Local Structure and Glass Transition in Zr-Based Binary Amorphous Alloys

• Ichitsubo Tetsu

  Department of Materials Science and Engineering, Kyoto University

• Matsubara Eiichiro

  Department of Materials Science and Engineering, Kyoto University

• Saida Junji

  Center for Interdisciplinary Research, Tohoku University

• Chen Ho-Sou

  Bell Laboratories, Lucent Technology

Abstract

The physical significance of the glass transition observed by differential scanning calorimetry (DSC) in the metallic glasses was considered through the measurements of the heating-rate, β, dependence of the glass transition temperature, T_g, and the crystallization temperature, T_x, in the Zr₇₀Cu₃₀ and Zr₇₀Ni₃₀ amorphous alloys and X-ray study of their structures in as-quenched and crystallized states. Zr₇₀Cu₃₀ exhibits the glass transition before crystallization, but Zr₇₀Ni₃₀ is immediately crystallized at heating rates of conventional time scale in the DSC measurement. The heating rate β_c at the intersection of the two linear curves of T_g and T_x against logβ provides us with a significant measure to determine the glass-forming ability or thermal stability of the metallic glasses. By heating at β larger than β_c, the crystallization is suppressed and the glass transition is clearly observed even in Zr₇₀Ni₃₀. The thermal stability of the Zr₇₀Cu₃₀ amorphous alloy is caused by retardation of crystallization due to the amorphous structure that is different from the Zr₂Cu crystalline phase. In contrast, the thermal instability of Zr₇₀Ni₃₀ is attributed to the structural similarity to the Zr₂Ni crystalline phase. Thus, suppressing the crystallization is shown to be a key to enhance the thermal stability of the present amorphous alloys.

Journal

• MATERIALS TRANSACTIONS

  MATERIALS TRANSACTIONS 46 (10), 2282-2286, 2005

  The Japan Institute of Metals and Materials

Keywords

• glass transition
• metallic glasses
• zirconium-based amorphous
• differential scanning calorimetry
• superheating
• X-ray diffraction method
• structual analysis
• supercooled liquid

Details

• CRID: 1390001204250840960
• NII Article ID: 130004452624
• NII Article ID: 10018277924
• NII Book ID: AA1151294X
• DOI: 10.2320/matertrans.46.2282
• ISSN: 13475320
• ISSN: 13459678
• NDL BIB ID: 7488028
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I7488028
• Web Site: https://www.jstage.jst.go.jp/article/matertrans/46/10/46_10_2282/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed