材料期刊网

Isothermal Aging Kinetics in CuZnAl Shape Memory Alloy

Zengqi ZHAO Lab.of Physics , Baotou Research Institute of Rare Earth , Baotou , 014010 , ChinaFeixia CHEN Dazhi YANG Dept.of Mater.Eng. , Dalian University of Technology , Dalian , 116024 , ChinaEr BAO Dept.of Mater.Eng. , Yanshan University , Qinhuangdao , 066004 , China

材料科学技术（英文）

Isothermal aging behaviours of a CuZnAl shape memory alloy have been investigated by means of dilatometry.The length of the specimens during isothermal aging from 190 to 280℃ increases with the aging time at each temperature.The isothermal aging kinetics fits in Avrami equation and the time exponent n decreases with the increase in aging temperature.The apparent activation energy for the isothermal aging process was measured to be 109.0kJ/mol,which is about equal to that of a relaxation internal friction peak at about 200℃ (f≈1 Hz) in the alloy.

关键词: isothermal aging kinetics , null , null , null , null

BEHAVIOUR OF α-NITROSO-β-NAPHTHOL IN HEMATITE FLOTATION

WANG Wenmei Baotou Research Institute of Rare Earth , Ministry of Metallurgy Industry , Baotou , ChinaYU Yongfu CHEN Quanyuan Changsha Institute of Mining and Metallurgy , Ministry of Metallurgy Industry , Changsha , China engineer , Baotou Research Institute of Rare Earth , Ministry of Metallurgical Industry , Baotou 014010 , China

金属学报(英文版)

Based on theoretical calculation of electronegativity of groups of flotation reagent and method of infrared adsorption spectroscopy,the collection and adsorption of α-nitroso-β- naphthol in hematite flotation have been studied.The chemical adsorption seems to be predominant owing to formation of pentacyclic nitrosyl chelate compound by atoms of nitrosyl bond in α-nitroso-β-naphthol together with Fe(Ⅲ)on hematite surface.Mean- while,the nonuniform multilayer physical adsorption is also occurred.

关键词: α-nitroso-β-naphthol , null , null , null , null

Relationship between Relaxation Internal Friction Peak at about 200℃(f≈1Hz)and Bainitic Transformation In a CuZnAl Alloy

ZHAO Zengqi CHEN Feixia YANG Dazhi BAO Er ** Physical Laboratory , Baotou Research Institute of Rare Earth , Baotou , 014010 , China*** Dept.of Materials Engineering , Dalian University of Technology , Dalian , 116024 , China**** Dept.of Materials Engineering , Yanshan Uni

材料科学技术（英文）

The present investigation showed that the re- laxation peak at about 200℃ (f≈1Hz) was related to bainitic transformation in a CuZnAl alloy.The peak decreased when bainite precipitated.The activation energy of the peak was the same as the apparent activation energy of bainitic transforma- tion.According to the relations between the peak and the bainitic transformation,the mechanism of the peak has been discussed.

关键词: internal friction , null , null , null

AN APPROXIMATE ANALYTICAL PROCEDURE FOR TERNARY GIBBS-DUHEM EQUATION

WANG Jixin Baotou Research Institute of Rare Earth , Ministry of Metallurgical Industry , Baotou , China Senior Engineer , Baotou Research Institute of Rare Earth , P.O.Box 131 , Baotou 014010 , China

金属学报(英文版)

In the light of estimation model for ternary excess properties,an approximate analytical procedure for ternary Gibbs-Duhem equation was proposed,and verification by previous ternary systems as Cd-Bi-Pb and Zn-In-Cd was also made.

关键词: Gibbs-Duhem equation , null

Recovery of iron from Baotou rare earth tailings by magnetizing roast

稀有金属（英文版） doi:10.1007/s12598-013-0158-2

关键词:

Metastable phases in rare-earth permanent-magnet materials

Journal of Physics D-Applied Physics

A comprehensive review is given of recent advances in the study of metastable phases in rare-earth permanent magnets. The relations between the structures of the metastable and equilibrium phases and the transformations from the former to the latter are discussed. The formation of the phases is found to depend on the difference between the symmetries of the metastable and equilibrium phases. The magnetic properties of the metastable-phase rare-earth permanent magnets synthesized by various processes, such as mechanical alloying, mechanical milling, rapid quenching, hydrogenation, disproportionation, desorption and recombination, solid-state reaction, solid-gas reaction, self-flux and sputtering, are compared. The main conclusion of this article is that searching for new metastable phases with high magnetic performance will be one of the most active directions in the research on rare-earth permanent magnets.

关键词: fe-c alloys;disproportionation-desorption-recombination;solidified;sm-fe;r = nd;high-coercivity;magnetocrystalline anisotropy;intermetallic compounds;remanence enhancement;crystal-structure;high-performance

EFFECT OF RARE EARTH ON VANADIZATION PROCESS IN BORAX BATH

X.K. Tao , X.Cong , R.S. Peng , J.Liu and Z.Y. Liu Tianjin Institute of Technology , Tianjin 300191 , China

金属学报(英文版)

This paper investigates the effect of rare earth elements on the kinetic process, microstructure and mechanical properties of vanadization in borax bath. The results show that addition of rare earth elements to vanadizing agent has obvious catalytic effect on the rate of vanadization, which has been enchanced by 30%. The wear and corrosion resistance of vanadium carbide layer were prompted by the addition of rare earth to the agent. Through increasing vanadium potential of the agent, activating the surface of workpieces and decreasing the activation energy of diffusion of carbon, rare earth elements accelerate the rate of vanadization process.

关键词: rare earth elements , null , null

SYNTHESIS AND IDENTIFICATION OF CONDUCTING POLYANILINE DOPED WITH RARE EARTH CHLORIDE

C.M. Yang , Q.R. Zhang and Z. Fang(Department of Chemistry , Central South University of TecHnology , Changsha 410083 , China)

金属学报(英文版)

Polyaniline doped with rare earth chloride was synthcsized in organic solvent and identified by clemental analysis and ithered spectroscopy. The experimental results show that there exist both doping and complexation at the same time in the resulting product. When pH<4, prototnic acid doping is predominating, whereas rare earth ion complexation is predominating when pH>1. Moreover, polyanitine doped wih rare earth chloride exhibits better thermal stability than that doped with hydrochloric acid.

关键词: dope , null , null , null

Action of New Rare Earth Additions in Cemented Carbide

Chenguang LIN General Research Institute for Non-ferrous Metals , Beijing , 100088 , China

材料科学技术（英文）

The existence form and distribution of new rare earth additions in WC-Co,WC-TiC-Co.Cemented carbide and its actions of purification,modificaiton,solid solution strengthening and restraining phase transformation have been investigated.The results have been used to elucidate property im- provement of the alloys.

关键词: cemented carbide , null , null

Enhanced electron correlation in rare-earth doped Ca(3)Co(4)O(9)

Applied Physics Letters

Thermoelectric and thermodynamic properties of a series of Ca-site rare-earth R(3+) doped Ca(3)Co(4)O(9) were investigated. For a fixed doping level, with the reduction in R(3+) radius, thermopower is found to gradually increase despite the carrier concentration remains unchanged. The scaling behavior between thermopower and electron specific heat coefficient reveals that the additional increase in thermopower originates from enhanced electron correlation which may be attributed to doping-induced chemical pressure. (C) 2010 American Institute of Physics. [doi:10.1063/1.3479923]

关键词: calcium compounds;carrier density;doping profiles;electron;correlations;rare earth metals;specific heat;thermoelectric power;misfit-layered cobaltite;thermoelectric properties;system;substitution;transition;transport;ceramics