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Journal of Materials Sciences & Technology
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1991, Vol.7 No.1
Online: 1991-01-28

Articles
 
Articles
1 By ZHANG Mingjie ZHAI Yuchun OIU Zhuxian LIU Honglin CHEN Nianyi Northeast University of Technology,Shenyang,110006.China.Shanghai Institute of Metallurgy,Academia Sinica,Shanghai,200050,China.To whom correspondence should be addressed.
Microstructure of the Ionic Discharge of Oxygen on Graphite Anode in Aluminium Electrolysis
With the SCF-ab initio and EHMO method used in quantum chemistry, the total energy and charge distribution are calculated for O ions which are adsorbed on the different positions of various C lattices. Furthermore, the microstructure is dis- cussed for O ions discharging on the graphite anode.
1991 Vol. 7 (1): 1-8 [Abstract] ( 283 ) [HTML 1KB] [PDF 614KB] ( 292 )
9 By WANG Shuncai LI Chunzhi GAO Yang CAO Chunxiao YAN Minggao Institute of Aeronautical Materials,Beijing,100095,China.To whom correspondence should be addressed.
Phase Transformation and Deformation Mechanism of Ti_3Al-base Alloy
The phase transformation and deformation mechanism of the alloy based on composition Ti_3Al with addition of Nb,V,Mo have been studied by use of transmission electron microscopy (TEM).It has been shown that the orientation relationship of α_2 phase transformed from β phase is:(0001)α_2// (l10)β,[1210]α_2//[111]β.The present dislocation slip systems in α_2 phase are (1100)[0001] and (1100)<1120>.There also exist α_2 twins which have new twin relationship and the twin plane is (2021).
1991 Vol. 7 (1): 9-14 [Abstract] ( 267 ) [HTML 1KB] [PDF 2936KB] ( 274 )
15 By ZHANG Yi WANG Yingxia HUA Tongwen Institute of Chemical Metallurgy,Academia Sinica,Beijing,100080,China.Department of Chemistry,Peking University,Beijing,100871,China.To whom correspondence should be addressed.
Kinetics of α-FeO(OH)Formation in Weak Acidic Medium
The kinetics of α-FeO(OH) formation in weak acidic medium was studied.The effects of the initial concentration,temperature,pH value,partial pres- sure of oxygen,air flow rate and agitating intensity on the oxidation rate of Fe(OH)_2 suspensions have been investigated.It is confirmed that the reaction order for Fe(Ⅱ) is zero at the stage of α-FeO(OH) seeds formation,and about 0.5 at the stage of the seeds growth,and in the whole process partial pres- sure of oxygen appears in first order.The activation energy is determined.The dissolution-oxidation equilibrium which exists in the process of seeds formation has been suggested,by which the zero order reaction for Fe(Ⅱ) and the plateau in the pH-t curve were explained.Physical process is the rate-determining step of the heterogeneous reaction.The study on the kinetics of α-FeO(OH) formation may provide some fundamental informa- tion for the reactor design,the engineering amplifi- cation and the optimization control in the industrial process.
1991 Vol. 7 (1): 15-20 [Abstract] ( 323 ) [HTML 1KB] [PDF 575KB] ( 259 )
21 By FENG Benzheng YANG Deqing Institute of Precious Metals,Kunming,650221,Yunnan,China.Physics Department,Yunnan University,Kunming,China.To whom correspondence should be addressed.
Work Functions of Pd_(83.5)Si_(16.5)and Cu_(70)Ti_(30)Glassy Alloys
The work functions before and after crystallization of two glassy alloys,Pd_(83.5)Si_(16.5) and Cu_(70)Ti_(30) have been measured by means of the con- tact potential difference method in the secondary electron field at room temperature under 10~(-5) Pa vacuum.The results show that the work functions of both glassy alloys are higher than those of the corresponding crystalline alloys.
1991 Vol. 7 (1): 21-24 [Abstract] ( 228 ) [HTML 1KB] [PDF 353KB] ( 243 )
25 By LIU Zhonghua LIU Chunpeng Department of Metallurgy,Kunming Institute of Technology,Kunming,650093,China.To whom correspondence should be addressed.
