Abstract
Zr65Ni10Cu7.5Al7.5Ag10bulk metallic glass was prepared by copper-mould casting. The kinetics and structure related to the phase transformation of the bulk metallic glass were studied by X-ray diffraction, differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). It was found that the Zr65Ni10Cu7.5Al7.5Ag10bulk metallic glass exhibits a distinct glass transition followed by two exothermic reactions, with the first reaction being the amorphous-to-quasicrystalline transformation, and the second being the quasicrystalline-to-Zr2Cu intermetallic transformation. The isothermal kinetics for amorphous-to- quasicrystalline transformation was quantitatively analyzed in the framework of JMA equation. The parameter of local Avrami exponent was introduced to explain the details of nucleation and growth behaviour in the transformation. It was revealed that the local Avrami exponent for the transformation varied with an increase in the volume fraction transformed, indicating that multi-mechanisms were involved in the transformation. TEM observations demonstrated that the variation in transformation kinetics at different stages is most likely the result of the structural inhomogeneity in the as-cast bulk metallic glass caused by a temperature gradient along the radius direction during casting.
| Original language | English |
|---|---|
| Pages (from-to) | 1143-1148 |
| Number of pages | 6 |
| Journal | Intermetallics |
| Volume | 12 |
| Issue number | 10-11 SPEC. ISS. |
| DOIs | |
| Publication status | Published - 1 Oct 2004 |
Keywords
- B. Glasses, metallic
- D. Microstructure
ASJC Scopus subject areas
- General Chemistry
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry