材料期刊网

FACTORS AFFECTING SILICA CONTENT OF ALUMINIUM HYDROXIDE PRODUCT IN CARBONIZATION PROCESS

LIU Miaoxiu CHENG Zhaonian CHEN Nianyi Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , ChinaKE Jiajun 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 regularity of the carbonization process in alumina production has been summarized by the pattern recognition and regression.A mathematical model has been proposed to describe the factors affecting the silica content of aluminium hydroxide product.The high concentration of aluminate ions in solution will produce aluminium hydroxide with low content of SiO_2 under the condition of Al_2O_3/SiO_2 ratio kept unchanged.This was confirmed by certain scale experiments.

关键词: carbonization , null , null , null

AN EXPERT SYSTEM FOR COMPUTER AIDED ALLOY STEEL DESIGN—ASPRES

CHEN Yu , CHEN Nianyi Shanghai institute of Metallurgy , Academia Sinica , Shanghai , China PENG Ping , KONG Bingyu Iron and Steel Research Institute , Shanghai Baoshan Iron and Steel Complex , Shanghai , China professor , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

An alloy steel pattern recognition expert system,ASPRES,has been established for the purpose of computer aided optimal design of alloy steel in compositions and process pa- rameters,Pattern recognition techniques are used to abstract inner relationship between mechanical properties and process variables.The ASPRES uses 2-dimensional graph as visual knowledge to represent domain expertise of specific object.Forward and back- ward chaining can be utilized by researcher in predicting sample performances or giving helpful suggestions about the chemical compositions and process parameters according to desired properties.

关键词: pattern recognition , null , null

ELECTRONIC STRUCTURE OF Pd-Y-Si GLASSES

LUO Meiqing CHEN Nianyi Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , ChinaYU Zhizhong Shanghai Institute of Testing Technics , Shanghai , ChianNING Yuantao ZHOU Xinming Kunming Institute of Precious Metals , Kunming , China CHEN Nianyi , Professor , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

The electronic structure of Pd-Y-Si glass has been investigated by ESCA and quantum chem- ical calculation.It was found that the valence electrons of Y transferred to Si atoms in this metallic glass,forming polar covalent bonds.Perhaps these strong covalent bonds link Si and Y atoms to form clusters that hinder the process of crystallization.

关键词: Pd-Y-Si glass , null , null , null

RANGE PARAMETERS IN METALS AND ALLOYS

WANG Dening , WANG Weiyuan Ion Implantation Lab. , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China Associate Professor , Laboratory No.6 , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

The formulae for calculating the electronic stopping power.for heavy ion implanting into metal are derived by using Wigner-Sietz radius r_s,equivalent charge,Fermi velocity and Ziegler's values of hydrogen electronic stopping power.Meanwhile the.formulae of electronic stopping power S_e(E)for alloys with boride or CsCl structure are also proposed.The calculated results are found as follows:these formulae are suitable only for mono-or bi-borides,but not for borides with more complex structure such as Cr_5B_3 or W_2B_5;the coefficient γ,of S_e(E)for al- loys with CsCI structure deviating from Bragg's S_e(E)is directly proportional to charge trans- fer in alloy.This means the larger the charge transfer is,the more stronger the metallic bond is.Hence the S_e(E)created by metallic bond in alloys will increase; there is a tendency for it to increase with increasing separation of two components in alloy on either side of Cr group at same periods,when the two components are in different periods,the tendency is more larger.

关键词: metal , null , null , null

RAMAN SPECTRA OF SODIUM ALUMINATE SOLUTIONS WITH HIGH-CAUSTIC RATIO AND HIGH CONCENTRATION

LIU Miaoxiu CAO Yilin CHEN Nianyi Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , ChinaZHUANG Zhicheng Shanghai Jiaotong University , Shanghai , China Professor , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

The constitution of high-caustic ratio and highly concentrated sodium aluminate solutions has been investigated by Raman spectra method.By comparison with the Raman spectra of crystalline solids of Ca_3[Al(OH)_6]_2 and Ba_2[Al_2(OH)_(10)],it can be concluded that AI(OH)_6~(3-)ion and perhaps its polymers may be formed in these solutions.

