材料期刊网，材料期刊，材料类期刊，材料期刊投稿

Numerical and Experimental Studies of Substrate Melting and Resolidification during Thermal Spraying

H.Zhang , G.Wei , L.Zheng , L.Li , X.Y.Wang , A.Vaidya

A good understanding of melting and resolidification of the substrate will help us to achieve better bonding. A numerical model is developed to investigate the solidification of the droplet, and melting and resolidification of the substrate. The molybdenum powder spraying onto three different substrates: a stainless steel, brass (70%Cu) and aluminum by atmospheric plasma spraying has been investigated. The maximum melting depth of the substrate has been measured and compared with the numerical prediction. Experimental results show that the material properties of the splat and substrate and melting temperature of the substrate play the important roles on substrate melting. A dimensionless parameter, temperature factor, has been proposed and served as an indicator for substrate melting.

关键词: Thermal spraying , null , null , null , null

Effect of Li and Ti Additions on L■α(Al)+Mg_2Si Pseudobinary Eutectic Reaction

Shengxu ZHAO , Shunpu LI , Deqian ZHAO , Mingxiang PAN and Xichen CHEN(Institute of Physics , Chinese Academy of Sciences , Beijing 100080 , China)

材料科学技术（英文）

Effect of Li and Ti additions on Lα(AI)+Mg2Si pseudobinary eutectic reaction in ternary Al-Mg-Si system has been investigated by thermoanalysis, directional solidification and metallographic techniques in this study. It has been found that Li addition causes decreasing of the volume fraction of Mg2Si, while a little amount of Ti causes to increasing, which is of a great importance to the adjustment of phase constitution and alloy properties. Doping components have little influence on the eutectic temperature.

关键词:

L12-Al3Li金属间化合物点缺陷浓度的第一原理计算

孙顺平 , 李小平 , 于赟 , 卢雅琳 , 臧冰 , 易丹青 , 江勇

中国有色金属学报

运用第一原理平面波赝势方法计算L12-Al3Li金属间化合物点缺陷的形成焓,并结合Wagner–Schottky模型,研究L12-Al3Li金属间化合物在523、673、823和1000 K时点缺陷浓度与成分之间的关系.结果表明:在这4个温度下,L12-Al3Li金属间化合物中Al空位浓度最小,Li空位浓度次之,Al反位和Li反位的缺陷浓度较大.Al反位和Li反位缺陷浓度在理想金属间化合物Al3Li化学计量比成分处基本相同,不过两种反位的缺陷浓度随着合金成分相对于化学计量比成分的偏离而变化显著,在富Al端Al反位缺陷浓度较大,在富Li端Li反位缺陷浓度较大.运用Arrhenius方程计算点缺陷的有效形成焓,结果显示Al反位和Li反位的有效形成焓较小且基本相同,Li空位次之,Al空位最大.

关键词: Al3Li金属间化合物 , 第一原理计算 , 点缺陷浓度 , 形成焓 , Wagner–Schottky模型

316L不锈钢在熔融LiCl-3%Li2O中的腐蚀行为

常晓亮 , 王旭 , 王兰芳 , 张俊善 , 祝美丽

机械工程材料 doi:10.3969/j.issn.1000-3738.2007.04.004

采用浸没法腐蚀试验研究了在真空及空气两种环境中316L不锈钢在700℃熔融LiCl-3%Li2O混合熔盐中的热腐蚀行为.结果表明:316L不锈钢在两种条件下的腐蚀产物均为LiCrO2,腐蚀质量损失均随时间的延长而增大;在真空条件下腐蚀质量损失明显小于空气条件下,氧分压对腐蚀行为的影响显著.

