STUDY ON THE RELATIONSHIP BETWEEN VALENCE ELECTRON STRUCTURE AND COATING ORIENTED GROWTH

2015 ◽  
Vol 22 (03) ◽  
pp. 1550039
Author(s):  
SHUYONG TAN ◽  
XUHAI ZHANG ◽  
RUI ZHEN ◽  
LEI ZHANG ◽  
ZENG TIAN ◽  
...  
Keyword(s):  
Electron Density ◽  
Valence Electron ◽  
Preferred Orientation ◽  
Density Difference ◽  
Crystal Face ◽  
Oriented Growth ◽  
Valence Electron Structure ◽  
Electron Density Difference ◽  
Fine Grain ◽  
Calculation Results

The coating oriented growth has attracted great attention because of its effect on coating properties. In this paper, the valence electron structures of TiN and Ni were calculated with the empirical electron theory (EET) in solid and molecules for investigating preferred orientation of nitride coatings containing Ni . The calculation results show that Ni (111), CrN (100) and TiN (100) are the maximum crystal-face electron density, respectively. In CrN (or TiN ) coatings, if Ni does not form a single nickel phase, CrN (100) (or TiN (100)) preferred orientation appears easily due to its high crystal-face electron density. When Ni exists as a single phase, CrN (100)/ Ni (111) (or TiN (100)/ Ni (111)) with the minimum crystal-face electron density difference is the most likely to appear in the coatings. Furthermore, high crystal-face electron density difference usually implies fine grain microstructure. The calculation results are consistent with the experimental results.

VALENCE ELECTRON STRUCTURE ANALYSIS OF INTERFACE OF FeAl/TiN COMPOSITES

2007 ◽  
Vol 14 (01) ◽  
pp. 17-21 ◽  
Author(s):  
L. X. PANG ◽  
K. N. SUN ◽  
S. REN ◽  
J. Q. BI ◽  
R. H. FAN
Keyword(s):  
Mechanical Properties ◽  
Electron Density ◽  
Valence Electron ◽  
Valence Electron Structure ◽  
Electron Density Difference ◽  
Relative Electron Density ◽  
Relative Electron ◽  
Nature Of Chemical Bond ◽  
Set Up ◽  
Properties Of Composites

Based on Pauling's nature of chemical bond, the valence electron structures of TiN and FeAl have been constructed, and the relative electron density differences (REDD) between the low index plane of TiN and FeAl , respectively, have been calculated. [110] FeAl //[110] TiN crystallography orientation has been set up from the minimization of the electron density difference across the interface. From the viewpoint of improving the mechanical properties of composites, the formation of such structures must been engineered in the fabrication processing.

INTERFACE ELECTRON STRUCTURE OFTiC–NiAlCOMPOSITES

2012 ◽  
Vol 19 (05) ◽  
pp. 1250056
Author(s):  
X.-F. TIAN ◽  
W.-K. ZHANG ◽  
Y. QI
Keyword(s):  
Electron Density ◽  
Valence Electron ◽  
Electron Structure ◽  
Matrix Composites ◽  
Communication Interface ◽  
Valence Electron Structure ◽  
Valence Electron Density ◽  
Intermetallic Matrix ◽  
Intermetallic Matrix Composites ◽  
Set Up

Intermetallic matrix composites reinforced with ceramic particles such as TiC have received increasing attention in recent years due to the combined potential of ceramics and intermetallics to give a desirable balance of properties. But an understanding of some experimental results presented elsewhere has remained elusive. In this communication, interface valence electron structure of TiC–NiAl composites was set up on the basis of Pauling's nature of the chemical bond, and valence electron density ρ of different atomic states TiC and NiAl composites in various planes was determined. From the viewpoint of biphase interface electron density continuing, the corresponding experimental phenomena are explained.

Study on the Precipitated Behavior and Stability of the Strengthening Phase Al12(Fe,X)3Si in Al-Fe-Si-X Alloys with the EET Theory

2010 ◽  
Vol 152-153 ◽  
pp. 743-747
Author(s):  
Hua Qu ◽  
Wei Dong Liu ◽  
Gang Zhou ◽  
Xiao Lu Shen ◽  
Chuang Liu
Keyword(s):  
Valence Electron ◽  
Electron Structure ◽  
Alloying Elements ◽  
Strengthening Phase ◽  
Alloying Element ◽  
Valence Electron Structure ◽  
Empirical Electron Theory ◽  
Calculation Results ◽  
The Stability ◽  
State Group

According to the empirical electron theory of solid and molecule, the effects of alloying elements on the valence electron structure, precipitated behavior and stability of Al12Fe3Si were studied in this paper. The calculation results show that the adding of V, Cr, W, Mo and Mn change the valence electron structure of Al12Fe3Si, and make its number of atom state group N increased by 2 orders of magnitude, so it make the stability of the alloy increased and then delay the coarsening speed; the adding of alloying element makes the total ability of forming bond F reduced and accelerates the precipitated of Al12Fe3Si and make it refined; the order for the adding of the alloying elements V, Cr, W, Mo and Mn of the effects on stability of Al12Fe3Si is Cr(Mn)→W(Mo)→V, and that of accelerating the dispersion precipitated of Al12Fe3Si is Cr→V→Mo→W→Mn; when practicing to design Al-Fe-Si-X alloy, we can obtain it through controlling the ratio of Fe/X to refine the particles of Al12(Fe,X)3Si, therefore, its stability can be improved and its coarsening can be delayed.

