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
,
null
,
null
,
null
YONG Qilong LI Yongfu Yunnan Institute of Technology
,
Kunming
,
ChinaSUN Zhenbao WU Baorong Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beiiing
,
China YONG Qilong
,
Department of Mechanical Engineering
,
Yunnan Institute of Technology
,
Kunming
,
China
金属学报(英文版)
According to the misfitting dislocation theory,a method of theoretical calculation was devel- oped for the specific energy of the semicoherent interface between microalloy carbonitrides and austenite matrix.The calculating formulae were derived and the results were satisfactorily applied on the research works.
关键词:
specific interfacial energy
,
null
,
null
,
null
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.
材料科学技术（英）
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.
关键词:
work function
,
null
,
null
LU Yuehua Kunming Institute of Precious Metals
,
Kunming
,
ChinaLIU Chunpeng Kunming Institute of Technology
,
Kunming
,
China Research Assistant
,
Laboratory No.1
,
Kunming Institute of Precious Metals
,
Kunming 650031
,
China
金属学报(英文版)
Reaction between Cu_2S and Cu_2O was investigated at 1150 to 1250℃.The reaction rate in- creases with the increase of surface area of Cu_2O grains and depends unobviously on temper- ature.At the suggestion of controlling step of reaction rate being oxygen diffusion through the liquid layer along reaction boundaries,two final kinetical equations would be made as follows: x=6.69×10~(-2)At for 0<α<0.74 and ln(l-α)=-A(9.83×10~(-2)t+1.76)for 0.74<α<1,where α is SO_2 evolved in time t and A is surface area of Cu_2O particles.
关键词:
Cu_2O
,
null
,
null
NING Yuantao Institute of Precious Metals
,
Kunming
,
China Associate Professor
,
Institute of Precious Metals
,
Kunming
,
Yunnan
,
China
金属学报(英文版)
A criterion of the metastable extension of solid solubility was proposed.When the eutectic concentration arm ratio parameter of an alloy,J>10,the hypereutectic extension and the metastable solid solubility limit beyond eutectic concentration may be obtained.When J≤10, the hypoeutectic extension may be obtained.The extension parameter,C_(eq)~s/C_(cu),is directly proportional to the parameter J.Thus,it seems easy to predict the tendency of the solid solu- hility extension under rapid solidification on the basis of the eutectic phase diagram.
关键词:
eutectic system
,
null
,
null
LI Cheng Beijing Central Design and Research Institute for Non-Ferrous Metallurgical Industry
,
Beijing
,
ChinaLIU Chunpeng
,
Kunming Institute of Technology
,
Kunming
,
China LI Cheng
,
Metallurgical Dept.No.l
,
Beijing Central Design and Research Institute for Non-Ferrous Metallurgical Industry
,
Beijing 100038
,
China
金属学报(英文版)
The rate equation of reaction between PbS and PbO is dα/dt=kx_(PbS)~3 x_(PbO)~(-2).A transition product, PbSO_4·2PbO,is found by X-ray diffraction analysis.The reaction mechanism was dis- cussed on the basis of electron transfer.
关键词:
kinetics
,
null
,
null
,
null
,
null
LIU Rixin NING Baolin ** Dept.of Metallurgy
,
Kunming Institute of Technology
,
Kunming
,
650093
,
China*** Dept.of Thermal Energy
,
Northeast University of Technology
,
Shenyang
,
110006
,
China+ To whom correspondence should be addressed
材料科学技术（英）
This paper provides a mathematical model for the billet reheating process in furnace.A new optimum method is brought up that the objective function is the integral value of enthalpy increasing process of a billet.Different delays are simulated and calculated,some proper delay strategies are ob- tained.The on-line computer control model is de- veloped.The real production conditions simulated, the temperature deviation of drop out billet from the target temperature is kept within±15℃.
关键词:
reheating furnace
,
null
,
null
,
null
,
null
NING Yuantao LI Yongnian Kunming Institute of Precious Metals
,
Kunmmg
,
China Professor
,
Kunming Institute of Precious Metals
,
Kunming
,
Yunnan
,
China
金属学报(英文版)
The internal oxidation behavior of Pd-40Ag-1M(M=Zr,Y)alloy wires has been studied in air at 800—1200℃.The relationship between the internal oxidation depth ξ and the reaction time t can be expressed as ξ= Kt~n,where n=0.5—0.75.The higher the temperature,the larger the value of n is.The active elements Zr and Y show different internal oxidation characters.For the alloys eontaining Zr,the oxidation rate along the grain boundaries is about twice as high as that in grains,and“lateral oxidation”exists along the grain boundaries.For the alloys containing Y,the oxidation rates in grains and along the grain boundaries are roughly the same,and there is no“lateral oxidation”along the grain bounda- ries.The activation energies of both alloys are in the range of 120—150kJ/mol.Some prop- erties for oxidized alloys were studied.The mechanisms of the internal oxidation were dis- cussed.
关键词:
Pd-40Ag alloy
,
null
,
null
,
null
,
null
NING Yuantao LI Yongnian Kunming Institute of Precious Metals
,
China Ning Yuantao
,
Professor
,
Institute of Precious Metals
,
Kunming
,
Yunnan
,
China
金属学报(英文版)
The influence of rare-earth elements,La,Ce,Pr,Nd,Sm,Eu,Gd,Dy,Ho,Er and Yb on the thermal stability of PdSi_(16.5) glass was studied systematically by means of DSC.All rare-earth elements,especially heavy ones,increase obviously the thermal stability parameters,including T_θ(T_g ,T_x ,T_g),T_(rg) and ΔE etc.The crystallization temperatures T_(p1) and T_(p2) increase linearly with the lanthanide constriction increasing,but Eu shows an anomalous influence:Pd-Si-Eu metallic glass possesses the highest thermal stability and the lowest concentration limit of glass forming among Pd-Si-R glasses.
关键词:
thermal stability
,
null
,
null
,
null
