材料期刊网

SCALING PROPERTIES OF INTERFACES IN CRYSTALS UNDER NONEQUILIBRIUM CONDITIONS

D. W Shi , J. Y Huang and Q. W Long(International Centre for Materials Physics , Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China Laboratory of Atomic Imaging of Solids , Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , ChinaState Key Laboratory for Fatigue and Fracture of Materials , Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China )

金属学报(英文版)

We proposed an equation of Langevin type to describe the interface evolution in crystals under nonequilibrium conditions(such as in Cu-Fe or Cu-Co system upon ball miling). The scaling property (H) of this equation is in good agreement with the Monte Carlo simulations decribed by Bellon and Averback. In this equation the volume dchsion and intedece diffusion are all important and this is consistent with some experimental results.

关键词: scaling , null , null , null

WIDE-BAND LASER CLADDING: WEAR AND CORROSION RESISTANCE OF A Ni-BASED ALLOY

Q. Y Pan , WD. Huang , YM. Li , X. Lin , YH. Zhou and X.C. Yan( State Key Lab. of Solidification Processing , Northwestern Polytechnical University , Xi'an 710072 , China ( Laser Processing Center , Tianjin College of Textile Technology , Tianjin 300160 , China )

金属学报(英文版)

A novel wide-band laser cladding system, with high rate of cladding, has been developed in the present work. The system mainly consisted of a 5kW CO2 laser, an automatic Fowder feeder and a wide-band scanning rotative polygon mirmr which can produce a linear or rectangular focused laser beam. Using this system, a Ni-Cr-Si-B alloy powder was cladded on the sudece of tgpe 321 austenitic stainless steel in onder to improve its wear and cormsion resistance. The pitting cormsion, high temperuture oxidation and wear tests were conducted in onder to evaluate the propertles of the laser cladded layer. The results demonstrated that the cladded layer can significantly improtte the adhesive wear and pitting cormsion resistance of the substmte. Moreover,the cladded layer exhibited good oxidafion resistance, which is almost the same as that of GMR-235D N-based superalloy.

关键词: austenitic stainless steel , null , null , null

ON THE A/D TYPE TWIN BOUNDARY IN 18R MARTENSITE OF A Cu-Zn-Al ALLOY

J.X. Zhang , YF. Zheng , W .Cai and L. C. Zhao (School of Materials Science and Engineering , Harbin Institute of Technology , Harbin 150001 , China Laboratory of Atomic Imaging of Solids , Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China )

金属学报(英文版)

The A/D type twin boundary in a Cu-Zn-Al shape memory alloy appears curved under TEM and shows impularly sermted steps under HREM Crystallogmphic analysis shows that the macroscopic curve results hem non-selfaccommodation of the boundary, the deviation from exact twin orientation and a pwtrential orientation for lower boundary enerpy.

关键词: shape memory alloy , null , null

MECHANICAL PROPERTIES OF A TYPE OF Al-ALLOY WELD

ZH Tu , Z Zhang , L.Z. Zhaoand T.X. Mao (Cryogenic Laboratory , Chinese Academy of Sciences , Beijing 100080 , China) (Institute of Mechanics , Chinese Academy of Sciences , Beijing 100080 , China )

金属学报(英文版)

The mechanical properties of a type of Al-alloy weld including strength, fracture tough-ness and ductility were comprehensively studied at different temperatures. The frac-ture behavior and weld micro features were also characterized. The surface crack test method was adopted to study the fracture toughness and a multiple specimen test ap-paratus was designed to perform the cryogenic experiments. The relationship between the mechanical properties and temperature was obtained together with the fracture toughness distribution in the weld.

关键词: Al-alloy weld , null , null , null

INFLUENCE OF EXTRUSION ON DAMPING CAMCITIES OF AS-SPRAY DEPOSITED HIGH SILICON ALLOY ZA27 MODIFIED BY CERIUM

YC. Liu , G.C. Yang , YL. Lu and Z.G. Zhu (State Key Lab. of Solidification Processing , Northwestern Polytechnic University , Xi'an 710072 , China Laboratory of Internal Friction and Defects in Solids , Chinese Academy of Science , Hefei 230031 , China )

金属学报(英文版)

