Calculation of Valence Electron Structure of Precipitate Phases in Al-Cu Cast Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 758-763
Author(s):  
Chang Tian ◽  
Rui Chun Wang ◽  
Run Xia Li ◽  
Rong De Li
Keyword(s):  
Valence Electron ◽  
Cast Alloy ◽  
Electron Structure ◽  
Electron Theory ◽  
Valence Electron Structure ◽  
Electron Pairs ◽  
Length Difference ◽  
Empirical Electron Theory ◽  
Structure Factors ◽  
Thermal Stability Of

Based on Empirical Electron Theory in solid (EET) and Bond Length Difference (BLD) the valence electron structures of precipitates in AlCu alloy during aging process were calculated. The results show that the different phase structure factors explain the thermal stability of phases in θ sequence, and the tendency of atoms solution is corresponding with the phase transition during aging from valence electron structure levels, which reveals the inside causes of ageing hardening is closely related to the covalent electron pairs in some bond of the precipitations and matrix.

Theoretical Calculation of the Polytypism Transition Temperature of Titanium Alloys on the Valence Electron Level

2012 ◽  
Vol 152-154 ◽  
pp. 342-347
Author(s):  
Hua Qu ◽  
Wei Dong Liu
Keyword(s):  
Transition Temperature ◽  
Titanium Alloys ◽  
Valence Electron ◽  
Pure Titanium ◽  
Electron Theory ◽  
Electron Level ◽  
Valence Electron Structure ◽  
Electron Pairs ◽  
Stable Element ◽  
Empirical Electron Theory

Based on the polytypism transition temperature(PPT) of pure titanium, the the empirical electron theory of solids and molecules(EET) and the basic theory of the phase transformation of titanium alloys, a new method to calculate the PTT of titanium alloys is put forward after calculating the valence electron structure(VES) parameter nA which is the covalence electron pairs on the strongest bond of alloy phases, the crystal cell weight of  and  phases in the structure, the compensation coefficient of the phase and the temperature coefficient of  stable element. After calculating the PTT of some common titanium alloys, we find that the theoretical values are consistent with the experimental ones, so it is feasible to calculate the polytypism transition temperature of the titanium alloys on the covalence electron level.

Influence of Micro-Addition Chromium on the Valence Electron Structure and Toughness of Fe2B Phase

2010 ◽  
Vol 34-35 ◽  
pp. 1135-1139
Author(s):  
Rui Na Ma ◽  
Yong Zhe Fan ◽  
Xiao Ming Cao ◽  
Ming Wen
Keyword(s):  
Fracture Toughness ◽  
Valence Electron ◽  
Chromium Content ◽  
Electron Structure ◽  
Valence Electron Structure ◽  
Electron Pairs ◽  
Good Corrosion Resistance ◽  
Length Difference ◽  
Fe2b Phase ◽  
Good Agreement

Fe2B is a kind of typical intermetallic compound, which has good corrosion resistance in molten zinc. However, the fatal intrinsic brittleness limits its further application in the Hot-Dip Galvanizing Industry. Therefore, it is worthwhile to improve the toughness of Fe2B phase. In this study, the fracture toughness property of Fe2B phase with and without micro-addition chromium is investigated. In comparison with pure Fe2B phase, the intrinsic brittleness of Fe2B phase with chromium is lower. In addition, the valence electron structure of Fe2B containing various chromium content is calculated by the method of bond length difference (BLD). The results show that, in the (Fe1-x Crx)2B phase, the number of covalent electron pairs and the weaker bond energy are increased by the substituting atom-Cr. The calculated results are in good agreement with experimental observations.