关键词: 316L不锈钢 , 熔盐 , 腐蚀

THE SOLIDIFICATION BEHAVIOR OF 8090 AL-LI ALLOY

Metallurgical Transactions B-Process Metallurgy

In this work, the solidification and segregation behaviors of 8090 Al-Li alloy have been investigated with differential thermal analysis (DTA) and the metallographic-electron microprobe method. The results show that 8090 Al-Li alloy has a much more complex solidification path than Al-Li binary alloy due to the addition of many alloying elements and the presence of impure elements. Solidification begins at about 635-degrees-C with the reaction of L --> alpha-Al + L', and this reaction goes on to termination. The alloying element Cu and impure elements Fe and Si have a strong segregation tendency. During solidification, Cu segregates to the interdendrite and finally forms alpha-Al + T2 eutectic. As a result, the solidification temperature range is greatly extended. Iron and Si form the insoluble constituents Al7Cu2Fe, AlLiSi, etc., although their concentrations in the alloy are quite low. With the increase of Fe content, there is a eutectic reaction of alpha-Al/Al3Fe at about 595-degrees-C. The formation of insoluble constituents is influenced by both concentrations of impure elements in the alloy and the cooling rate.

关键词: fracture-behavior;phase-equilibria;cu alloys;microstructure;lithium;zr

Li对Al-Zn-Mg-Cu系合金时效早期原子聚集行为的影响

魏芳 , 白朴存 , 周铁涛 , 刘培英 , 张永刚 , 陈昌麒

航空材料学报 doi:10.3969/j.issn.1005-5053.2004.01.006

针对Al-Zn-Mg-Cu-Li合金时效早期出现的硬度快速上升现象,用L-J势函数计算了该合金各种原子间、原子与空位间的相互作用势.结果表明:在Al-Zn-Mg-Cu合金中,以Mg/v聚集为主,还有Zn/v,Cu/v,Zn/Mg的复合聚集;加入较高量的Li以后,则以Li/v聚集为主,几乎没有Zn/Mg聚集形式.

关键词: Al-Zn-Mg-Cu-Li合金 , 时效早期 , 相互作用势

ON SPINODAL BOUNDARIES OF Al-Li ALLOYS

WEI Yinghui , WANG Xiaotian (School of Materials Scince and Engineering , Xi'an Jiaotong University , Xi'an 710049 , China Manuscript received 10 Mareh , 1994)

金属学报(英文版)

The spinodal decomposition can occur in Al-Li alloys containing 5.8-14.2 at.% Li at room temperature. The modutated structure wavelength is approximately 3.1 nm for com mercial Al-LI alloys. The limit composition of the miscibility gap is 3.66 -16.06 at.%Li at 298 K. The highest temperature of the miscibility gap is 377 K.

关键词: : Al-Li alloy , null , null

Li以及Li化合物的添加对17 Mg/12 Al复合材料储氢性能影响的研究?

蓝志强 , 吕韶霞 , 曾科 , 经辉 , 郭进

功能材料 doi:10.3969/j.issn.1001-9731.2016.11.015

通过粉末烧结制备17Mg/12Al复合材料,然后再添加 Li,LiH 以及 LiAlH4混合球磨制备17Mg/12Al＋10M(M＝0,Li,LiH,LiAlH4)复合材料.经研究发现,烧结后的17Mg/12Al 复合储氢材料主要由 Mg17Al12和Mg2 Al3组成,经过20 h机械球磨后,Mg17 Al12和Mg2 Al3转变为具有FCC结构的Mg-Al固溶体.Li以及Li化合物的添加能提高Mg-A l固溶体的储氢容量和改善 Mg-A l 固溶体的热力学性能,如17 Mg/12Al 复合材料的储氢容量为1．73％(质量分数),添加 Li 以及 Li 化合物后,17Mg/12Al＋10M(M＝Li,LiH,LiAlH4)的吸氢量则分别上升到2．23％,2．36％和1．81％(质量分数),且脱氢活化能从194．5 kJ/mol分别降低到172．8,146．3和155．4 kJ/mol.

关键词: 机械合金化 , 固溶体 , 储氢性能 , 激活能