Reduction Kinetics of Nickel Sulphide
Reduction kinetics of Ni_3S_2 was experimen-tally studied by following the time required forcompletion of the hydrogen reduction reaction inthe presence of calcium oxide.A simple empiricalintegration equation,derived for describing the ef-fect of CaO/S molar ratio,temperature,hydrogenconcentration and the average diameter ofNi_3S_2 grains,may be shown as following:t_(X=1)=2.317×10~(-6)d_(Ni_3S_2) C_(H_2)~(-1)β~(-2.29)e~(13710/T),minThe reduction reaction is of first order with respectto hydrogen concentration,and the apparent reac-tion activation energy is 114.0 kJ/mol.A great ma-jority of metallic Ni reduced from Ni_3S_2 is distrib-uted in the products evenly.
1991 Vol. 7 (1): 25-28 [Abstract] ( 279 ) [HTML 1KB] [PDF 497KB] ( 309 )
29 WU Shanghua LIU Yumen Materials Science Institute,Zhongshan University,Guangzhou,510275,China.Department of Materials Science and Engineering,Xi'an Jiaotong University,Xi'an,710049,China.To whom correspondence should be addressed.
TEM Studies on Martensitic Transformation in Fe-Cr-W-V-C Alloy
The martensitic transformation in Fe-Cr-W-V-C alloy has been investigated by TEM.The habit plane of martensite is near (252)_f, the austenite/martensite orientation relationship is Kurdjumov-Sachs'.In the martensite plates there are twins on (112)[ 1]_b,dislocation tangles and the lattice defects on (011)_b plane.In the austenite near the growing martensite plates,the dislocations with high density and stacking faults can be observed. The substructure of martensite may probably be the result of accommodation deformation during martensitic transformations.
1991 Vol. 7 (1): 29-34 [Abstract] ( 292 ) [HTML 1KB] [PDF 1858KB] ( 277 )
35 XU Yongbo HA Kuanfu WANG Zhongguang YANG Chunsong DAI Zhongling Laboratory for Fatigue and Fracture of Materials,Institute of Metal Research,Academia Sinica,Shenyang,110015,China.Jilin University,Changchun,130023,China.To whom correspondence should be add
Dislocation Behaviour near the Crack Tip in Bulk Fe-3% Si Single Crystal
An investigation has been made of the disloca- tion distribution and dislocation free zone near the crack tip in bulk Fe-3% Si single crystal during deformation in SEM.It has been found that a number of dislocations were emitted from the crack tip during deformation.After that,the dislocations moved rapidly away from the crack tip,which indi- cated that they were strongly repelled by the stress field at the crack tip.Between the crack tip and the plastic zone there is a region of dislocation-free, which is referred to as dislocation-free zone (DFZ). The length of DFZs is roughly estimated 100 μm which is much longer than that found in thin foil specimen.The variation of dislocation density as a function of the distance from the crack tip was measured,which showed that the dislocations are inversely piled up in the plastic zone.The length of DFZs increased with both the length of pre-crack and the amplitude of applied stress.
1991 Vol. 7 (1): 35-39 [Abstract] ( 269 ) [HTML 1KB] [PDF 1047KB] ( 275 )
40 LI Bei YAN Yuxin MENG Guang'en WU Shuangxia TANG Fenghuang Baotou Research Institute of Rare Earth,Baotou,014010,China.To whom correspondence should be addressed.
Effect of Y-containing Phase in Fe-20Cr-4Al-Y Alloys on Microstructure and Embrittlement
In Fe-20Cr-4Al-0.5Si-(0.13-0.73)Y alloys,a new phase consisting of 15.8 wt-% Y,65.4 wt-% Fe,12.6 wt-% Cr,4.4 wt-% Al and 1.4 wt-% Si was observed with its Y-content and crys- tal structure being identical with those of YFe_9 phase basically and the microhardness being 4-5 times higher than that of α-phase matrix.It is a kind of stable particles (2-10 μm) dispersed over the matrix. For Y-free or less alloy,the plasticity dropped sharply after high temperature treatment,while the plasticity is retained for the alloys containing 0.41-0.73 wt-% Y treated below 1340℃,because the Y-containing particles can strongly prevent from grain growth,and dislocation annihilation, and trap impurities.If treatment temperature is higher than 1340℃,however,these actions will dis- appear owing to the melting of the particles.
