材料期刊网

SYNTHESIS OF ULTRAFINE PLZT POWDER BY A SIMPLE CO- PRECIPITATION METHOD

H. Ying1) , X. D. Sun1) , Q. B. Yang1) , J. B. Li2) , Y. M. Wang2) , Z. Zhang3) and J. You3)1) School of Materials and Metallurgy , Northeastern University , Shenyang 110006 , China2) Departm ent of Materials , School of Mechanical Engineering , Shenyang University , Shenyang110044 , China3) Liaoning Analyzing and Testing Research Center , Shenyang 110015 , China

金属学报(英文版)

Starting from cheap inorganic salts , ultrafine P L Z T po w ders were synthesized by a co pre cipitation m ethod . The results show that the precursor precipitate obtained by the co precipita tion method transfor ms co m pletely to P L Z T phase by calcining at 420 ℃ for 4 hours , about300 ℃low er than the nor m al transform ation te m perature of P L Z T obtained by m ixed oxidemethod . The effect of residual N H4 N O3 in the precursor precipitate on transfor m ation te m perature of the P L Z Tpow der w as investigated . The residual N H4 N O3 in the precursor po w der can reduce further the P L Z Ttransfor m ation tem perature to about 300 ℃, but a sm alla mount of Zr O2 and Pb Ti O3 re m ained . By a proper control of the synthesizing route , a P L Z T po w der with a pri m ary particle size of 10 n m and an agglom eration size of 0 3 μm hasbeen produced .

关键词: P L Z T , null , null

A COMPREHENSIVE INVESTIGATION ON A PECULIAR DEFECT IN WURTZITE GaN FILM

S.Q.Wang1 , 2) and H.Q.Ye1) 1) Laboratory of Atomic Imaging of Solids , Institute of Metal Research , The Chinese Academy of Sciences , Shenyang 110015 , China 2)Department of Materials Science and Metallurgy , University of Cambridge , Cambridge CB2 3QZ , UK

金属学报(英文版)

Apeculiar crystal defect was observed by experiment of high resolution electron microscopy( HREM) .It wasidentifiedtoformed bytwothreading dislocationsand asegmentof(11 20) domain boundary. An atomicstructure model was proposed for the anomalous defect. Theresultofthe weak beam experimentofelectron microscopeaffirmedthesuggested model.Thestructuralpropertiesofseveral GaN(11 2 0) domain boundaries werestudied by Molec ular Dynamicscalculations. Thetheoreticalresultsshowedthatthelike atom bonding domain boundary, whichcomposesthe main partofthe peculiar defect, has much higher formationenergy than itcounterpartof unlike atom bonding domain boundary. Theoutcome providesanotherevidenceforthesuggested model.

关键词: HREM , null , null , null , null

FAREY SEQUENCE OF NONLINEAR DIFFERENTIAL DYNAMIC SYSTEM IN TWO DIMENSIONS

H. Q. Jin and S. N. Xu Shenyang Institute of Technology , Shenyang 110015 , China

金属学报(英文版)

In this paper , through the discrim ination of Farey sequence in the forced Brusselator withweak coupling , it is proved that there is a topological translation fro m a nonlinear differen tial system ( limit cycle) to the circle m ap .

关键词: non - linearity , null , null , null

The effect of environmental variables on atmospheric corrosion of carbon steel in Shenyang

Chinese Science Bulletin

A study was carried out in order to investigate the effect of contaminants and meteorological variables on the rust layer of carbon steel exposed in Shenyang urban atmosphere. Seven kinds of contaminants and twelve kinds of meteorological parameters were also registered in order to correlate the data with respect to corrosion rate and the stepwise multiple regression analysis was carried out in order to obtain the best regression model. The sum of rainfall time as well as sunshine time and the concentration of H(2)S could stimulate initial atmospheric corrosion of carbon steel. The initial atmospheric corrosion kinetics of carbon steel was observed to follow the cubic equation. The corrosion products were analyzed by XRD and the transformation of phases in different periods was discussed.

