材料期刊网

CATHODIC PROCESS AND WEAR RESISTANCE OF ELECTRODEPOSITED RE-Ni-W-P-SiC COMPOSITE COATING

Z.C. Guo , X.Y. Zhu , R.D. Xu

金属学报(英文版)

Cathodic deposition current density of the composite coatings increases when SiC par-ticles and rare earth (RE) were added in the bath, which is profitable for Ni- W-P alloyto deposit in the cathod, forming Ni-W-P-SiC and RE-Ni-W-P-SiC composite coat-ings. On the contrary, the addition of PTFE in the bath decreases cathodic depositioncurrent density of the coatings. The current density increases a little when the amountof RE is 7-9g/l; however, the current density increases greatly when the amount ofRE is increased to 11-13g/l. But if the amount of RE is raised further, the currentdensity decreases. Hardness and wear resistance of RE-Ni-W-P-SiC composite coat-ing have been studied, and the results show that the hardness and wear resistance ofRE-Ni-W-P-SiC composite coating increase with increasing heat treatment tempera-ture, which reach peak values at 400℃; while the hardness and wear resistance of thecoating decrease with the rise of heat treated temperature continuously.

关键词: electrodeposition , 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

R & D ACTIVITIES ON AEROSPACE MATERIALS IN KOREA

H.M. Kim(Korea Institute of Machinery and Materials , Korea Manuscript received 26 August 1996)

金属学报(英文版)

This paper briefly reviews research and development programs in Korean aerospace industry,with an emphasis on aircraft materials technology. International collaborations in these areas are outlined and the R & D activities are highlighted against the　background of the national economy.It is shown that the investment from government agencies and large enterprises has led to healthy development of aerospace materials industries in Korea.

关键词: :R & D , null , null , null

R & D OF HYDROGEN ABSORBING ALLOYS IN JAPAN

K. Mii (Sumitomo Metal Industries , Ltd. , 1-t-3 Otemachi , Tokyo 100 , Japan)M Amano (National Research Institute for Metals , 1-2-1 Sengen , Tsukuba 305 , Japan)

金属学报(英文版)

The R & D of hydrogen absorbing alloys in Japan started in the early 1970s.Many alloys such as TiMm1.5 based alloys, Fe-Ti-O alloys (e.g. FeTi1.15 O0.024) andthe(mischmetal)Ni5 based alloys (e.g. MmNi4.5 Cr0.46 Mn0.04) were developed by the early 1980s. The application of these alloys to hydrogen storage, heat storage, heat pump, hydrogen purification and motor vehicles has been tried in many iaboratories,and the various techniques for using hydrogen absorbing alloys have been developed.The standarkization of evaluation methods for hydrogen absorbing alloys has been promoted by the Ministry of International Trade and Industry (MITI), and four of them were established as Japanese Industrial Standard (JIS).Alloys for Ni-Metal Hydride batteries have been extensively investigated since 1987in Japun. Mm-Ni-Co-Al-Mn alloys (e.g. MmNi3.55 Co0.75Al0.9Mn0.4) have been devel-oped and commereialized since 1990. The amount of production of small-size Ni-MH batteries in 1995 was about three hundred milliion in number and about one hundred billion yen. The R & D for higher enerpy-density Ni-MH batteries is intensively in progress.MITI and STA (Science and Technology Agency) have promoted the R & D of hydro-gen absorbing alloys in Japan by carrying out the national projects such as Sunshine Program (MITI: 1974-1993) and Utilization of Wind Engeray (STA 1980-1985). The New Sunshine Program (MITI 1993-2020) have started in 1993. This program con-tains the application of hydrogen absorbing alloys to Economical- Enerpy- City System and to We-NET (International Clean Energy System of Technology Utilizing Hydro-gen: World Energy Network.

关键词: hydrogen absorbing alloy , null , null , null

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

Exceptionally strong magnetism in the 4d perovskites RTcO(3) (R = Ca, Sr, Ba)

Physical Review B

The evolution of the magnetic ordering temperature of the 4d(3) perovskites RTcO(3) (R = Ca, Sr, Ba) and its relation with its electronic and structural properties has been studied by means of hybrid density functional theory and Monte Carlo simulations. When compared to the most widely studied 3d perovskites the large spatial extent of the 4d shells and their relatively strong hybridization with oxygen weaken the tendency to form Jahn-Teller like orbital ordering. This strengthens the superexchange interaction. The resulting insulating G-type antiferromagnetic ground state is characterized by large superexchange coupling constants (26-35 meV) and Neel temperatures (750-1200 K). These monotonically increase as a function of the R ionic radius due to the progressive enhancement of the volume and the associated decrease of the cooperative rotation of the TcO(6) octahedra.

关键词: total-energy calculations;augmented-wave method;basis-set;oxides

ANOMALOUS 3D-ANISOTROPY OF R2FE14C AND R2FE14B COMPOUNDS

Journal of Magnetism and Magnetic Materials

The temperature dependence of the anisotropy field H(A) and the thermal expansion DELTA-l/l0 of R2Fe14X (R = Gd, Lu; X = B,C) were measured by applying the SPD technique for H(A)(T) and a membrane technique for DELTA-l(T)/l0. Comparing Lu2Fe14B and Lu2Fe14C the difference in the temperature dependence of H(A) is associated with the difference in the Invar-like thermal expansion between the two compounds.

关键词: 3d magnetism;anisotropy;gd2fe14b

D301R树脂对水溶液中硝基苯的吸附性质

华英杰 , 王崇太 , 李天略 , 何猛雄 , 徐坤琴

应用化学 doi:10.3724/SP.J.1095.2011.00631

研究了D301R弱碱性阴离子交换树脂对水中硝基苯的吸附作用,测定了不同温度下吸附的动力学曲线和吸附等温线,提出了吸附动力学模型,计算了平衡吸附量、吸附活化能和吸附焓等.实验结果表明,吸附动力学符合表面过程控制的准二级反应模型,其速率常数k2在300 K时为3.74×10-2 g/(mg·min),并随温度的升高而升高；平衡吸附量在300 K时为5.02 mg/g,且随温度的升高而降低；吸附活化能为39.02 kJ/mol;吸附等温线符合Langrnuir吸附模型,吸附焓为-22.47 kJ/mol,吸附作用力主要是氢键.

关键词: D301R树脂 , 硝基苯 , 吸附动力学 , 吸附等温线

INVESTIGATION OF THE INTRINSIC PARAMETER ((B)OVER-BAR(2)(R(0))) FOR 3D(5) IONS IN THE CASE OF CHARGE MISFITTING SUBSTITUTION

Radiation Effects and Defects in Solids

The empirical superposition model has been applied to study the zero-field splitting and its stress; dependence for 3d(5) ions in some crystals. In the calculations, the reasonable local lattice relaxation and local compressibility changes have been taken into account in the case of charge misfitting substitution. The calculated intrinsic parameters (b) over bar(2)(R(0)) show good agreement with the normal (b) over bar(2)(R(0)) which is obtained from the 3d(5) ions in many crystals. So, the disparity between the parameter (b) over bar(2)(R(0)) obtained in the case of isocharge substitution and that in the case of charge misfitting substitution shown in the previous literature can be removed and the superposition model is applicable to the case of charge misfitting substitution.

关键词: superposition model;electron paramagnetic resonance;local lattice;relaxation;local compressibility;mn2+;fe3+;zero-field splittings;superposition-model;spinel crystals;mn2+

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