EELS analysis of the matrix, quasi-crystalline and crystralline phases in aged Zr46.7 Ti8.3 Cu7.5 Ni10 Be27.5 bulk glasses
B. Van De Moortele 1, Thierry EPICIER 1, J.M. Pelletier 1 and J.L. Soubeyroux 2
e-mail: Thierry.Epicier@insa-lyon.fr
1 GEMPPM, umr CNRS 5510, INSA de Lyon, F-69621 Villeurbanne Cedex
2 CRETA, CNRS, 25 avenue des martyrs, BP 166, F-38042 Grenoble Cedex 09
Bulk metallic glasses, frequently based on multi-components Zr-alloys, represent a new class of materials with potential applications, owing to their excellent processing capabilities.
Among these glasses, the ZrTiCuNiBe family is of particular interest. When subjected to long time heat treatment (typically a few hours) at 380°C (about 35°C above Tg - glass transition temperature -), these compounds undergo nano-crystallization, with an intermediate apparition of quasi-crystalline phases.
Although an abundant literature exists on these materials [1], there is few if any detailed chemical information regarding the elemental composition of the quasi-crystalline and crystalline phases formed during ageing. It is then the purpose of this work to report such data on the Zr46.7 Ti8.3 Cu7.5 Ni10 Be27.5 (so-called V4) bulk glass.
The simultaneous presence of metallic (heavy) elements and a light atomic specie (i.e. Be) makes it necessary to use a combination of EDX and EELS spectroscopies in the TEM. Further, owing to the nanometric size of the precipitates, nano-probe analysis has to be carried out.
The results, obtained on a JEOL 2010F instrument equipped with an OXFORD EDX analyzer and a GATAN DigiPeels, highlight the proeminant role of Be in the structural evolution of the matrix after annealing.
[1]W.L. JOHNSON, MRS Bull., 24, (1999), 42 (and references within).