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Regularities of formation of ternary intermetallic compound between transition elements

Lixiu YAO , Jie YANG , Chenzhou YE , Nianyi CHEN

材料科学技术(英文)

Four parameters, phi (electronegativity), n(ws)(1/3) (valence electron density in Wagner-Seitz cell), R (Pauling's metallic radius) and Z (number of valence electrons in atom), and the pattern recognition methods were used to investigate the regularities of formation of ternary intermetallic compounds between three transition elements. The obtained mathematical model expressed by some inequalities can be used as a criterion of ternary compound formation in "unknown" phase diagrams of alloy systems.

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Regularities of formation of ternary intermetallic compounds between one transition element and two non-transition elements

Lixiu YAO , Nianyi CHEN , Jie YANG

材料科学技术(英文)

The pattern recognition methods and a four-parameter model, Eased on extension of Miedema's cellular model of alloy phases, are used to study the regularities of formation of ternary compounds between one transition element (T) and two non-transition elements (N, N') (T-N-N' system). The influences of phi (electronegativity), n(ws)(1/3)(valence electron density in Wagner-Seitz cell), R(Pauling's metallic radii) and Z (number of valence electrons in atom) on the formation of the ternary intermetallic compounds were investigated.

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Comparison of Inconel 625 and Inconel 600 in resistance to cavitation erosion and jet impingement erosion

Nuclear Engineering and Design

Liquid droplet erosion (LDE), which often occurs in bellows made of nickel-based alloys, threatens the security operation of the nuclear power plant. As the candidate materials of the bellows, Inconel 600 and Inconel 625 were both tested for resistance to cavitation erosion (CE) and jet impingement erosion (JIE) through vibratory cavitation equipment and a jet apparatus for erosion-corrosion. Cumulative mass loss vs. exposure time was used to evaluate the erosion rate of the two alloys. The surface and cross-sectional morphologies before and after the erosion tests were observed by scanning electron microscopy (SEM), the inclusions were analyzed by an energy dispersive spectroscopy (EDS), and the surface roughness was also measured by surface roughness tester to illustrate the evolution of erosion process. The results show that the cumulative mass loss of CE of Inconel 625 is about 1/6 that of Inconel 600 and the CE incubation period of the Inconel 625 is 4 times as long as that of the Inconel 600. The micro-morphology evolution of CE process illustrates that the twinning and hardness of the Inconel 625 plays a significant role in CE. In addition, the cumulative mass loss of JIE of Inconel 625 is about 2/3 that of Inconel 600 at impacting angle of 90 degrees, and almost equal to that of the Inconel 600 at impacting angle of 30 degrees. Overall, the resistance to CE and JIE of Inconel 625 is much superior to that of Inconel 600. (C) 2010 Elsevier By. All rights reserved.

关键词: stress-corrosion cracking;aluminide intermetallic alloys;high-purity;water;mechanical-properties;crevice corrosion;solid particles;wear;behavior;microstructure;deformation;steam

Cavitation erosion and jet impingement erosion mechanism of cold sprayed Ni-Al(2)O(3) coating

Nuclear Engineering and Design

A composite coating was deposited on Inconel 600 substrate by cold spray method using pure Ni powder (60 wt.%) blended with alpha-Al(2)O(3) (40 wt.%) as feedstock. It is expected to be applied to repair the bellows eroded by the liquid droplet erosion (LDE). Microstructure of the coating was observed using optical microscope (OM) and scanning electron microscopy (SEM). Microhardness of the coating was determined by Vickers hardness tester. Cavitation erosion (CE) experiments were carried out in the distilled water. Jet impingement erosion (JIE) experiments were performed in slurry containing 1 wt.% quartz particle with the flow velocity of 15 m/s at impingement angles of 30 degrees, 60 degrees and 90 degrees, respectively. Cumulative mass loss vs. testing time was used to evaluate the erosion rate of the coating. The erosion mechanism was analyzed by OM, SEM, X-ray diffraction (XRD) and the microhardness measurement. The results show that the composite coating has compact microstructure and relatively high hardness. The resistance to CE of the coating is not as good as that of Inconel 600 substrate due to the weak bonds of the Al(2)O(3) particles. However, the results of the JIE test indicate that the slurry erosion resistance of the coating is better than that of Inconel 600 at the impact angles of 30 degrees and 60 degrees, but not at the normal impact angle. (C) 2011 Elsevier B.V. All rights reserved.

关键词: large powder particles;composite coatings;slurry erosion;kinetic;spray;liquid impact;alloy;microstructure;steels;deposition;resistance

Modification of Analytical Expression of Electron Dynamical Diffraction

Canying CAI , Qibin YANG , Hongrong LIU

材料科学技术(英文)

Assuming that the wave function , the Schrodinger equation can be written as . Neglecting the last two terms, an analytical expression of electron dynamical diffraction was derived by Qibin YANG et al. In this paper, the analytical expression is modified by further considering the second-order differential term . When the accelerating voltage is not very high, or the sample is not very thin, the reciprocal vector ɡ is large, the modification of the second-order differential is necessary; otherwise it can be neglected.

关键词: Electron dynamical diffraction , null

1998 COMPREHENSIVE TABLE OF CONTENTS

中国腐蚀与防护学报

N。1Atmospheric Corrosivlty for Steels………………………………………………… .LIANG Caideng HO[I i。-tat(6)Caustic Stress Corrosion Cr。king of Alloy 800 Part 2.The Effect of Thiosul执e……………………………………… KONG De-sheng YANG Wu ZHAO Guo-zheng HUANG De.ltL。ZHANG Yu。。he CHEN She。g-bac(13)SERS slid E16CttOCh6iniC81 Stlldy Of Illhibit1Oli M6ch&tllsth Of ThlollY68 Oil ITOll ID H....

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(1-x)Bi4Ti3O12-xSrBi2Nb2O9铋层状铁电陶瓷结构与性能研究

涂娜 , 江向平 , 李小红 , 傅小龙 , 杨帆

人工晶体学报

采用传统固相法制备了(1-x)Bi4Ti3 O12-xSrBi2 Nb2 O9(BIT-SBN,x=0,0.025,0.050,0.100,0.150,0.200)铋层状无铅压电陶瓷.系统研究了SrBi2 Nb2 O9掺杂对Bi4Ti3 O12基陶瓷物相结构、微观结构以及jie电性能的影响.结果表明:所有陶瓷样品均为单一的铋层状结构;当SBN掺量为0.100时,样品具有最佳的电性能:d33=21 pC/N,相对密度ρ =98.1%,机电耦合系数kp=8.26%,εr=220,介电损耗tanδ =0.29%,剩余极化强度Pr=9.128 μC/cm2,Tc=594℃.同时,SBN的引入增强了样品的抗老化性和热稳定性.

关键词: Bi4Ti3O12 , SrBi2Nb2O9 , 铋层状 , 铁电陶瓷 , 介电性能

连铸结晶器弯月面处保护渣的流动行为

颜慧成 , 郭征 , 张孟亭 , 张洪平

钢铁研究学报

引入变量m(冲量密度)和Yang-Mills型规范变换m=u+gradφ,将原始变量的N-S方程转化为规范-不变量形式,用自由质点法处理Voronoi元,对连铸结晶器弯月面处保护渣流动行为进行数学模拟.输出振动周期内的动态流场,然后结合一组试验数据进行计算,计算结果与实际情况相吻合,进而讨论了渣圈对液渣流动行为的影响,为研究结晶器弯月面处保护渣的行为和铸坯振痕的形成提供了一定的依据.

关键词: 连续铸钢 , 保护渣 , 流动行为 , 数学模拟

快速床动力学统一模型-由A型噎塞向C型噎塞的连续转变Ⅰ:模型构建

章明川 , 张楚 , 林郁郁 , 徐旭常

工程热物理学报

根据快速流化床的基本流动特性、A 型噎塞和 C 型噎塞的特征与定义,建立了一个统一,自恰的快速床模型一分相共存模型.模型以 A 型噎塞的修正Yang公式为‘本构方程',合理预报了快速床的最小固体流率Gsm,以及在固体流率不变的条件下降低操作气速时床层由A型噎塞向C型噎塞的连续过渡.模型中的稀相有效气流速度函数幂次n为可调参数,根据 C 型噎塞速度预报的Yousfi and Gau公式,初步确定模型参数n=4.

关键词: 快速流态化 , 噎塞速度 , A 型噎塞 , C 型噎塞 , 分相共存模型

NCl(a1 △)泵浦碘原子化学激光综述及可行性分析

多丽萍 , 李国富 , 李健 , 闵祥德

量子电子学报 doi:10.3969/j.issn.1007-5461.2001.05.001

自1990年Bower和Yang报告了NCl(a1△)/I的传能,引起了人们的极大关注.由NCl(a1△)泵浦I原子的全气相化学激光器能否产生和放大以及该体系的相关动力学的研究近几年也广泛展开.本文在综述了有关NCl(a 1△)及其与I的传能和发展现状基础上,理论上进行了分析和计算.最后对NCl(a 1△)泵浦I化学激光器可行性做了展望并提出具体探索和解决的途径.

关键词: 亚稳态NCl(a1△) , I原子化学激光

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