材料期刊网

Oxygen Relief/Absorption and Superconductivity of Bi-Pb-Sr-Ca-Cu-O Compounds

QIN Zuoxiang , ZHANG Yansheng , ZHU Naiping Department of Materials Engineering , Dalian Railway Institute , Dalian , 116022 , China.Institute of Metal Research , Academia Sinica , Shenyang , 110015 , China.

材料科学技术（英文）

The oxygen relief/absorption,superconduc— tivity and structure of(Bi_(1-x)Pb_x)_2Sr_2Ca_2— Cu_3O_y compounds have been studied by TGA, electrical resistance measurement and X-ray diffraction.The amount of oxygen which can be re- leased and superconductivity of the compounds are correlative to Pb content.The release of oxygen in- creases when x less than 0.2 and decreases when x exceeds 0.2 with increasing x.The appropriate con- tent of Pb for superconductivity is in the range of 0.1

关键词: oxygen relief/absorption , null , null , null

PRECIPITATION OF TiC IN METASTABLE β-Ti ALLOY

YU Xuejie WANG Jianlin Shanghai Iron and Steel Research Institute , Shanghai , China.HOU Tianjian Anhui Institute of Technology , Hefei , China.YU Xuejie , Senior Engineer , Shanghai Iron Steel Research Institute , 1001 Taihe Road , Wusong , Shanghai , China.

金属学报(英文版)

In order to clarify that the IFP and the “Type 2”α phase are also arising from TiC,a metastable β-Ti alloy was selected for investigation in this work.The results showed that af- ter heating the alloy just below the α+β→β transus temperature and quenching,the TiC lay- er existed at the α/β interface.The morphology of TiC is similar to that of the IFP arising from TiH_2 in the α-β two-phase alloys.The IFP TiC also provided an easy crack path or the crack initiation sites.The fracture is also identical to that caused by IFP TiH_2.The arced diffractions(characteristic of “Type 2”α)were found in the selected area diffraction pat- terns of some specimens which had been isothermally aged after solid solution treatment.The particles which bring on the arced diffractions may be TiC on the basis of structure and lat- tice parameter analysis,not the so called “Type 2”α phase.

关键词: interface phase(IFP) , null , null , null

(α+β)Dual Phase CuZnAl Shape Memory Alloy

ZHAO Xu , QI Min , YANG Dazhi Institute of Metal Research , Academia Sinica , Shenyang , 110015 , China.Department of Materials Engineering , Dalian University of Technology , Dalian , 116012 , China.

材料科学技术（英文）

The effect of α phase on CuZnAl shape memo- ry alloy(SMA)has been systematically studied by electrical resistance method,quantitative measure- ment of micrography and transmission electron microscopy(TEM).It is found that,by controlling the amount of α phase in(α+β)-CuZnAl alloy, phase transformation temperatures can be adjusted precisely in a wide range,while the good shape memory effect of CuZnAl is kept.In a word, quenching from(α+β)dual phase region is a rea- sonable method of adjusting phase transformation temperatures for CuZnAl alloy.

关键词: (α+β)-CuZnAl alloy , null , null

GROWTH OF THERMOELASTIC MARTENSITE

DENG Yongrui University of Science and Technology Beijing , Beijing , China..S.Ansell Colorado School of Mines , Golden , CO 80401 , USA) Associate professor , Department of Materials Science and Engineering , University of Science and Technology Beijing , Beijing 100083 , China.

金属学报(英文版)

The growth of thermoelastic martensite in a Cu-29% Zn-3% Al alloy has been investigated experimentally and theoretically.Metallographie observations showed that the growth oc- cured thermoelastically,i.e.reversibly,in the radial direction as well as in the thickening di- rection.This is not consistent with the theories of Conhen and some others.A model has been suggested to explain the thermoelasticity of the growth.The basic idea is:the elastic strain distribution is highly heterogeneous and the growth is controlled by the local elastic strain en- ergy at the growth frontier area.The calculated results from the model based on Eshelby's theory are consistent with the observations.

关键词: thermoelasticity , null , null

Application of the Hydrogen Diffusion Model to the Hydrogen Permeation

YANG Ke , CAO Mingzhou , WAN Xiaojing , SHI Changxu Institute of Metal Research , Academia Sinica , Shenyang , 110015 , China.