关键词: contaminants;meteorological parameters;carbon steel;urban atmospheric;corrosion;stepwise multiple regression;corrosion products;rust;pollution

在碳钢墓材上激光熔覆玻璃涂层及其物理化学行为研究

喻家庆

腐蚀学报（英文）

在碳钢墓材上激光熔覆玻璃涂层及其物理化学行为研究喻家庆(中国科学院金属腐蚀与防护研究所九三届博士,沈阳110015)LASERCLADGLASSCOATINGSONSTEELSANDTHEIRPHYSICAL—CHEMICALBEHAVIORS$(AstractofDissertationforDoctorofEngineeringatInstituteofCorrosionandProtectionofMetals,TheChineseAcademyofSciences,Shenyang110015)b

关键词:

The fourth editorial committee meeting of JMST was held in Shenyang, China

材料科学技术（英文）

关键词:

CRYOGENIC MECHANICAL BEHAVIOUR OF MARAGING STEEL CONTAINING HYDROGEN

LIU Zhonghao CHEN Lian Institute of Metal Research , Academia Sinica , Shenyang , China

金属学报(英文版)

Within the range of 77 to 295 K,the strength and plastieity of 18Ni maraging steel increase with decreasing temperature and decrease with increasing hydrogen content.The susceptibility to hydrogen embrittlement of the maraged specimens is superior to solid solution ones.The dislocations after plastically deforming will tangle into dislocation cells which reduce thermselves in size as the temperature decreases,and coarsen as the hydrogen content in- creases.No cryogenie deformation twin was found.The tensile fracture surfaces of the solu- tion and maraged specimens containing 5.90 ppm hydrogen under 295 to 223 K are revealed as quasi-cleavage and intergranular features respectively and as transgranular ones under other experimental conditions.The influence of hydrogen on the mechanical behaviour of steel and the mechanism of hydrogen induced deformation and fracture are discussed. Research Assistant, Institute of Metal Research,Academia Sinica, Shenyang 110015,China

关键词: maraging steel , null , null , null

METALLOGRAPHIC STUDY ON SEGREGATION BEHAVIOUR OF P IN COLD-ROLLED Fe-P ALLOYS DURING ANNEALING

NING Hua ZHANG Lixin Institute of Corrosion and Protection of Metals , Academia Sinica , Shenyang , China

金属学报(英文版)

The segregation behaviour of P and its effect on structure of 70%-reduction cold rolled Fe-P alloys containing different contents of P,e.g.,0.007,0.06 and 0.09% P,during annealing at 200-700℃ under vacuum have been studied by means of metallography and EPMA.The P was found to segregate preferentially along dislocation line during recovery annealing.The P-riched dislocation densing region,the P-depleted region and the sub-grain-like boundary thus formed.The nuclei grow preferentially during recrystallization in such region that the P segregation is more evident and the residual strain by dislocation densing increases to large extent.After recrystallizing,the P segregates along grain boundaries and makes the grains in alloy fine. Engineer,Institute of Corrosion and Protection of Metals,Academia Sinica,Shenyang 110015,China

关键词: P , null , null , null

Characterisation of initial atmospheric corrosion carbon steels by field exposure and laboratory simulation

Corrosion Science

The early stages of the evolution of atmospheric corrosion of carbon steels exposed in both a laboratory simulated and a natural atmosphere environment in Shenyang have been observed by in situ scanning electron microscopy. In the case of laboratory cyclic wet-dry tests, even though the chloride content level is very low, filiform corrosion is initiated in the early stage. The filiform corrosion grows in random directions, forming a network of ridges. White nodules nucleate and grow on the ridges during continued corrosion and eventually connect with each other to form the initial corrosion scale. Pits were also found on the surface beneath corrosion products. In the case of a natural atmospheric environment, both filiform corrosion and other localized corrosion, such as pitting and inter-granular attack take place in the initial stage. It is obvious that there is variety of localized corrosion in the initial stage of atmospheric corrosion. (C) 2007 Elsevier Ltd. All rights reserved.

关键词: steel;atmospheric corrosion;initial stage;localized corrosion;in-situ;iron;electrolyte;thickness

原位生成金属间化合物/Fe-Cr-Ni复合材料的耐蚀性

杨霓虹 , 柯伟 , 张玉生

中国腐蚀与防护学报

原位生成金属间化合物／Ｆｅ－Ｃｒ－Ｎｉ复合材料的耐蚀性杨霓虹，柯伟，张玉生（西南交通大学成都６１００３１）（中国科学院金属腐蚀与防护研究所沈阳１１００１５）１前言铬、镍和铝含量很高的铁基合金在一定条件下可生成大量均匀分布的金属间化合物，形成原位生成的金属间化合物／Ｆｅ－Ｃｒ－Ｎｉ复合材料ｌ‘］．金属间化合物具有很高的硬度，而且耐蚀性良好，同具有优良耐蚀性的Ｆｅ－Ｃｒ－Ｎｉ合金基体复合所形成的?...

关键词: null , Intermetallics / Fe-Cr-Ni composite , Passivity