Oxidation and crystallization of Zr-based bulk metallic glass due to machining


Bakkal M. , LIU C., WATKINS T., SCATTERGOOD R., SHIH A.

INTERMETALLICS, vol.12, no.2, pp.195-204, 2004 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 12 Issue: 2
  • Publication Date: 2004
  • Doi Number: 10.1016/j.intermet.2003.09.017
  • Title of Journal : INTERMETALLICS
  • Page Numbers: pp.195-204
  • Keywords: metallic glasses, oxidation, machining, X-ray diffraction, scanning, NANOCRYSTALLINE COMPOSITES, MECHANICAL-PROPERTIES, FRACTURE

Abstract

Bulk metallic glass was subjected to extreme deformation conditions during machining operation. The flash temperature, oxidation and crystallization within chips from a Zr-based bulk metallic glass were investigated. A near-infrared spectrometer was used to capture the light emission from the tool-chip interface allowing the calculation of the temperature. Very high temperatures in the 2400-2700 K range were observed and associated with the light emission and oxidation in the chips. X-ray diffraction analysis revealed oxidation of chips machined at high cutting speeds. Optical micrographs of polished and etched chip cross-sections showed a dendritic pattern due to crystallization. Using a field emission gun SEM, amorphous and crystalline regions were analyzed. This study demonstrates the oxidation and crystallization of bulk metallic glass during machining. (C) 2003 Elsevier Ltd. All rights reserved.