材料科学技术（英文）

The model of hydrogen diffusion formerly de- veloped [1] has been applied successfully to the hydrogen permeation experiment results of three kinds of materials,α—Fe,Fe—Ti alloy and Fe—Ti—C alloy by the mathematical fitting method.From the fitting results it was shown that the model can re- fiect well the diffusion of hydrogen in the materials with trapping.The obtained trapping parameters(α and β)can be used to explain well the diffusion of hydrogen in the samples with trapping.

关键词: hydrogen diffusion , null , null , null

Regular Pattern of Morphology Transition in Mixed Martensite Structures

GONG Hai , ZHANG Xiumu Department of Materials , Dalian Railway Institute , Dalian , 116022 China.Institute of Metal Research , Academia Sinica , Shenyang , 110015 , China.

材料科学技术（英文）

The morphology and substructure of mixed martensites in ferrous alloys have been examined by using optical and transmission electron microscope. The results indicated that the main formation se- quence of martensitic morphology was butterfly→ plate→lath,with decreasing forming temperatures when the plastic accommodation takes place in the parent phase,which is affected by the transforma- tion strain fiélds.It was shown that the martensite morphology is not only decided by the forming temperature alone,but also by the dislocation struc- ture in austenite before the transformation.

关键词: martensite morphology , null , null

Activity of MnO in Blast Furnace-type Slags

ZHOU Jicheng TIAN Yanwen JIANG Zuoyao YANG Shaowei Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China.Northeast University of Technology , Shenyang , China.Jiao Tong University , Shanghai , China.

材料科学技术（英文）

The activity of MnO in blast furnace-type slags CaO-SiO_2,CaO-SiO_2-Al_2O_3 and CaO-SiO_2-Al_2O_3-MgO at 1500℃ has been measured in a graphite crucible with Ag and Sn as solvent metals.The agreement between the values of γMnO obtained from the experimental results using Ag and Sn separately as the solvent metal is excellent.The major errors in the previous studies have proved to be the failure to take into account the exchange reactions involving Si and Mn and insufficient time for the establishment of equilibrium between slag and solvent metal. A new method is suggested for determining the activities of elements in metallic solutions. The method involves the separate equilibration of two metallic alloys,one of which contains the component of interest at a known activity, with a single slag.

关键词: blast furnace slag , null , null

Coercivity Mechanism of Melt-spun Nd-Fe-B Bonded Magnet

HUANG Gangxiang XU Qingzhen GAO Huimin YU Shanfu HUA Hongci WANG Geya Shanghai Iron and Steel Research Institute , Shanghai , 200940 , China.Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , 200050 , China.

材料科学技术（英文）

The microstructures of melt-spun Nd_135- Fe_81.74B4.76 ribbons have been investigated by means of X-ray diffraction,Mossbauer spectroscopy and HREM.Experimental results show that optimal magnetic properties of the bond- ed magnet can be obtained by melt-spun alloys at wheel velocity of 24m/s,the microstructure of which was single phase Nd_2Fe_(14)B crystallites,and no other phases,such as Nd-rich,B-rich or x-Fe phase,were present.It is considered that the high intrinsic coercivity ~iH_c can be attributed to the sin- gle-domain behaviour of Nd_2Fe_(14)B crystallite phase.

关键词: coercivity , null

Measurements of Stress-dependence of Hysteresis in a NiTi Shape Memory Alloy

XU Huibin B.Hinz FU Senlin Technische Universitat Berlin , SG2 , Salzufer 17-19 , W 1000 Berlin 10 , GermanyZhejiang University , Hangzhou , 310027 , China.

材料科学技术（英文）

关键词: martensitic transformation , null , null

Behaviour of Rare Earths in Solid Solution in Steel

LIN Qin , YE Wen , DU Yuansheng , YU Zongsen Department of Physical Chemistry , University of Science and Technology Beijing , 100083 , China.

材料科学技术（英文）

The contents of rare earth metals(REM) in solid solution in 16 Mn steel were determined by means of inductive coupling plasma (ICP) spectroscopy.The amount of REM in solid solution is only a few ppm in the steel with MnS inclusions, which rises slightly with the increasing of REM content in steel.At RE/S>1.9,the MnS inclu- sions in steel disappear completely,the REM con- tent in solid solution increases rapidly with the in- creasing of REM content.The solubility of cerium in 16 Mn steel(st 52)is less than 0.011 wt—% at room temperature. The results obtained indicate that REM in sol- id solution reduce the amount of pearlite and in- crease that of ferrite and its microhardness.Dis- solved REM oculd increase temperature of critical points,alleviate band structnre and suppress growth of austenite grains.

关键词: rare earth , null , null