材料期刊网

EQUILIBRIUM PHASE DIAGRAMS IN SYSTEM CuO-PbO-Ag

SHAO Zhongbao , LIU Kuiren , MENG Bo , LI Ying , YANG Yuqing(Department of Chemistry , Northeastern University , Shenyang 110006 , China) LIU Huakun , DOU Shixue(University of New South Wales , Kensington , Australia)

金属学报(英文版)

Phase equilibrium in the ternary CuO-PbO-Ag system has been investigated using differential thermal analysis(DTA),thermogravimetry(TG),scanning electron microscopy(SEM) and X-ray diffraction(XRD) techniques.In the ternary CuO-PbO-Ag system,there is a eutectic reaction CuO+PbO+Ag=L at 750℃ and a composition of 12.04 mol.% Ag,16.35 mol.% CuO and 71.61 mol.% PbO.Two miscibility gaps near the two binary tie lines PbO-Ag and CuO-Ag were detected. No binary or ternary compound was detected in the ternary system.SEM and energy dispersive spectroscopy(EDS) confirm the presence of two liquid phases and the eutectic point.

关键词: :phase equilibrium , null , null , null , null

BEHAVIOUR OF INITIATION AND GROWTH OF SHORT FATIGUE CRACKS

WU Zhixue , XU Hao(Institute of Mechanical Engineering , Northeastern University , Shenyang 110006 , China)(Fushun Petroleum institute , Fushun 113001.China).(State Key Laboratory for Fatigue and Fracture of Materials , Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110015 , China) Manuscript received 2 July 1995

金属学报(英文版)

Rotary bending fatigue tests were carried out using smooth specimens of a medium-carbon steel with two different grain sizes.The process of early crack development was observed by the replica method,and the effects of grain size and microstructure on short crack development were studied.It was shown that the initiation process of fatigue cracks is that the damaged region is intensified gradually,and the growth of short cracks relates to the coalescence of cracks.The grain size and microstructure have a great influence upon the initiation and growth of short cracks.A reasonable definition was given in relation to short fatigue crack initiation and propagation.

关键词: :fatigue damage , null , null , null

INTRINSIC MAGNETISM AND MAGNETIC ANISOTROPY OF AMORPHOUS Fe_(1-x)(Si,B)_x ALLOYS

GUAN Kehong WANG Jun Northeast University of Technology , Shenyang , China GUAN Kehong , Associate Professor , Dept.of Material Science and Engineering , Northeast Univeristy of Technology , Shenyang 110006 , China

金属学报(英文版)

The magnetic moment and the magnetostriction decrease slightly with the increase of total Si+B content.A maximum of the Curie temperature appears at about 25 at.-% of Si+B.The magnetic anisotropy is uninfluential by the content of Si+B,but much influnce by the demagnetization effect of streak.A qualitative explanation of the experimental phenomenon seems to be noted by the aid of the electron transition and structure model of amorphous al- loys.

关键词: Fe-Si-B alloy , null , null , null , null , null

DIFFUSION BONDING OF SUPERPLASTIC AI ALLOY LC4

HUANG Yan , MA Longxiang Northeast Universtity of Technology , Shenyang , China lecturer , Department of Metalforming , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

Diffusion bonding of supcrplastic Al alloy LC4,with prior surface treatment of organic solution protecting coating after electroplishing and stainless steel wool brushing,was performed by Gleeble test machine under conditions ranged 490—530 ℃,1.0—3.0 MPa. 30—180 min and vacuum of 1.0×10~(-3) Pa.The joints were examined to have similar strength and microstructure to the base metal Discussion was made on the effect of superplastic treatment on bonding.The micromechanism for diffusion bonding of super- plastic metal was suggested as the migration of original bond interfaces caused by atomic diffusion and grain growth. Experimental results for the alloy as quench-aged state were presented to compare with the superplastic one.

关键词: superplasticity , null , null , null

Is the Crystalline Lattice Structure in Nanocrystalline Materials Different from the Perfect Crystal Lattice?

