材料期刊网，材料期刊，材料类期刊，材料期刊投稿

The silicon pickup of interstitialfree steel (IF steel) from resin bonded MgOSiC refractories is studied via a medium frequency induction furnace. Samples of IF steel were heated in MgOSiC crucibles with mould flux cover at 1 600 ℃ for 180 min. The silicon contents of IF steel samples taken from the molten steel in every 30 min were examined and the refractories after heating were investigated by electron probe microanalysis (EPMA) with energy dispersive spectrometer (EDS). The silicon content of steel rapidly increased in the first 90 min of heating, and then decreased because of the formation of liquid layer on the refractory. Liquid layer separated the liquid steel from the bulk refractory and stopped the pickup of silicon. At the same time, desilication via oxygen through the liquid layer and flux started to reduce the silicon content of the liquid steel.

关键词: MgOSiC refractory;silicon carbide;silicon content;steel

采用NaN3燃烧合成高α相氮化硅粉体

王飞 , 沈卫平 , 葛昌纯

稀有金属材料与工程

采用燃烧合成方法,以NaN3作为固态氮化剂,制备了α相含量高达97%以上的氮化硅粉体.研究了外部氮气压力对于燃烧合成氮化硅粉体的影响.NaN3的加入主要是为燃烧合成反应提供了比N2分子更高化学活性的内部氮源(N3原子团和N原子),同时作为Si-N反应的催化剂,使Si粉在氮气中的燃烧合成反应更加容易进行.适量的NaN3加入能够促进Si粉的完全氮化并提高燃烧产物中的α-Si3N4含量.详细探讨了采用NaN3作为固态氮化剂条件下可能的氮化硅燃烧合成机理.

关键词: 燃烧合成 , NaN3 , 氮化硅

天然海水中NaN3对316L不锈钢表面微生物膜催化阴极氧还原的影响

聂鸳鸳 , 段继周 , 杜敏 , 侯保荣

中国腐蚀与防护学报 doi:10.11902/1005.4537.2013.160

利用荧光显微观察技术选择临界使用浓度的NaN3,分别在O2及N2气氛下采用循环伏安及电化学阻抗技术研究其氧还原过程的电化学行为.结果表明,不锈钢表面的生物膜能够加大还原峰电流密度值,当使用临界浓度的NaN3处理不锈钢试样后,还原峰值明显减小,且峰电位均负移.微生物膜能够促进电子传递给最终电子受体O2,同时降低不锈钢材料发生腐蚀的可能性.由此推测,天然海水中,316L不锈钢表面微生物膜改变了传统阴极氧还原的电子传递途径,即加速了O2作为最终电子受体的电子传递过程,催化了O2的还原;同时,还能够抑制不锈钢材料的腐蚀.

关键词: 天然海水 , 316L不锈钢 , NaN3 , 微生物膜 , 细胞色素c氧化酶 , 氧还原

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

大爆炸核合成相关的8Li(d, p)9Li反应截面测量

李志宏 , 柳卫平 , 白希祥 , 郭冰 , 连钢 , 颜胜权 , 王宝祥 , 陆昀 , 曾晟 , 苏俊

原子核物理评论 doi:10.3969/j.issn.1007-4627.2005.01.006

利用8Li次级束测量了质心系能量7.8 MeV 2H(8Li, 9Li)1H反应的角分布, 导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数.

关键词: 8Li(d,p)9Li反应 , 角分布 , 天体物理S因子 , 渐近归一化系数

CRYSTAL STRUCTURE OF γ-Li_xFe_2O_3 WITH ELECTROCHEMICAL INSERTION OF Li

HUANG Jianshun CHEN Junming Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China Research Associate , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

Crystal structure of γ-Li_xFe_2O_3,inserted Li electrochemically,was studied by Moss- bauer spectroscopy together with X-ray diffraction,XPS and electrochemical method,On the insertion of Li at low current density,the crystal structure is keeping original spinel; while at higher current density or by thermal activation,owing to violent movement of Li~+ ions,part of crystal structure transforms into rock type similar to face-centered cubic structure of ferrous oxide.The transition channels during insertion of Li~+ ions and limitation of Li~+ ions inserted were discussed.

关键词: null , null , null

Al—Li合金的晶界断裂

姚大平 , 张匀 , 胡壮麒 , 李依依

材料研究学报

本文研究了两种晶粒组织的二元Al-Li 合金拉伸性能与断裂行为。结果表明Al-Li 合金力学性能与晶粒尺寸有关,其断裂行为决定于PFZ 内平面滑移或晶界沉淀相与滑移的交互作用。

关键词: Al—Li合金 , intergranular fracture , planar slip

Effect of Li(3)N additive on the hydrogen storage properties of Li-Mg-N-H system

Journal of Materials Research

The effect of Li(3)N additive on the Li-Mg-N-H system was examined with respect to the reversible dehydrogenation performance. Screening Study with varying Li(3)N additions (5, 10, 20, and 30 mol%) demonstrates that all are effective for improving the hydrogen desorption capacity. Optimally, incorporation of 10 mol% Li(3)N improves the practical capacity from 3.9 wt% to approximately 4.7 wt% hydrogen at 200 degrees C, which drives the dehydrogenation reaction toward completion. Moreover, the capacity enhancement persists well over 10 de-/rehydrogenation cycles. Systematic x-ray diffraction examinations indicate that Li(3)N additive transforms into LiNH(2) and LiH phases and remains during hydrogen cycling. Combined structure/property investigations suggest that the LiNH(2) "seeding" should be responsible for the capacity enhancement, which reduces the kinetic barrier associated with the nucleation of intermediate LiNH(2). In addition, the concurrent incorporation of LiH is effective for mitigating the ammonia release.

关键词: complex hydrides;improvement;mixtures;imides;amide;h-2

SUPERPLASTICITY OF A RAPIDLY SOLIDIFIED AI-Li ALLOY

MANG Weishi WANG Guozhi ZHANG Yongchang HU Zhuangqi SHI Changxu Institute of Metal Research , Academia Sinica , Shenyang , China Yongchang Associate Professor , Institute of Metal Research , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

A rapidly solidified microcrystalline Al-Li-Cu-Mg-Zr alloy and its superplasicity have been investigated.An optimum tensile elongation of 585% was obtained at 540℃ and strain rate 1.67×10~(-2)s~(-1).The superplastic Al-Li alloy is manufaetured using thermomechanical pro- cessing:solution,overaging,warm rolling and recrystallization.Microstructural changes in thermomechanical processing and cavitation occurred during superplastic deformation have been observed.The superplastic failure of alloy may be caused mainly by nucleation and growth of cavities as well as the linkage around grains.

关键词: superplasticity , null , null , null