Title page for etd-0713104-224818


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URN etd-0713104-224818
Author Tzu-Hsiang Hung
Author's Email Address No Public.
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Department Materials Science and Engineering
Year 2003
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Study of Thermal Properties in Zr-Al-Cu-Ni Amorphous Alloy by Adding Boron and Silicon
Date of Defense 2004-06-30
Page Count 102
Keyword
  • metallic glass
  • amorphous alloys
  • crystallized kinetics
  • supercooled liquid
  • Abstract It has been reported that the Zr-based amorphous alloys exhibit high corrosion resistance, good mechanical properties, better thermal stability and good glass-forming ability. The thermal properties of the Zr-Al-Cu-Ni amorphous alloys could be improved by adding boron and silicon that also has been reported. Therefore, the Zr-Al-Cu-Ni amorphous alloys are chosen as the base materials for investigating the effect of the thermal properties by adding boron and silicon at the same time.
     According to the results of the experiment, the Zr60Al7.5Cu17.5Ni10B1Si4 amorphous alloy ribbons with the highest GFA index (g value) and the value is 0.42; the maximum supercooled liquid region (DTx) is about 85 K for the Zr60Al7.5Cu17.5Ni10B1Si4 amorphous alloy ribbons. For the isothermal analysis or non-isothermal analysis, the Avrami index (n value) is not constant, and the Zr60Al7.5Cu17.5Ni10B1Si4 amorphous alloy ribbons with the largest activation energy which was more than 300 kJ/mol. When the Zr60Al7.5Cu17.5Ni10B1Si4 amorphous alloy ribbons were heated to 721 K and held for 4000 seconds, the crystallized phases were ZrO2 with orthorhombic structure and Zr2Ni with tetragonal structure. When the Zr62Al7.5Cu17.5Ni10B2Si1 amorphous alloy ribbons were heated to 724 K and held for 4000 seconds, besides the ZrO2 phase with orthorhombic structure and the Zr2Ni phase with tetragonal structure, a Zr2Ni crystallized phase with cubic structure is also included. According to the observation of the TEM image for heating Zr62Al7.5Cu17.5Ni10B2Si1 amorphous alloy ribbons to 694 K and held for 4000 seconds, there are many grains distribute in the amorphous matrix, and the grain size is about 20 ~40 nm.
    Advisory Committee
  • New-Jin Ho - chair
  • Jason Shian-Ching Jang - co-chair
  • J. Chih-Ching Huang - advisor
  • Files
  • etd-0713104-224818.pdf
  • indicate accessible in a year
    Date of Submission 2004-07-13

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