SUN Enxi Dalian Railway College
,
Dalian
,
ChinaYANG Dazhi Dalian University of Technology
,
Dalian
,
ChinaXU Zuyao (T.Y.Hsu) Shanghai Jiaotong University
,
Shanghai
,
ChinaYANG Fuming ZHAO Ruwen Institute of Physics
,
Academia Sinica
,
Beijing
,
China YANG Dazhi
,
Professor
,
Dalian University of Technology
,
Dalian 116024
,
China
金属学报(英文版)
The pulsed magnetic field induced martensitic transformation with isothermal and athermal kinetics in Fe-2Ni-4Mn(wt-%)alloy has been studied by means of magnetization measurements,optical microscopy and thermodymical analyses.It is shown that there exits a critical magnetic intensity for induing martensitic transformation at a given temperature above Ms.The critical magnetic field increases linearly with increasing ΔT= T-M_S.The magnetic field strongly promotes the athermal martensitic transforamtion and restrains the isothermal one.The entropy change ΔS for athermal transformation at Ms is 4.13 J/mol· K.The effect of magnetic field on martensitic transformation in Fe-21Ni-4Mn alloy is main- ly due to Zeeman effect.Lath,plate and butterfly martensities were observed under magnetic field.
关键词:
magnetic field-induced martensitic transformation
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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
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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
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null
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YI Huchun GE Tingsui (T.S.Ke) Institute of Solid State Physics
,
Academia Sinica
,
Hefei
,
China GE Tingsui
,
Professor
,
Laboratory of Internal Friction and Defects in Solids
,
Institute of Solid State Physics
,
Academia Sinica
,
Hefei
,
China
金属学报(英文版)
Internal friction and elastic modulus of ternary Mn-Cu-Al alloys containing 56—60 wt-% Mn,0-3.59 wt-% Al were measured with acoustic frequency,1 kHz,in the tempera- ture range of-150 to 150℃.It was found that when the specimen was aged in the temperature range under the spinodal curve within the miscibility gap(400—500℃),the internal fric- tion increases with an increase of the aging time and reaches a maximum value at a certain ag- ing time which is shorter with a higher aging temperature.Two internal friction peaks which did not appear before the aging were observed above room temperature after a definite aging time.These are respectively the martensitic tranformation peak and the relaxation peak orig- inating from the stress-induced movement of the twin boundaries.The former peak shifts to- ward higher temperatures with an increase of the aging time,whereas the relaxation peak ap- pearing at 15℃,is independent of the aging time and temperature.The activation energy as- sociated with the relaxation peak was found to be 0.56 eV which is about the same as that of the relaxation peak in binary alloy containing 90 wt-% Mn.It was also found that the hardness,strength and the brittleness of the specimen increase when aged below the spinodal curve within the miscibility gap.The addition or Al enhances the strength but reduces the in- ternal friction of the specimen.A choice of suitable aging time and temperature can give an optimum compromise of high strength and high internal friction.Analysis of experimental re- sults suggests that spinodal decomposition leads to Mn-rich zones in the specimen and thus causes the phase transformation and the change of mechanical properties of the specimen.
关键词:
internal friction
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NING Xiuzhen ZHANG Tianxiang TONG Yingjie ZHU Yaoxiao Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China [Originally published in ACTA METALL SIN(CHINESE EDN)25(3)1989 pp A196—A200
,
ZHU Yaoxiao
,
Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China
金属学报(英文版)
A new point of view on the homogenization treatment has been proposed.It is supposed that a little liquid in the alloy may promote the homogenization process in some aspects and reduce the time for eliminating the Laves-phase in alloy GH169.The microprocess of the elimination of Laves-phase in the case of a little liquid existing in the alloy has also been described.
关键词:
alloy GH169
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YANG Dazhi ZHU Min Dalian Institute of Technology
,
Dalian
,
Liaoning
,
China. YANG Dazhi
,
Professor
,
Dept.of Mater.Sci.and Eng.
