材料期刊网，材料期刊，材料类期刊，材料期刊投稿

Titanium Aluminides: Science, Technology, Applications and Synthesis by Mechanical Alloying

F.H.Froes (Institute for Materials and Advanced Processes (IMAP) , College of Mines and Earth Resources , University of Idaho , Moscow , Idaho 83843-4195 , USA)

材料科学技术（英）

The production. characteristics. and commercialization of monolithic and composite titanium aluminides are summanzed with emphasis on use in the demanding aerospace industry. The attractive elevated temperature properties combined with alow density make these materials of great interest, but inherently low "forgiveness", and environmental concerns, must be overcome before widespread use will occur One synthesis method for the production of monolithic titanium aluminides-mechanical alloying- will be discussed in detail

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Global rare earth resources and scenarios of future rare earth industry

稀土学报(英文版) doi:10.1016/S1002-0721(10)60401-2

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Formation of AlN from Secondary Al Resources

M.Bahgat

材料科学技术（英）

Synthesis of AlN by NH4Cl-assisted direct nitridation of secondary Al resources was studied. Aluminum alloy scrap contained Mg and Zn element was used. Milled Al scrap (-1 mm) was mixed with NH4Cl and heated at 1000℃ for 1 h in presence of 1 L/min N2 flow gas. The nitrided product was evaluated by X-ray diffraction semi-quantitative analysis and scanning electron microscopy (SEM). Aluminium nitride of 90.5% concentration was obtained with a hexagonal crystalline form. AlN is mostly formed in nano-whisker morphology (50~150 nm) which is homogenously distributed.

关键词: AlN , null , null , null

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

Formation of AIN from Secondary Al Resources

材料科学技术（英）

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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）

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

Densification and Sintering Kinetics of Rare Earth (α′+ β′)-Sialon Composites

Hao WANG , T.S.YEN , Hanrui ZHUANG and Weiying SUN (State Key Lab. on High Performance Ceramics and Superfine Microstructure , Shanghai Institute of Ceramics , Chinese Academy of Sciences , Shanghai , 200050 , China)

材料科学技术（英）

The sintering processes of Re-(α' + β')-sialon composites (Re=Sm, Dy, Yb) have been investigated by using a specially designed high temperature dilatometer. The initial densification of various samples starts at about 1200℃, and the maximum shrinkage rate of these sialon composites occurs at about 1500℃. The light rare earth sialon has a noticeably tower densification temperature and a higher final shrinkage. The sirtering kinetics of Re-(α' +β')-sialonare much more complex. The Kingery's liquid phase sintering model appears to be applicable,but the mechanism of mass transport in stage two appears to be changeable. The controlling factor shiffs from solution-precipitation to diffusion when densification process proceeds from the earlier part to the later part of this stage.

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