1991 Vol. 7 (1): 40-46 [Abstract] ( 266 ) [HTML 1KB] [PDF 1821KB] ( 234 )
47 GUO Yunyi ZHANG Xiumu CAO Honglu Institute of Metal Research,Academia Sinica,Shenyang,110015,China.To whom correspondence should be addressed.
Morphology and Effect of Pre-deformation on Martensites by Colored Metaliography August 24,1990
The colored metallography was used to inves- tigate the morphology of martensite in Fe-Ni-C al- loys.By compression deformation martensite trans- forms from lenticular to thin-plate.It is proved that the bended and broken martensites are inher- ent from compressive predeformation of austenite.
1991 Vol. 7 (1): 47-49 [Abstract] ( 268 ) [HTML 1KB] [PDF 726KB] ( 288 )
50 YAN Guongting TA NG Ping ZHANG Shujun Chongqing University,Chongging,630004,China.To whom correspondence should be addressed.
Metallurgical Reaction Characteristic for the Combined Blowing Process of Top-Bottom Blown Oxygen and Bottom Blown Natural Gas
The experiment was carried out in a combined blowing converter.The natural gas was supplied as the cooling medium for the bottom lance.The blow- ing practice of medium P hot metal (0.30-0.85% [P]) indicated that with better stirring at the bottom of the converter and lower P_(CO),this steelmgking process was favorable to reduce the amount of [C] and [O] and increase the (P_2O_5)/[P]. The maximum rate of dephospborization might be high up to 0.0a5%/min and the P content in steel could be reduced to lower than 0.03% by single slag-forming operation.
1991 Vol. 7 (1): 50-54 [Abstract] ( 249 ) [HTML 1KB] [PDF 435KB] ( 469 )
55 XIAO Xingguo LI Jiaxin CAO Tongyou XIAO Zeqiang Northeast University of Technology,Shenyang,110006,China.
Mathematical Model for the Rotary Kiln Process and Its Application
A mathematical model to predict the operation behaviours of the rotary kiln process and to describe the axial distribution of process variables along the length of the reactor has been developed in present work.The model is established based on the principle of mass and heat balance in the system under a steady state with the consideration of kinetic characteristics of the processes.Four examples of the simulation processes in a pi- lot kiln and 3 commercial kilns by using the present mathematical model are given in this paper.The good agreement between the predicted results and the measured data has been obtained.
1991 Vol. 7 (1): 55-64 [Abstract] ( 346 ) [HTML 1KB] [PDF 688KB] ( 1668 )
65 SUI Zhitong XIAO Xingyi HUANG Keqin WANG Changzhen Northeast University of Technology,Shenyang,110006,China.To whom correspondence should be addressed.
Standard Gibbs Free Energy of Formation of Zirconium Oxysulphides
1991 Vol. 7 (1): 65-67 [Abstract] ( 256 ) [HTML 1KB] [PDF 261KB] ( 388 )
68 LI Bencheng Emei Semiconductor Material Factory.Emei,614200,China.
Emei Semiconductor Material Factory
1991 Vol. 7 (1): 68-69 [Abstract] ( 226 ) [HTML 1KB] [PDF 182KB] ( 291 )
69 ZHANG Xiumu
Chinese Conference on Martensitic Transformation(CCOMAT)
1991 Vol. 7 (1): 69-69 [Abstract] ( 213 ) [HTML 1KB] [PDF 71KB] ( 216 )
70
Alatiacts of Seleeted Aitleles on Metals Published in China
1991 Vol. 7 (1): 70-79 [Abstract] ( 222 ) [HTML 1KB] [PDF 4027KB] ( 310 )

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