关键词: high caustic ratio , null , null

MOLECULAR DYNAMICS STUDY OF STRUCTURE IN MOLTEN SALT SOLUTION NaF-CaF_2

CHENC Zhaonian JIA Zhengming CHEN Nianyi Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China associate professor , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

The NaF-CaF_2 system has been studied by molecular dynamics simulation.The pair correlation functions between cations and anions and the bond angle distributions of cation and anion triplets have been obtained.The bridging and complexing in the system are discussed based on the pair correlation functions and bond angle distributions.The results simulated show that the F~- ions around a Ca~(2+)ion do not form tetrahedron coordination,so some of small complexing clusters such as CaF_4~(2-)are hardly found.A possible structure of F~- ions around Ca~(2+)ions is that three Ca~(2+)ions constitute an equilateral triangle through three Ca-F-Ca bridges and two F~- ions are located over and under the center of the right triangle,respectively.Meanwhile,on the outside of the triangle,every Ca~(2+)ion has other two F~- ions as its neighbors.

关键词: NaF-CaF_2 system , null , null

SOLUBILITY CHARACTERISTICS OF GaAs IN Bi AND THEIR PHASE DIAGRAM

FENG Shuifu ZHO U Jicheng Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China ZHOU Jicheng , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

A modified liquid phase epitaxy apparatus for semiconductor materials was used to measure the solubility of GaAs in Bi.Two phase diagrams rich in Bi under H_2 and N_2 atmospheres were obtained according to the results of measurement.A new phenomenon,in which the parameter Q value(quantity of GaAs dissolved in Bi in fixed time/saturation quantitu,of GaAs in Bi)was different from each other at various temperatures and there existed a maxi- mum Q value at definite temperature,was observed.This phenomenon may be regarded as a common feature of a simple binary metallic system which has the phase diagram similar to that of Bi-GaAs.The difference observed from the dependence of Q values on temperature in both H_2 and N_2 atmospheres was discussed.

关键词: solubility , null , null

CRYSTAL STRUCTURE OF γ-Li_xFe_2O_3 WITH ELECTROCHEMICAL INSERTION OF Li

HUANG Jianshun CHEN Junming Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China Research Associate , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

Crystal structure of γ-Li_xFe_2O_3,inserted Li electrochemically,was studied by Moss- bauer spectroscopy together with X-ray diffraction,XPS and electrochemical method,On the insertion of Li at low current density,the crystal structure is keeping original spinel; while at higher current density or by thermal activation,owing to violent movement of Li~+ ions,part of crystal structure transforms into rock type similar to face-centered cubic structure of ferrous oxide.The transition channels during insertion of Li~+ ions and limitation of Li~+ ions inserted were discussed.

关键词: null , null , null

ROUGHNESS-INDUCED SHEAR RESISTANCE OF MODE Ⅱ CRACK GROWTH

ZHENG Yesha WANG Zhongguang AI Suhua State Key Laboratory of Fatigue and Fracture for Materials , Institute of Metal Research , Academia Sinica , Shenyang , China postdoctor , Shanghai Institute of Ceramics , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

It is obtained in this paper that the fatigue threshold value of mode H was 1.9 times of that of mode Ⅰ in dual-phase steel(DPS),and the normal stress intensity factor range oJ mode Ⅱ branch crack tip was 2.2 times of that of mode Ⅰ.Above results illustrate that the resistance of mode Ⅱ crack growth was higher than that of mode Ⅰ,the former resulting from roughness-induced shear resistance,the latter,crack closure. The mode Ⅱ component can play two important roles in near-threshold fatigue crack growth:(1)increasing crack tip plasticity which accelerates the crack growth and(2)intro- ducing crack surface contact and rubbing to reduce the crack propagation rate.By means of crack closure,the quantity of shear resistance was easily solved in this paper.The friction shear stress strength factor range of mode Ⅱ,K_,is still much higher than the closure stress strength factor range of mode Ⅰ,K_(Ⅰ,cl).This illustrated that the roughness enlarged the second role and played a role of shielding crack tip from mode Ⅱ crack.

关键词: mixed-mode(Ⅰ/Ⅱ)fatigue crack growth threshold , null , null , null , null

关于多相材料的研究

材料导报

多相材料是材料研究发展的必然结果。提出多相材料的研究，目的是要拓宽材料研究的视野，主张模糊各类材料的界限，运用纳米材料制备技术，博采各类材料制备工艺之所长，以使用上的要求为材料研究的准则，制作出低成本和高性能稳定性的材料。还强调在考虑材料研究中的问题时，始终以满足使用要求为目标，并不一味地追求材料的高性能，务求创新。提倡用逆向思维来考虑多相材料的研完，研究对象则针对于信息、能源、生物和环保领域的应用。多相材料材料研究About the Research of Multi-phase MaterialsGuo Jingkun (Shanghai Institute of Ceramics,Chinese Academy of Sciences ,Shanghai 200050, China)

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