Dissertation > Excellent graduate degree dissertation topics show

Atomic Bonding and Fractal Structure of Bulk Metallic Glasses

Author: ChenYiQiang
Tutor: ShenJun
School: Harbin Institute of Technology
Course: Materials Processing Engineering
Keywords: Bulk metallic glass Glass-forming ability Raman spectroscopy Renormalization group method Fractal dimension
CLC: TG139.8
Type: Master's thesis
Year: 2011
Downloads: 27
Quote: 0
Read: Download Dissertation

Abstract


Metallic glass has a complex atomic scale microstructure research has always been very challenging hot spots. In this paper, the method of Raman scattering combined with the XPS full name (XPS) testing, the direction of the key characteristics of Ti metallic glass; reveals Ti, Zr, and La-based Raman spectra of the three types of metallic glass, glass forming ability of metallic glass ( GFA) structure of origin; according to the stacking of the program, using the renormalization group method to study the the fractal structural characteristics of the Zr-based metallic glass. In order to study the local bond structure of metallic glasses, the paper selected high GFA Ti 40 the Zr 25 Ni 3 the of Cu 12 Be 20 bulk metallic glass study their behavior. Using XPS proved in the direction of bond formation in the alloy, and the direction key is Be-Ni and Be-Cu key. Raman spectroscopy combined with numerical simulation, and again confirmed that the local bond structure of the alloy, and use the arrow keys to explain the Be Ti metallic glass GFA facts and metallic glass can add enhanced anomalous resistance temperature coefficient (TCR). In order to study the relationship between the Raman spectra of the metallic glass GFA were selected Ti, Zr, and La Raman spectra of the three types of metallic glass, which each type of metal glass select different GFA ingredients. The experiments show that: the major contribution by the three parts, the shear wave acoustic mold (TA), the acoustic mode (LA) of the longitudinal wave vibration mode, and represents a direction key optical mode vibration mode. We found: linear vibration mode overlap is not clearly independent Gaussian function and Lorentz-type function fitting the spectrum. Optical vibration modes and acoustic vibration modes overlap shows local vibration of the atoms can be transformed into a collective vibration through some kind of transformation. Based on the Raman spectra, from the point of view of the collective collaboration vibration and local atomic motion and atomic structure of the relationship between the study of the GFA of bulk metallic glass and Ti-based metallic glass Zr-and La fund, for example, extracted from the Raman spectra out a simple parameter η = ITA / ITO (ITA and ITO respectively TA modulus and TO mode Raman intensity) to characterize the GFA of bulk metallic glass. The GFA and η is almost as simple monotonic decreasing linear relationship, i.e. η lower, GFA The higher. And Zr-based metallic glass, the parameter η characterization GFA brittle coefficient m simple linear relationship also exists between. Taking into account the characteristics of the collective motion in the metallic glass, the collective movement mainly Chinese and the movement of the program. Program in metallic glass stacking fractal characteristics, and fractal is a random fractal. But this is only in the scale of the program, about 5? The 2 0? Between the outside of this scale, it is no longer a random fractal characteristics. By fitting the Zr-based metallic glass catamaran associated distribution function to obtain the Zr-based metallic glass df = 2.475, which is consistent with the results obtained in the first diffraction peak in the X-ray diffraction analysis. Then, build the program in the metallic glass stacking renormalization model to calculate the renormalization of the critical exponents and the fractal dimension. The results show that the arrangement of the program more closely spaced, the smaller the critical index, the greater the fractal dimension.

Related Dissertations

  1. Investigations of Structure and Glass Forming Abilty of Amorphous Alloys,TG139.8
  2. The Experiment of Normal Bond Properties between FRP and Concrete,TU528.572
  3. Layer-by-layer Assembly of Nanoparticles for Surface-enhanced Raman Spectroscopy Substrate and the Application in Detection of Organic Molecules,O657.3
  4. Research Oncognitive Radio Cooperate Spectrum Sensing,TN925
  5. Instrument-to-Instrument Calibration Transfer and Standardization of Spectra,O657.33
  6. High-speed detection and bayonet vehicle license identification information,TP391.41
  7. Based on synchrotron radiation CT imaging of breast cancer quantitative study of microvascular,R318
  8. Ethanol - water Raman spectroscopy and density correlation,O657.37
  9. The Study of Artificial Target Detection Based on Fractal Feature,TP391.41
  10. Research on the Surface Enhanced Raman Spectroscopy of Saliva for the Diagnosis of Lung Cancer,R734.2
  11. The Application of Rockmass Mechanics in Coal Deformation,P618.11
  12. Fractal Characteristics of Protein Molecules,Q51
  13. Study on Laser Raman Spectra of Nude Mice Models with Human Gastric Cancer in Vivo,O433.5
  14. Structure and Magnetic Properties of FeCuNb (Ti) SiB,TG139.8
  15. Glass Forming Ability and Atomic Size Factor of Bulk Amorphous Alloys,TG139.8
  16. AAO template - based SERS substrate research,TB383.1
  17. Fractal-based non- uniform flow of soil Experimental research and numerical simulation,S152
  18. EEG-EMG Synergistic Analysis and Correlation Study Based on External-Source Load Inspiration,R87
  19. The Research of Image Segmentation Based on Fractal and Active Contour Model,TP391.41
  20. Numerical Study of ISA furnace hydraulics model based on CFD and fractal theory multiphase mixing effect,TP391.41
  21. The Study of Blood Vessel and Tissue Injured by Anti-angiogenic Drugs Basing on Raman Spectroscopy,R730.5

CLC: > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > The alloy learn with a variety of properties of alloys > Other special nature of the alloy > Amorphous alloy
© 2012 www.DissertationTopic.Net  Mobile