The Performance Research of Different Concentrations of Methyl Adsorption on Si (110) Surface

2014 ◽  
Vol 988 ◽  
pp. 121-124
Author(s):  
Zheng Xin Yan ◽  
Dong Zhi Yan ◽  
Qian Chen ◽  
An Gong ◽  
Qian Liao
Keyword(s):  
Electron Density ◽  
Adsorption Energy ◽  
First Principles ◽  
Structure Change ◽  
Density Difference ◽  
Energy Increase ◽  
Adsorption Models ◽  
Electron Density Difference ◽  
Adsorption Structure ◽  
Performance Research

First-principles method was carried out to investigate the methyl chemical adsorbing on Si (110) surface. To clarify the different concentrations of methyl on Si (110) surface, the mono-methyl, double-methyl, treble-methyl, and quadruple-methyl on the Si surface adsorption models were comparably investigated. Adsorption energy and methyl C-H bond structure change, density of states and electron density difference were used to analyze the structure change of adsorption models. The adsorption energy shows that Si surface top site has significant sensitivity to methyl, and the adsorption energy increase with the increasing methyl concentrations. The electron density difference data show charge transfer is obvious and electron cloud center tend to Si atom with Si-C bond formed. The PDOS of methyl reveals electron peaks move to the low direction about (5.5036, 5.7868, 5.8572, 5.8788eV) with the increasing concentrations of methyl. The data above exhibit that quadruple-methyl adsorption structure is more stable one. The conclusion can provide the insight for gas detection and sensors.

The Chemisorptions Mechanism Study of Methyl on Different Bonds in Porous Silicon

2013 ◽  
Vol 864-867 ◽  
pp. 399-403
Author(s):  
Dong Zhi Yan ◽  
Zheng Xin Yan ◽  
Tao Zhang ◽  
Hua Ping Yang ◽  
An Gong ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Charge Transfer ◽  
Electron Density ◽  
Low Energy ◽  
Density Difference ◽  
Density Of State ◽  
Mechanism Study ◽  
Electron Density Difference ◽  
Strength Difference ◽  
Model Structures

The absorbing kinetic process of methyl on Si (111) surface was comprehensively studied using the method of quantum mechanics. We optimized the model structures of radical CH3+, Si (111), and CH3+ on Si (111) to obtain a rational convergence for the present calculations. The electron density difference and density of states of each model were calculated by CASTEP. The electron density difference of CH3+ on Si (111) reveals that the charge transfer factor is difference for different absorption positions, which indicates that the bond strength difference. The density of state of model exhibits that the electronic peaks move to the low energy direction. However, the absorption on B (-8.57, -2.19, 0.91) position shows a higher electron shift which evidences that it is the appreciating absorption position.

Rechnerische Simulation eines ein-dimensionalen Fehlordnungsmodells für K0,5V2O5

1999 ◽  
Vol 214 (2) ◽  
Author(s):  
H. Katzke ◽  
K. Kato
Keyword(s):  
Electron Density ◽  
Computer Simulations ◽  
Volume Ratio ◽  
Density Difference ◽  
Electron Density Difference ◽  
One Dimensional ◽  
Difference Map

AbstractA one-dimensional disorder model has been proposed for the structure of the so-calledComputer simulations showed, that the structure published by these authors can be explained by a model in which the layer sequences of the orthorhombic and the monoclinic structures randomly appear in a volume ratio of about 7 to 3. The trigonal-prismatically six-fold coordinated K position has been revealed to be a false maximum in the electron-density difference map. The orthorhombic (

Calculation of Statistical Values of Phase Interface Valence Electron Structure Parameters of Cu-Zn Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 147-150
Author(s):  
Fei Li ◽  
Xia Zhao
Keyword(s):  
Valence Electron ◽  
Phase Interface ◽  
Weight Percent ◽  
Electron Structure ◽  
Interface Bonding ◽  
Valence Electron Structure ◽  
Calculation Results ◽  
The Stability ◽  
Zn Alloy ◽  
Average Atom Model

Based on the average atom model, the statistical values of valence electron structure (VES) parameters Δρ′, σ of homophase interface and heterpphase interface had been calculated in Cu-Zn alloy. VES parameters can characterize properties of interface bonding. The effect of Zn in the Cu matrix on the interface strengthening was discussed by the Δρ′ and σ. The calculation results showed that Δρ′ and σ values of homophase interface and heterophase interface of alloy phase were bigger than ones of Cu matrix. It was the essence of interface strenghening. The heterophase interface value σ was smaller compared with the homophase interface value σ under different Zn contents (weight percent). It was the reason that the stability of matrix was superior to that of between matrix and solid solution.

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