Zengqi ZHAO Lab.of Physics
,
Baotou Research Institute of Rare Earth
,
Baotou
,
014010
,
ChinaFeixia CHEN Dazhi YANG Dept.of Mater.Eng.
,
Dalian University of Technology
,
Dalian
,
116024
,
ChinaEr BAO Dept.of Mater.Eng.
,
Yanshan University
,
Qinhuangdao
,
066004
,
China
材料科学技术（英）
Isothermal aging behaviours of a CuZnAl shape memory alloy have been investigated by means of dilatometry.The length of the specimens during isothermal aging from 190 to 280℃ increases with the aging time at each temperature.The isothermal aging kinetics fits in Avrami equation and the time exponent n decreases with the increase in aging temperature.The apparent activation energy for the isothermal aging process was measured to be 109.0kJ/mol,which is about equal to that of a relaxation internal friction peak at about 200℃ (f≈1 Hz) in the alloy.
关键词:
isothermal aging kinetics
,
null
,
null
,
null
,
null
HE Youduo Baotou Institute of Iron and Steel Technology
,
Baotou
,
ChinaY.SAHAI The Ohio State University
,
USA HE Youduo
,
Professor
,
Department of Metallurgy
,
Baotou Institute of Iron and Steel Technology
,
Baotou
,
China
金属学报(英文版)
The influence of some factors on velocity field in continuous casting tundishes has been veri- fied by means of computer simulation.These factors are tundish wall inclination;the dimensionless geometric size of tundish,the double inclined wall tundish;the dimension and location of weir and dam.
关键词:
continuous casting tundish
,
null
WANG Wenmei Baotou Research Institute of Rare Earth
,
Ministry of Metallurgy Industry
,
Baotou
,
ChinaYU Yongfu CHEN Quanyuan Changsha Institute of Mining and Metallurgy
,
Ministry of Metallurgy Industry
,
Changsha
,
China engineer
,
Baotou Research Institute of Rare Earth
,
Ministry of Metallurgical Industry
,
Baotou 014010
,
China
金属学报(英文版)
Based on theoretical calculation of electronegativity of groups of flotation reagent and method of infrared adsorption spectroscopy,the collection and adsorption of α-nitroso-β- naphthol in hematite flotation have been studied.The chemical adsorption seems to be predominant owing to formation of pentacyclic nitrosyl chelate compound by atoms of nitrosyl bond in α-nitroso-β-naphthol together with Fe(Ⅲ)on hematite surface.Mean- while,the nonuniform multilayer physical adsorption is also occurred.
关键词:
α-nitroso-β-naphthol
,
null
,
null
,
null
,
null
ZHAO Zengqi CHEN Feixia YANG Dazhi BAO Er ** Physical Laboratory
,
Baotou Research Institute of Rare Earth
,
Baotou
,
014010
,
China*** Dept.of Materials Engineering
,
Dalian University of Technology
,
Dalian
,
116024
,
China**** Dept.of Materials Engineering
,
Yanshan Uni
材料科学技术（英）
The present investigation showed that the re- laxation peak at about 200℃ (f≈1Hz) was related to bainitic transformation in a CuZnAl alloy.The peak decreased when bainite precipitated.The activation energy of the peak was the same as the apparent activation energy of bainitic transforma- tion.According to the relations between the peak and the bainitic transformation,the mechanism of the peak has been discussed.
关键词:
internal friction
,
null
,
null
,
null
QI Yunxin Nei Monggol Institute of Metallic Materials
,
Baotou
,
China QI Yunxin
,
Professor
,
P.O.Box No.4
,
Baotou 014034
,
Nei Monggol
,
China
金属学报(英文版)
The nitride in 30CrNi steel and its composition along boundaries have been studied by means of scanning Auger microprobe.The nitride identified metallographically is Zr(C,N)which contains a small amount of Ti and O.The interface width between the Zr(C,N)and the matrix is about 1.6 μm.An Fe-rich shell is.found on the surface of Zr(C,N)which appeared on the fracture surface.The thickness of shell is 0.1-0.8μm.The Fe concentration of its outmost layer is 3-18 at.-% and decreases exponentially along the depth direction.
