Glass transition Tg, and quenched-in free volume in bulk metallic glasses measured by X-ray diffraction

A. R. Yavari, A. Le Moulec, N. Nishiyama, A. Inoue, G. Vaughan, A. Kvick, W. J.F. Botta

Research output: Contribution to journalConference articlepeer-review

2 Citations (Scopus)

Abstract

In this work we show that through thermal expansion am measured by real-time diffraction using synchrotron light in transmission, the "glass transition Tg" and for the first time, the "quenched-in free volume" can be quantitatively measured in bulk metallic glasses. This was impossible previously as metallic glasses with crystallisation temperature Tx near Tg crystallized during real-time diffraction experiments. This limitation does not hold for newly developed bulk metallic glasses (BMGs) with large supercooled regions ΔT = Tx-T g. Under such conditions, the variation, Δαth, of the volume coefficient of thermal expansion has been measured by diffraction near Tg for a number of bulk metallic glasses. A clear Δαth has been detected in the same glass transition temperature range of ΔCp measured by DSC calorimetry in particular for Pd-based, Zr-based and Hf-based bulk glasses. The directly measured quenched-in free-volume content Vf is reported here for the first time is found, as expected, to depend on the quench rate and anneals out just below Tg.

Original languageEnglish
Pages (from-to)23-28
Number of pages6
JournalJournal of Metastable and Nanocrystalline Materials
Volume20-21
DOIs
Publication statusPublished - 2004 Jan 1
EventProceedings of the 10th International Symposium on Metastable Mechanically Alloyed and Nanocrystalline Materials (ISMANAM-2002) - Foz do Ifuacu, Brazil
Duration: 2003 Aug 242003 Aug 28

Keywords

  • Bulk Metallic Glasses
  • Free Volume
  • Glass Transition Temperature
  • Synchrotron Radiation

ASJC Scopus subject areas

  • Materials Science (miscellaneous)
  • Materials Science(all)
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Glass transition T<sub>g</sub>, and quenched-in free volume in bulk metallic glasses measured by X-ray diffraction'. Together they form a unique fingerprint.

Cite this