The Valence Electron Structure of High-Entropy Alloys

2017 ◽  
Vol 1142 ◽  
pp. 3-7
Author(s):  
Bo Cheng ◽  
Yun Kai Li ◽  
Gui Qin Hou
Keyword(s):  
Valence Electron ◽  
Electron Pair ◽  
Electron Structure ◽  
High Entropy Alloys ◽  
Electron Theory ◽  
Valence Electron Structure ◽  
High Entropy ◽  
Melting Temperatures ◽  
Empirical Electron Theory ◽  
Pair Number

Empirical Electron Theory in Solids and Molecules (EET) was used to analyze the valence electron structure of ZrTiHfVNb, ZrTiHfVTa and ZrTiHfNbMo high-entropy alloys. The parameters characterizing the valence electron structure of high-entropy alloys were calculated, which were used to discuss the hardness and melting temperature of high-entropy alloys. The results show that the hardness of high-entropy alloys is positively correlated to the shared electron pair number in valence electron structure. The theoretical melting temperatures of high-entropy alloys were predicted by the parameters characterizing the valence electron structure.

ANALYSIS OF VALENCE ELECTRON STRUCTURE ONFe3AlCxPRECIPITATED FROM C-ALLOYED IRON ALUMINIDES

2013 ◽  
Vol 20 (01) ◽  
pp. 1350005 ◽  
Author(s):  
XIAO-FENG TIAN ◽  
WEI-KE ZHANG ◽  
YU QI
Keyword(s):  
Valence Electron ◽  
Theoretical Explanation ◽  
Electron Structure ◽  
Iron Aluminides ◽  
Electron Theory ◽  
Valence Electron Structure ◽  
Alloyed Iron ◽  
Empirical Electron Theory ◽  
The Matrix ◽  
Brittle Phase

Carbides of Fe3AlCxprecipitated from iron aluminides can strengthen the matrix; the empirical electron theory (EET) was applied to analyze the attribute of carbides in the paper, giving theoretical explanation on the matrix and precipitation. Valence electron structure (VES) of Fe3AlCxwas studied in detail, comparison with the iron aluminides matrix, the hard and brittle phase of Fe3AlCxcan be interpreted form the viewpoint of valence electron structure.

Theoretical Calculation of β Transition Temperature of Ti-6Al-4V from Valence Electron Level

2011 ◽  
Vol 299-300 ◽  
pp. 592-595
Author(s):  
Hua Qu ◽  
Wei Dong Liu
Keyword(s):  
Transition Temperature ◽  
Theoretical Calculation ◽  
Titanium Alloys ◽  
Valence Electron ◽  
Electron Theory ◽  
Electron Level ◽  
Valence Electron Structure ◽  
Electron Pairs ◽  
Stable Element ◽  
Empirical Electron Theory

Based on the empirical electron theory of solids and molecules and the basic theory of the phase transformation of titanium alloys, a new method to calculate β transition temperature of titanium alloys is put forward after calculating the valence electron structure(VES) parameternAwhich is the covalence electron pairs on the strongest bond of alloy phases, the crystal cell weight of a and b phases in the structure, the compensation coefficient of the phase and the temperature coefficient of b stable element. After calculating we find β transition temperature of Ti-6Al-4V is 974.9 °C, the error of the theoretical calculation value and the experimental one(995 °C) is 2%, so it is feasible to calculate β transition temperature of the titanium alloys from covalence electron level.

Research of Cr1-xMxN's (M=Al,V,Ti,etc.,x=0.5) Coating Valence Electron Structure Calculation and Wear-Resisting Performance

2013 ◽  
Vol 706-708 ◽  
pp. 238-243 ◽  
Author(s):  
Tao Tao Fan ◽  
Wen Kai Xiao ◽  
Liang Li ◽  
Si Lan ◽  
Xiao Tuo Li
Keyword(s):  
Phase Space ◽  
Valence Electron ◽  
Phase Interface ◽  
Structure Calculation ◽  
Electron Structure ◽  
Electron Theory ◽  
Valence Electron Structure ◽  
Empirical Electron Theory ◽  
Phase Out ◽  
Coating Matrix

Based on empirical electron theory of solid and molecule (EET, Empirical Electron Theory of Solids and Molecules) ,this paper calculated the Cr1 – xMxN molecular coating’s valence electron structure of the phase space and the valence electron structure of coating matrix phase out of phase interface. By analysing microscopic valence electron structure, we discussed the alloy elements’ influence on this series of coatings’ resistance. And we found that V elements can significantly increase the metal chromium nitride’s were resistance , element Ti takes the second place, element Al also has some effect.

