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THE FORMABILITY OF COMPLEX FLOURIDE COMPOUNDS

LI Zheng , LIU Honglin , CHENG Zhaonian , CHEN Nianyi , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , ChinaZHOU Jiaju , Institute of Chemical Metallurgy , Academia Sinica , Beijing , China CHEN Nianyi , Professor , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

The formability of complex flourides has been studied by chemical bond parameter-pattern recognition method. In a multi-dimensional space spanned by ionic radius, ionic polarizability, electronegativity and ionic charge of the metal elements, the binary complex flouride-forming systems and binary flouride systems without complex flouride formation distribute in different regions with a clear-cut boundary. The mathematical models obtained are useful for new complex flouride predicton.

关键词: complex flouride , null , null

MECHANISM OF EXTRACTION AND STRIPPING OF Fe(Ⅲ) WITH PRIMARY AMINE N1923 AS EXTRACTANT AND n-OCTANE AS DILUENT

LIU Huizhou , YU Shuqiu , CHEN Jiayong , Institute of Chemical Metallurgy , Academia Sinica , Beijing , China LIU Huizhou , Institute of Chemical Metallurgy , Academia Sinica , Beijing 100080 , China

金属学报(英文版)

Mechanism of extraction of Fe (III) from sulphate solution by primary amine N1923 and stripping of Fe loaded organic phase with dilute H_2SO_4 was investigated. The organic phase was characterized by FT-IR and photon correlation spectroscopy. The composition of extracted species as well as the content of H_2O in organic phase were determined. The dependence of both the rate of extraction and stripping on the formation of reverse micelle in primary amine (N1923)system has been confirmed. It is shown that the extraction of Fe(III) by primary amine sulphate may be related to the adduct formation or cation exchange reaction under different concentrations of H_2SO_4 in aqueous solution.

关键词: Fe(III) , null , null , null

Application of Microwave Radiation to Extractive Metallurgy

LIU Chunpeng XU Yousheng HUA Yixin Kunming Institute of Technology , Kunming , 650093 , China.

材料科学技术(英文)

In applying the microwave radiation to extractive me- tallurgy,it is essential first of all to find the extent of microwave energy absorbed by various minerals experi- mentally.In this paper,more than 25 kinds of common useful minerals have been individually irradiated by a 500 W,2450 MHz microwave source in an enclosed quartz crucible to ascertain their heating temperature in a definite time.In addition,the reduction and cbloridization tests were also carried out on the titanomagnetite concentrate and pentlandite with microwave heating,respectively. These experiments indicate potential applications of util- izing microwave energy in extractive metallurgy.

关键词: microwave radiation , null , null , null

OXIDE METALLURGY-ITS PURPOSES AND PRACTICAL APPROACHES

Z. T. Ma and D. Janke(Institute of Iron and Steel Technology , Freiberg University of Mining and Technology , Germany)

金属学报(英文版)

Useder certain conditions, nonmctallic inclusions such as oxides, sulfides, nitrides and carbides are no longer harmful to sted service properties. With the new concept of oxide metallurgy, these properties can be improved by generating fine oxide inclusions which serve as heterogeneous nuclei for sulfide and fine ferrite[1-4]. A novel continuous casting (CC) process is expected to be created with the utilization of oxide metallurgy. This is also useful for the forthcoming technologies of direct rolling and near-net-shape casting. The main idea of oxide metallurgy consists of an alternative oxidation technology. It is based on steels treated by complex metals such as Ti, Zr, Ti-Zr alloys and rare earth metals. The selected deoxidants should follow the required conditions which are concluded in this paper.

关键词: oxide , null , null , null

Improvement of Ductility of Powder Metallurgy Titanium Alloys by Addition of Rare Earth Element

Yong LIU , Lifang CHEN , Weifeng WEI , Huiping TANG , Bin LIU

材料科学技术(英文)

Ti-4.5Al-6.0Mo-1.5Fe, Ti-6Al-1Mo-1Fe and Ti-6Al-4V alloys were prepared by blended elemental powder metallurgy (PM) process, and the effects of Nd on the microstructures and mechanical properties were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was found out that the addition of Nd increased the density of sintered titanium alloys slightly by a maximum increment of 1% because small amount of liquid phase occurred during sintering. The addition of Nd shows little effect on the improvement of tensile strength, while the elongation is significantly improved. For example, the elongation of Ti-4.5Al-6.0Mo-1.5Fe can be increased from 1% without addition of Nd to 13% at a Nd content of 1.2 wt pct.

关键词: Powder metallurgy titanium alloy , null , null , null

SYNTHESIS OF NANO-ZnO PARTICLES FOR ALUMINUM METALLURGY AS INERT ANODE MATERIAL

A.A.A. Saleh , Y. Fu , X.J. Zhai

金属学报(英文版)

Nano-ZnO particle was produced by evaporating zinc powders in air at air °ow-rate from 0.2 to 0.6m3/h. Nano-ZnO particles was formed by the oxidation of the evapo- rated zinc vapor. X-ray di®raction shows the powders to be ZnO with lattice parame- ters of a=0.3249nm and c=0.5205nm. The particle size is dependent upon the transit time from the source to the collection area. The size of particles was ranged between 81 to 103nm. The average density resulted was 4.865g/cm3. Normal ZnO and nano-ZnO were investigated to use them in aluminum metallurgy as an inert anode material. A certain amount of both oxides were molded subsequently inserted to the molten cryolite-aluminum oxide to investigate the corrosive behavior of both oxides. When the sintering temperature increased up to 1300±C, the weight loss ratio rose to 5.01%{7.33% and up to 7.67%{10.18% for nano-ZnO and normal ZnO, respectively. However, when the samples in the molten cryolite aluminum oxide were put for long time, the corrosive rate was found to be higher. It was found that the corrosive loss weight ratio of nano-ZnO anode was much lower than the normal one made from ordinary-ZnO providing that the nano-ZnO is more possible to be use inert anode material.

关键词: reactive evaporation method , null , null

Preparation of graphene by chemical vapor deposition

新型炭材料

Chemical vapor deposition (CVD) is an effective way for the preparation of graphene with large area and high quality. In this review, the mechanism and characteristics of the four main preparation methods of graphene are briefly introduced, including micromechanical cleavage, chemical exfoliation, SiC epitaxial growth and CVD. The recent advances in the CVD growth of graphene and the related transfer techniques in terms of structure control, quality improvement and large area graphene synthesis were discussed. Other possible methods for the CVD growth of graphene were analyzed including the synthesis and nondestructive transfer of large area single crystalline graphene, graphene nanoribbons and graphene macrostructures.

关键词: Graphene;Preparation;Chemical vapor deposition;Transfer;few-layer graphene;epitaxial graphene;large-area;carbon;films;surfaces;nickel;phase

Efficient growth of high-quality graphene films on Cu foils by ambient pressure chemical vapor deposition

Applied Physics Letters

We developed an ambient pressure chemical vapor deposition (CVD) for rapid growth of high-quality graphene films on Cu foils. The quality and growth rate of graphene films are dramatically increased with decreasing H(2) concentration. Without the presence of H(2), continuous graphene films are obtained with a mean sheet resistance of < 350 Omega/sq and light transmittance of 96.3% at 550 nm. Because of the ambient pressure, rapid growth rate, absence of H(2) and readily available Cu foils, this CVD process enables inexpensive and high-throughput growth of high-quality graphene films. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3512865]

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