材料期刊网

A New Approach to Isothermal Precipitation Kinetics of Carbides

Wantang FU , Zheng WANG , Tianfu JING and Yangzeng ZHENG (Dept. of Materials Engineering , Yanshan University , Qinhuangdao 066004 , China)Jianguo MA(Harbin Frame Factory of Electrical Cable , Harbin , China)

材料科学技术（英文）

A new approach to isothermal precipitation kinetics of carbides in undercooled austenite has been proposed firstly, which is based on measuring the changes of Ms point vs holding time at a certain temperature. The isothermal precipitation kinetics (PTT) Curve of carbides was obtained by the use of the method for 13Cr-8Mn-0.07N stainless steel, and compared with the results of chemical phase analysis and TEM method. The results show that the new method is more sensitive and convenient than the other methods.

关键词:

Capacitance of High-Voltage Coaxial Cable in Plasma Immersion Ion Implantation

X.B. Tian , L.P. Wang , D. T.K.Kwok , B. Y Tang , P.K.Chu

材料科学技术（英文）

Plasma immersion ion implantation (PIII) is an excellent technique for the surf see modification of complex-shaped components. Owing to pulsed operation mode of the high voltage and large slew rate, the capacitance on the high-voltage coaxial cable can be detrimental to the process and cannot be ignored. In fact, a significant portion of the rise-time/fall-time of the implantation voltage pulse and big initial current can be attributed to the coaxial cable.

关键词:

PRECIPITATION BEHAVIOR IN A Cu—Sn—Ni—Zn—P LEAD FRAME MATERIAL

W.H.Tian , C.K.Yan , M.Nemoto

金属学报(英文版)

Transmission electron microscopy(TEM) observations were carried out for examining the precipitation behavior in a Cu-Sn-Zn-P lead frame material.TEM observations revealed that the precipitate is hexagonal Ni5P2 and the orientation relationship between the Cu matrix and Ni5P2 precipitate is (111)fcc//(0001)hcp,[101]fcc//[1120]hcp,where the suffix fcc denotes the Cu matrix and hcp denotes the hexagonal Ni5P2 precipitate.The Ni5P2 precipitate is ovoidal in shape at the beginning of aging at lower temperature.By prolonging the aging time or increasing the aging temperature,Ni5P2 precipitate grows and shows a rod-like shape.The Ni added Cu based lead frame material has a comparative mechanical properties with that of TAMAC15 which has been developed and used in electrical industry.

关键词: lead frame materials , null , null

Mechanism of competitive growth during directional solidification of a nickel-base superalloy in a three-dimensional reference frame

Acta Materialia

The microstructure evolution of bicrystal samples during directional solidification was studied, both by simulation and experiment, to explore the mechanism of competitive growth. A new orientation relationship of bicrystal samples, the non-uniplanar case, is proposed, which expands the orientation relationship of bicrystal samples from two dimensions to three dimensions. The results show that, in the non-uniplanar case, the favorably oriented grain overgrows the unfavorably oriented grain by developing new dendrites in the lateral gap where the primary dendrites of the unfavorably oriented grain diverge from the mold wall. During this process, the grain boundary is found to move in two directions, one perpendicular to the grain boundary and the other parallel to the grain boundary. To characterize the state of dendrite growth, a three-dimensional reference frame is constructed. In this reference frame, the mechanism of competitive growth can be categorized as a converging case, a non-uniplanar case and a diverging case. Furthermore, the simulation results are in good agreement with the experimental findings. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

关键词: Directional solidification;Competitive growth;Non-uniplanar case;3-D;reference frame;Rotation;single-crystal superalloys;low-angle boundaries;seed melt-back;grain;structures;prediction;orientation;castings;model

Emei Semiconductor Material Factory

LI Bencheng Emei Semiconductor Material Factory.Emei , 614200 , China.

材料科学技术（英文）

关键词:

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（英文）

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

Development of Cast Superalloys for Gas Turbines in China

CHEN Rongzhang CHEN Wanhua Institute of Aeronautic Materials , Beijing 100095 , China.

材料科学技术（英文）

As in other countries,significant achievements in the research of cast superalloys for many years have also been obtained in China.These results are important contribu- tion to the development of aero and land-based gas tur- bine engines.

关键词: cast superalloy , null

R&D STATUS ON INTERMETALLICS IN CHINA

CHEN Guoliang(State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 , China)SHI Changxu (Academia Sinica , Beijing 100864 , China)

金属学报(英文版)

This paper briefiy introduces the R&D of intermetallics in China. R&D on intermetallics in a national scale in China began near ten years ago. The investigation in past years focused on the fundamental research and materials development. A significant progress has been made. Various components that made of Ti3Al Ni3Al, TiAl and Fe3Al have been successfully manufactured Some of them have been evaluted. It is expected that some intermetallic alloys will be produced in an industrial scale in the near future.

关键词: :intermetallic alloys , null , null , null

Further development of NdFeB magnet industry in China

Yang LUO

材料科学技术（英文）

Due to continued growth in key markets, a broadening of application base and performance improvements, the market demands of NdFeB magnet increased steadily in 1998, and the global output of sintered NdFeB magnet exceeded 10,000 t, in spite of the economic recession in Asia. In 1998 China produced 3,850 t sintered NdFeB block magnet, with an annual growth rate of +22% over the output in 1997.

关键词: