循环及非对称循环的实验工作,结果表明,该材料具有比较明显的循环软化和平均应力松弛特性.采用带Ohno/Wang修正的Chaboche粘塑性理论本构方程,对其表现出的复杂力学现象进行本构建模,介绍了Levenberg-Marquadt非线性优化算法,结合材料实验数据并通过该算法识别了本构方程参数,将本构方程通过用户子程序嵌入到有限元软件ABAQUS中,对GH4169合金的上述实验现象进行了数值模拟,计算曲线与实验曲线取得了较好的一致性.

关键词: 循环软化 , 平均应力松弛 , 本构方程 , 参数识别