Ke LU National Key Laboratory for RSA , Institute of Metal Research , Academia Sinica , Shenyang , 110015 , ChinaManling SUI Department of Materials Science and Engineering , Northeastern University , Shenyang 110006 , China

材料科学技术（英文）

A thermodynamic analysis of the ultrafine crystallites in nanocrystalline materials was presented in this work.It was deduced that the structure of the nm-sized crystalline grains is different from the perfect crystal lattice,characterized by two possible structure changes;supersaturation of alloy ele- ments and crystal lattice distortion resulted from supersaturation of vacancies.Some experimental ev- idences in the literature,which are in agreement of the thermodynamic consideration,indicate that the structure changes in the nm-sized crystallite seems to be a consequential feature of the nanocrystalline materials.

关键词: nanocrystalline materials , null , null

IMPROVEMENT IN TENSILE PROPERTIES OF α+β TYPE Ti ALLOYS BY HYDROGEN TREATMENT

GONG Bo LAI Zuhan Northeast University of Technology , Shenyang , ChinaNIINOMI Mitsuo , KOBA YASHI Toshiro Toyohashi University of Technology , Toyohashi Japan Department of Physics , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

A new process to refine the microstructure of α+βtvpe Ti alloys was developed by using hydrogen as a temporary alloying element.It involves hydrogenating the alloys below the hydrogenated β transus temperature about 0-40 K,air cooling to room temperature and then dehydrogenating at 948 K.Ti-6AI-4V and Ti-5AI-2.5Fe alloys treated hy this new process show much refined microstructures,and the yield strength,ultimate strength as well as the elongation increase 8—15,5—13 and 7—14% respectively

关键词: Ti-6Al-4V , null , null , null , null

INTERNAL FRICTION OF GRAIN BOUNDARIES IN Fe-P AND Fe-P-La ALLOYS CONTAINING TRACE Cu

JI Jingwen WEI Quanjin GENG Dianqi WU Yuqin Northeast University of Technology , Shenyang , China Professor , Dept.of Physics , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

The grain boundary internal friction(GBIF)in Fe-P and Fe-P-La alloys containing trace Cu has been studied.It is found that an addition of 0.584—0.722 wt-% La obviously reduces the IF,shifts grain boundary peaks towards higher temperatures,and produces a small addi- tional peak at even higher temperature.The mechanism of GBIF is explained as the movement of defects of atomic size,namely point defects,at gram boundaries and/or their clusters un- der stress.

关键词: internal friction , null , null , null , null

PHASE DIAGRAMS OF SYSTEMS SmCl_3-CaCl_2 AND SmCl_3-LiCl

ZHANG Yifeng MENG Bo GU Yunyan Northeast University of Technology , Shenyang , China Professor , Department of Chemistry , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

The phase diagrams of binary systems SmCl_3-CaCl_2 and SmCl_3-LiCl were determined by DTA and X-ray diffraction analysis.The system SmCl_3-CaCl_2 is of a simple eutectic type with eutectic point of 55.8mol-% SmCl_3 at 545℃.The system SmCl_3-LiCl is of the type with incongruent melting phase 2SmCl_3·LiCl at peritectic point 434℃ and with eutectic point of 31.5 mol-% SmCl_3 at 395℃.

关键词: SmCl_3-CaCl_2 , 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

PROPAGATION OF SHORT FATIGUE CRACKS IN STEEL 16Mn

WANG Weiming HUANG Yuhua XU Hao Northeast University of Technology.Shenyang , China Doctorate student , Post Box 175 , Northeast University of Technology , Shenyang 110006 , China

金属学报(英文版)

Small bar speeimens of steel 16Mn with blind-holes were fatigued under constant amplitude Ioadings on a rotathing bending fatigue machie.Short crack propagation emanating from the blind-holes was obtained.Based on the experimental results,an expression of average propa- gation rate of short cracks was proposed.Statistical behavior of short crack propagation was discussed and the evoluation of sutrface sizes of short cracks with fatigue cycle number was al- so given.

关键词: steel 16Mn , null , null , null