关键词:
nitride
,
null
,
null
,
null
,
null
LI Bei WU Shuangxia LI Dianchen Baotou Research Institute of Rare Earth Ministry of Metallurgical Industry
,
Baotou
,
ChinaMA Ruzhang University Science and Technology Beijing
,
Beijing
,
China Baotou Research Institute of Rare Earth
,
Ministry of Metallurgical Industry
,
Baotou 014010
,
China
金属学报(英文版)
A high temperature embrittlement occures in Fe-15Cr-4AI and Fe-20Cr-4Al alloys treated over 1000 C.It is caused mainly by 475℃ brittleness during cooling.When a secondary treatment at 500℃ was conducted,the 475℃ brittleness developed very rapidly.After only 15 rain of the treating,little plasticity was remained for all samples pretreuted at the temper- atures over 1000℃ and cooled in water.However,no 475℃ brittleness was generated when pretreating temperature was below 1000℃,Addition of Yttrium can inhibit not only grain growth,but also 475℃ brittleness.For the alloys with 0.2—0.4 wt-%Y,after treating at 800—1300℃,the plasticity did not decrease and the properties of furnace cooled samples were not lower than those of water cooled samples.
关键词:
Fe-Cr-Al alloy
,
null
,
null
WANG Jixin Baotou Research Institute of Rare Earth
,
Ministry of Metallurgical Industry
,
Baotou
,
China Senior Engineer
,
Baotou Research Institute of Rare Earth
,
P.O.Box 131
,
Baotou 014010
,
China
金属学报(英文版)
In the light of estimation model for ternary excess properties,an approximate analytical procedure for ternary Gibbs-Duhem equation was proposed,and verification by previous ternary systems as Cd-Bi-Pb and Zn-In-Cd was also made.
关键词:
Gibbs-Duhem equation
,
null
REN Jun Baotou Research Institute of Rare Earth Metals
,
Ministry of Metallurgical Industry
,
Baotou
,
China engineer
,
Baotou Research Institute of Rare Earth Metals
,
Baotou 014010
,
China
金属学报(英文版)
The flotation behaviour and mechanism of bastnaesite with N-hydroxyl phthalicimide were investigated by ξ-potential measurement,infrared spectrum and quantum chemistry calculation.The results show that 3 oxygen atoms from N-hydroxyl phthalicirnide chelate the rare earth ions on the surface of bastnaesite to form double five-chain O=C-N-O- RE(Ⅲ)-O chelate which is chemically adsorbed on the surface of bastnasite,thus making N-hydroxyl phthalicimide an effective collector for bastnaesite.
关键词:
N-hydroxyl phthalicimide
,
null
,
null
,
null
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.
材料科学技术（英）
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.
关键词:
Fe-Cr-AI-Y alloy
,
null
,
null
QI Yunxin TANG Wentai XIA Jianguo Nei Mongol Institute of Metallic Materials
,
Baotou
,
ChinaLI Wang ZHAN Zhenzong Institute of Physical and Chemical Engineering Research
,
Tianjin
,
China
金属学报(英文版)
The surface segregation of substrate elements through the Au layer in the Au-Ni-Kovar sys- tem specimens heated at 250—350℃ for 0.5—1.5 h has been studied by SAM and XPS. Visual evidence of the mechanism for Ni and Co surface segregation of the complicated sys- tem has been given,i.e.Ni and Co penetrated the gold layer mainly by grain boundary diffu- sion and then covered the Au layer by surface diffusion.The strdy results of the chemical states of surface segregation elements not only indicate that oxygen adsorption and oxidation reaction are the driving force for the surface segregation of Ni and Co,but also show that the above segregation can result in water absorption on surfaces.
关键词:
Au-Ni-Kovar alloy system
,
null
,
null
,
null
,
null