,
Dalian Institute of Technology
,
Dalian
,
Liaoning
,
China
金属学报(英文版)
The substructural development of martensite plates at different stage of the transformation for an Fe-21Ni-4Mn alloy has been investigated by using transmission electron microscope. Twinning was found in small thin platelets at the initial stage.Fine twins extend to the whole platelet.The dislocations and twins were found in the thick platelets at a later stage.Bending of the twins was also observed frequently at this stage.Finally,several platelets coalesce with each other to form a macroscopic(252)_f martensite“plate”.The original habit plane of the individual platelet was measured to be close to(121)_f.
关键词:
Fe-Ni-Mn alloy
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CHEN Rongzhen ZHANG Hanxing ZHENG Jianxuan Guangxi University
,
Nanning
,
ChinaHE Hanping Guangxi Research Institute of Nonferrous Metals and Geology
,
Nanning
,
China CHEN Rongzhen
,
Professor
,
Department of Physics of Guangxi University
,
Nanning
,
Guangxi 530004
,
China
金属学报(英文版)
The 410℃ isothermal section of the phase diagram of Al-Cu-Sb ternary system has been de- termined by means of X-ray powder diffraction method and electron probe microanalysis. The section determined consists of 12 single-phase regions,21 bi-phase regions and 10 tri-phase regions.
关键词:
Al-Cu-Sb ternary system
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GUO Jianting LI Hui SUN Chao ZHU Yaoxiao Institute of Metal Research
,
Academia Sinica
,
Shenyang
,
China GUO Jianting
,
Professor
,
Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
China
金属学报(英文版)
The microstructure and the mechanical properties from room temperature up to 1050℃ of Ni_3Al alloys containing 0—0.6 at.-%Zr,0—7.7 at.-%Cr and 0—2.22 at.-%B have been studied.It was found that the temperature dependence of their yield strength variation reveals to be anomalous,i.e.the strength increases with the temperature raising,and then decreases till it surpassed the peak value.Both Zr and Zr+Cr may improve the yield strength of the al- loys in the entire range of testing temperatures,as well as the tensile strength and elongation under high temperatures.B is favourable to raise the tensile and yield strengths of the alloys, and also plasticity.But the strength will reduce as B added is over 2.22 at.-%.The Ni_(20)Al_3B_6 and Ni_3Al eutectic mixture like islands and globes precipitated inside the grains and along the grain bounderies,which are harmful to the strength and ductility,may be formed when the B content exceeds the limit of solubility.
关键词:
Ni_3Al
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QIAO Zhiyu WANG Mingsheng ZHENG Chaogui DUAN Shuzhen University of Science and Technology Beijing
,
Beijing
,
China Qiao Zhiyu
,
Professor
,
Dept.of Physical Chemistry University of Science and Technology Beijing
,
30 Xueyuan Road
,
Beijing 100083
,
China
金属学报(英文版)
PrCl_3-NaCl-LiCl phase diagram has been constructed from the phase diagrams of its sub-binary systems and of six quasi-binary systems measured by DTA technique.It is found that this ternary system is composed of five liquidus surfaces,seven second crystallization lines,two peritectic points and one eutectie point.The temperatures and compositions of invariant points are as follows:P_1(416℃,30.3 mol% NaCl,44.2 mol% LiCl,25.5 mol% PrCl_3);P_2(409℃,25.0 mol% NaCl,50.0 mol% LiCl,25.0 mol% PrCl_3);E(404℃,20.0 mol% NaCl,55.4 mol% LiCl,24.6 mol% PrCl_3).
关键词:
PrCl_3-NaCl-LiCl
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null
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ZHANG Qiyun LIU Shuqi LAN Tie FU Yuchuan Peking University
,
Beijing
,
China ZHANG Qiyun
,
Professor
,
Department of Chemistry
,
Peking University
,
Beijing
,
China
金属学报(英文版)
A study on the interfacial activity behavior of flux during aluminium brazing has been made by using metallography,SEM and electron prob techniques.The results show that the activity, of a flux is caused by the wetting of base metal with the liquid heavy metal reduced from the flux,thus,some regions of liquid alloy created,at which no aluminium oxide film covers on the surfaces.The reduced metal drops are finally trapped in the fillet.The size of the metal drops increases with the decrease of brazing temperature.
关键词:
aluminium brazing
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