材料期刊网

EFFECT OF REINFORCEMENT VOLUME FRACTION ON PRECIPITATION IN MATRIX OF SiC_p/AI COMPOSITE

LIN Junshan , LI Pengxing , WU Renjie Shanghai Jiao Tong University , Shanghai , China postdoctoral , Institute of Composite Materials , Shanghai Jiaotong University , Shanghai 200030 , China

金属学报(英文版)

The differential scanning calorimetric(DSC) and transmission electron microanalysis (TEM) techniques were used to study the kinetic process of precipitation in matrix of cast SiC_p/2024 composites.The results showed that precipitation reactions of GP zone and intermediate phase S'(Al_2CuMg)in the composites were accelerated compared with SiC-free material,the peak temperatures of both reactions were decreased.The reaction enthalpies of both the GP zone and intermediate phase S' formation in the matrix were substantially decreased after the addition of SiC.TEM analysis found that the alloying element Mg segregated at the SiC/Al interfaces,and was depleted in the matrix near the interface.The precipitation-free zones(PFZ) and precipitation-sparse zones(PSZ) formed near the interfaces,as a results,the volume fraction of precipitates in matrix was reduced.

关键词: SiC_p/2024 composite , null , null

EFFECTS OF STRESS RATIO AND FREQUENCY ON CORROSION FATIGUE CRACK GROWTH MECHANISM IN LOW ALLOY STEELS

HAN Enhou HAN KYumei ZHENG Yuli KE Wei Corrosion Science Laboratory , Institute of Corrosion and Protection of Metals , Academia Sinica , Shenyang , China postdoctoral , Institute of Corrosion and Protection of Metals , Academia Sinica , Shenyang 110015 , China

金属学报(英文版)

Based on theoretical analysis about local strain,strain rate and dissolving rate at crack tip, the corrosion fatigue crack growth rate of steels ZG20SiMn and SM50B-Zc in fresh water and 3.5% NaCl solution were measured experimentally,and the PH and electrode potential within crack were also measured continuously along with crack propagating.It showed that the increase of crack growth rate,caused by both decreasing frequency and raising stress ratio,was mainly accelerated by hydrogen embrittlement.

关键词: corrosion fatigue , null , null , null , null , 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:

Development of rapidly quenched soft magnetic materials in China

Shaoxiong ZHOU

材料科学技术（英文）

The discovery of the first Fe-based ferromagnetic amorphous alloy in 1966 had made an impact on conventional magnetic materials because of its unique properties. Since then, a number of amorphous magnetic materials have been successfully developed and used in a wide variety of applications. A brief review of R & D activities on amorphous soft magnetic materials in China is given from the beginning to the present in a somewhat chronological order, followed by a brief introduction to their applications on electric and electronic industries. An analysis and a prospect of Chinese market of such amorphous materials are also presented.

关键词:

Recent developments in high temperature intermetallics research in China

Intermetallics

A comprehensive survey was made of various advances of intermetallics research in China. The investigation focussed on the fundamental research and materials development. Charge density distribution and site occupancy of alloying elements, environmental embrittlement and chemical reaction, interface structures and phase transformation at the atomic scale, nanocrystalline intermetallics and its thermal stability, superplastic behavior and anomalous yield strength peak are reviewed. Several Ti-Al and Ni-Al based alloys have been manufactured, and show good mechanical properties. Diverse components have been fabricated successfully. (C) 2000 Elsevier Science Ltd. All rights reserved.

关键词: aluminides, miscellaneous;hydrogen embrittlement;mechanical properties;at high temperatures;superplastic behavior;phase interfaces;grain-boundary fracture;in-situ composites;environmental;embrittlement;hydrogen embrittlement;ni3al;compression;alloys;co3ti;boron;feal

Key R&D activities for development of new types of wrought magnesium alloys in China

Transactions of Nonferrous Metals Society of China

Many researchers in China are actively engaged in the development of new types of wrought magnesium alloys with low cost or with high-performances and novel plastic processing technologies. The research activities are funded primarily through four government-supported programs: the Key Technologies R&D Program of China, the National Basic Research Program of China, the National High-tech R&D Program of China, and the National Natural Science Foundation of China. The key R&D activities for the development of new wrought magnesium alloys in China are reviewed, and typical properties of some new alloys are summarized. More attentions are paid to high-strength wrought magnesium alloys and high-plasticity wrought magnesium alloys. Some novel plastic processing technologies, emerging in recent years, which aim to control deformation texture and to improve plasticity and formability especially at room temperature, are also introduced.

关键词: wrought magnesium alloy;microstructure;properties;alloy designing;plastic deformation;research projects;y-zr alloys;mechanical-properties;mg-4y-4sm-0.5zr alloy;grain-refinement;rare-earth;microstructure;gd;phase;temperature;evolution