检索结果-南通市图书馆

Effect of rapid quenching on the microstructure and electrochemical characteristics of La_(0.6)Ce_(0.4)Ni_(3.6)Co_(0.65)Mn_(0.4)Al_(0.2)Ti_(0.05_(FeB)_(0.1) hydrogen storage alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2010年第6期29卷 593-596页

作者： ZHANG Peilong SONG Xiping WANG Xiuli PEI Pei LUO Guiping TU Jiangping CHEN Guoliang State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 000China Whole Win(Beijing) Materials Sci.& Tech.Co. Ltd.Beijing 100083China Department of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China

In order to improve the cycling stability of AB5 type alloy electrodes,rapid quenching technology and new alloy composition design were employed.A hydrogen storage alloy with nominal composition La0.6Ce0.4Ni3.6Co0.65Mn0.4Al0.2Ti0.05（FeB）0.1 was prepared by vacuum magnetic levitation melting under high purity argon atmosphere,followed by rapid quenching at different cooling rates.XRD results show that all alloys exhibit the single-phase CaCu5-type structure.Electrochemical tests indicate that rapid quenching can slightly improve the cycling life of the alloy.Nevertheless,the high-rate dischargeability of the quenched alloys is lower than that of the as-cast alloy.

关键词： hydrogen storage alloys electrochemical properties rapid quenching microstructure

Cycle Stabilities of La_(0.7)Mg_(0.3)Ni_(2.55-x)Co_(0.45)M_x (M=Fe, Cu, Al;x=0, 0.1) Electrode Alloys Prepared by Casting and rapid quenching

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2007年第S1期25卷 419-425页

作者：张羊换赵栋梁董小平郭世海祁焱王新林 Department of Functional Material Research Central Iron and Steel Research Institute School of Materials University of Science and Technology Beijing

La-Mg-Ni system (PuNi3-type) hydrogen storage alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Fe, Cu, Al; x=0, 0.1) were prepared by casting and rapid quenching. Aiming to improve the cycle stabilities of the alloys, Ni in the alloy was partly substituted by Fe, Cu and Al. The effects of the substitution of Fe, Cu and Al for Ni and the rapid quenching on the microstructures and electrochemical properties of the alloys were investigated in detail. The results obtained by XRD, SEM and TEM indicate that the element substitution has no influence on the phase compositions of the alloys, but it changes the phase abundances of the alloys. Particularly, the substitution of Al and Cu obviously increases the amount of the LaNi2 phase. The substitution of Al and Fe leads to a great refinement of the as-quenched alloy′s grains. The substitution of Al strongly restrains the formation of the amorphous in the as-quenched alloy, but the substitution of Fe and Cu is quite helpful for the formation of an amorphous phase. The effects of the substitution of Fe, Cu and Al on the cycle stabilities of the as-cast and quenched alloys are different. The positive impact of the substitution elements on the cycle stabilities of the as-cast alloys is ranked in proper order Al>Fe>Cu, and for as-quenched alloys, the order is Fe>Al>Cu. rapid quenching engenders an unconscious influence on the phase composition, but it markedly enhances the cycle stabilities of the alloys.

关键词： La-Mg-Ni system electrode alloy element substitution rapid quenching microstructures cycle stability rare earths

Relations between quenching Rate and Electrochemical Characteristics of Mm (NiCoMnA1) 5Bx (x=0

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2004年第Z1期22卷 235-241页

作者： Zhang Yanghuan Dept. of Functional Mat. Res. Central Iron and Steel Res. Inst. Beijing 100081 China Sch. of Mat. Inner Mongolia Univ. of Sci. Baotou 014010 China

Low-Co AB5-type Mm(NiCoMnAl)5Bx(x=0, 0.1, 0.2) electrode alloys were prepared by casting and rapid quenching. The effects of the rapid quenching on the lattice constants, microstructures and electrochemical characteristics of the alloys were investigated in detail. The obtained results show that the rapid quenching made lattice constants and cell volume increased. In a range of the quenching rate, rapid quenching can increase the discharge capacities of the alloys. However, the discharge capacity of the as-quenched alloy is lower than that of the as-cast alloy when quenching rate is more than a critical value. The cycle lives of the alloys increase monotonously with the increase of the quenching rate.

关键词： AB5-type electrode alloy Electrochemical characteristics Low-Co Microstructure rapid quenching

Magnetic properties optimization of nanocomposite Nd_9Fe_(85)B_6 magnets by controlling microstructure of as-quenched ribbons

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2014年第3期33卷 299-303页

作者： Yu-Chao Liu Hong-Wei Li Kuo-She Li Dun-Bo Yu Jin-Ling Jin Yang Luo Liang Sun Ning-Tao Quan National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals

To optimize the magnetic properties of nanocomposite Nd9Fe85B6 magnets, the as-quenched ribbons with different microstructures were prepared at six wheel velocities from 10 to 30 m s^-1through rapid quenching,followed by a series of annealing treatments at 550-800 °C for 5-10 min. It is found that both the large initial grains at low cooling rate and high content of amorphous phase at high cooling rate cause a-Fe grains coarsening, which leads to a decline in the strength of exchange coupling interaction and the deterioration of magnetic properties. In order to optimize the magnetic properties, the as-quenched ribbons should be chosen with relatively small initial grains as well as a small amount of amorphous phase. For nanocomposite Nd9Fe85B6 materials, the optimized magnetic properties of Hcj= 446 kA m^-1, Br= 0.86 T,（BH）max=80 kJ m^-3are obtained for ribbons prepared at 18 m s-1after annealing at 620 °C for 5 min.

关键词： Nanocomposite rapid quenching Microstructure Grain sizes

Gaseous and Electrochemical Hydrogen Storage Kinetics of As-quenched Nanocrystalline and Amorphous Mg_2Ni-type Alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2013年第3期28卷 604-611页

作者：张羊换 YANG Tai SHANG Hongwei ZHANG Guofang CAI Ying ZHAO Dongliang Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources Inner Mongolia University of Science and Technology Department of Functional Material Research Central Iron and Steel Research Institute

The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox （x = 0, 0.1, 0.2, 0.3, 0.4） alloys were synthesized by melt quenching technology. The structures of the as-cast and quenched alloys were characterized by XRD, SEM and HRTEM. The gaseous hydrogen storage kinetics of the alloys was measured using an automatically controlled Sieverts apparatus. The alloy electrodes were charged and discharged with a constant current density in order to investigate the electrochemical hydrogen storage kinetics of the alloys. The results demonstrate that the substitution of Co for Ni results in the formation of secondary phases MgCo2 and Mg instead of altering the major phase Mg2Ni. No amorphous phase is detected in the as-quenched Co- ffee alloy, however, a certain amount of amorphous phase is clearly found in the as-quenched alloys substituted by Co. Furthermore, both the rapid quenching and the Co substitution significantly improve the gaseous and electrochemical hydrogen storage kinetics of the alloys, for which the notable increase of the hydrogen diffusion coefficient （D） along with the limiting current density （IL） and the obvious decline of the electrochemical impedance generated by both the Co substitution and the rapid quenching are basically responsible.

关键词： Mg2Ni-type alloy rapid quenching substituting Ni with Co hydrogen storage kinetics

Development of rapidly Quenched Soft Magnetic Materials in China

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research(International) 1999年第2期6卷 44-50页

作者： Zhou Shaoxiong Central Iron & Steel Research Institute

Thediscovery ofthefirstFe-based ferrom agneticam orphousalloy in 1966 had m ade an im pacton conventionalm agnetic m aterialsbecause ofitsuniqueproperties. Since then, a num berof am orphousm agneticm aterialshavebeen successfully developed and used in aw ide variety ofapplica- tions. Abriefreview ofR& Dactivitieson am orphoussoftm agneticm aterialsin Chinaisgiven from the beginning to the presentin a som ew hatchronologicalorder, followed by a briefintroduction to their applicationson electric and electronicindustries. An analysis and aprospectofChinesem arket ofsuch am orphous m aterials are also presented.

关键词： m agneticm aterials am orphousalloy rapid quenching

Fabrication and Properties of rapidly Quenched Fe-6.5wt.%Si Alloy Ribbons

在线全文

学校读者我要写书评

暂无评论

Fabrication and Properties of Rapidly Quenched Fe-6.5wt.%Si ...