Analysis of Valence Electron Theory on the Catalytic Mechanism of Diamond Single Crystal Growth

2007 ◽  
Vol 353-358 ◽  
pp. 2998-3001 ◽  
Author(s):  
Li Li ◽  
Bin Xu ◽  
Mu Sen Li ◽  
Jian Hong Gong
Keyword(s):  
Electron Density ◽  
Valence Electron ◽  
Catalytic Mechanism ◽  
Diamond Structure ◽  
Dirac Theory ◽  
Electron Theory ◽  
Valence Electron Structure ◽  
Large Numbers ◽  
Empirical Electron Theory ◽  
Structure Factors

Large numbers of experimental results show that carbides Me3C (Me means Fe, Ni, Co, Mn) are the primary carbon source to form diamond structure under the high temperature and high pressure (HPHT). In this paper, based on the empirical electron theory of solids and molecules (EET), the valence electron structure (VES) and interface structure factors of diamond and various carbides are calculated, and the boundary condition of electron movement in the improved Thomas- Fermi-Dirac theory by Cheng (TFDC) is applied to the carbide/diamond interfaces. It is found that the electron density of crystal plane in Me3C formed by C-C bonds is continuous with that in diamond at the first order of approximation. Compared with Ni-based carbides [Ni3C, (NiMn)3C)], the electron density difference of Fe-based carbides [Fe3C, (FeNi)3C, (FeMn)3C]/diamond interfaces is lower, and that of (FeNi)3C/diamond interface is minimum. The results show that the energy needed to transform carbon atomic groups into diamond structure is lower for Fe-based carbides than Ni-based carbides.

Electron Structure and Interface Energy of GP Zone in Al-Zn Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 3131-3136 ◽  
Author(s):  
Ying Jun Gao ◽  
Yongjian Han
Keyword(s):  
Valence Electron ◽  
Metastable Phase ◽  
Covalent Bond ◽  
Interface Energy ◽  
Electron Structure ◽  
Electron Theory ◽  
Valence Electron Structure ◽  
Empirical Electron Theory ◽  
Zn Alloy

The valence electron structure of GP Zone in Al-Zn alloy was calculated according to the Empirical Electron Theory(EET). The result of valence electron structure was further applied to analyze the interface energy between GP Zone and matrix. The reason that the GP Zones were formed even at the highest quenching speed and the hardness was stably ascended as soon as GP zones were formed and reached the maximum before the precipitation of metastable phase, was that the amoumt of the strongest covalent bond in the GP Zone was far more than that in α-Al cell and the Al atom in GP Zone was easily prone to forming covalent bond with Zn atom. It was an easy and effective method to apply the EET theory with the hardball model to calculation of interface energy.

Valence Electron Theoretical Analysis of Mechanical Properties in Low-Alloy Steel

2011 ◽  
Vol 704-705 ◽  
pp. 389-394
Author(s):  
Chuan Sun ◽  
Yun Kai Li ◽  
Lin Jiang
Keyword(s):  
Mechanical Properties ◽  
Alloy Steel ◽  
Valence Electron ◽  
Electron Structure ◽  
Structure Parameters ◽  
Low Alloy Steel ◽  
Valence Electron Structure ◽  
Empirical Electron Theory ◽  
Valence Electrons ◽  
Set Up

The mechanical properties in low-alloy steel are studied systematically from the view of valence electrons using the Empirical Electron Theory in solid and molecules (EET). Two new valence electron structure parameters ρcvand ρlv, which have closely relation with the mechanical properties of alloy steel are summed up according to the basic idea of EET. The values of the two new valence electron structure parameters in carbon steel and alloy steel which contains Cr, Mn, Ni, Si, W and Mo are calculated. The result demonstrates that ρcvhas a very good corresponding relationship with intensity, and ρlvhas a very good corresponding relationship with plasticity. In this note, a quantitative empirical formula between the valence electrons structure and the intensity and plasticity of alloy steel is initially set up. Keywords: EET, valence electron structure, mechanical property, low-alloy steel

Sign in / Sign up

Export Citation Format

Share Document