The effects of cerium modification and extrusion on the resultant damping behavior and mechanical properties of the as-sprayed high silicon alloy ZA27 were investigated in an thort to develop a new functional material possessing high damping capacity and good mechanical properties. The damping capacity, as well as the rslative dynamic modulus, was tneasured at frequencies of 1 and 4 Hertz over the 30 to 200℃runge. At below 80℃ the as-sprayed materials appear to be approximately Asquency independent. Above 80℃, the,naterials becotne temperature sensitive, exhibiting the highest damping for the lowest hequency. The extruded, as-sprayed high silicon alloy ZA27 modified by cerium has the highest damping capacity and elongation values among them. The micro8tructure of the as-sprayed high silicon alloy ZA27 modified by 0. 5 wt% cerium was made up of fine lamellar eutectoid, porositg, a light dot-like phase and a polygonal silicon-rich phase. Finally, the opemtive damping tnechanisms were discussed in light of the data obtained hem characterization of microstructure and damping capacity. The high damping capacity was attributed primarily to phase interface thermoelastic damping between the lamellar phases with various substrvctures,except for the grain refinement.

关键词: spray deposition , null , null , null

Structure, Fluorescence and Stability of CdS Nanoparticles Prepared in Air

Wei CHEN , Zhaojun LIN , Zhanguo WANG , Yan XU and Lanying LIN (Lab. of Semicond. Mater. Sci. , Institute of Semiconductors , Chinese Academy of Sciences , Beijing 100083 , China )

材料科学技术（英）

CdS nanoparticles were prepared in air and their stability by air annealing was studied. A small change in crystal structure and particle size was observed by air annealing, but a rapid reduction in fluorescence was found. Through investigation, it is revealed that it is the surface change or reconstruction rather than the variation of the size or structure that decreases the fluorescence.The emission of the particles consists with two peaks which are dependent on the excitation energy. The two peaks are considered to be arisen from "two" different sizes of nanoparticles and may be explained in terms of selectively excited photoluminescence. Finally we discuss why the discrete state of nanoparticles are able to be resolved in the photoluminescence excitation spectrum, but could not be differentiated in the absorption spectrum.

关键词:

STUDY ON STRUCTURE AND PROPERTIES OF Ni-W-SiC COMPOSITE COATING

K. Y Ma , Z.C. Guo , M.F. Wen , X. W Yang and F. Han ( Kunming University of Science and Technology , Kunming 650093 , China China National Nonferrous Metals Imp. & Exp. Corp. , Shanxi Company , Xi'an 710000 , China )

金属学报(英文版)

The effects of electroplating conditions on the composition of N-W-SiC composite coating were studied; the znfiuence of heat-treatment and nitrocarburization on the microstructure, hardness and wear resistance of the coating were discussed. The results showed that an amorphous composite coating, containing(wt%) 50-55Ni, 42-45.IW and 3.0-7.6SiC, could be electroplated on the matrix. Afier heat-treatment or nitrocarburization the coating crystallized to form some new phases, and the haordness and wear resistance of the composite coating were enhanced retmarkably.

关键词: electroplating , null , null , null

EMISSION M■SSBAUER SPECTROSCOPY OF NiTi SHAPE MEMORY ALLOY

Y G. Li and CS. Xue (Institute of Semiconductor Research , Shandong Normal University , Jinan 250014 , China)G.L. Zhang(Shanghai Institute of Nuclear Research , The Chinese Academy of Sciences , Shanghai 201800 , China )

金属学报(英文版)

The emission Mssbauer Spectroscopy in cotnbination with transmission electron microscope was used to study NiTi shape memory alloy. The damage and the precipitated phase in NiTi alloy have heen discussed.

关键词: emission m■ssbauer spectroscopy , null

Introduction to atmospheric corrosion research in China

Science and Technology of Advanced Materials

In this paper, we introduce the research on atmospheric corrosion in China. We describe the climate characteristics and the classification of atmospheric corrosivity across the whole country. We also describe the rusting evolution under simulated wet/dry cyclic conditions. (C) 2007 NIMS and Elsevier Ltd. All rights reserved.

关键词: atmospheric corrosion;corrosivity;rusting evolution;weathering steels;rust;mechanism;so2;o-3;no2

Recent Advances of Laser Coating Technology in China

LIANG Yong LI Ruiguo Institute of Metal Research , Academia Sinica , Shenyang 110015 , ChinaInstitute of Corrosion and Protection of Metals , Aademia Sinica , Shenyang , 110015 , China

材料科学技术（英）

Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.

关键词: laser , null , null , null , null