Characterization investigations of the mechanically alloyed and sequentially milled Al-12.6 wt.% Si eutectic alloy powders


Tekoğlu E. , Ağaoğulları D. , Ovecoglu M. L.

PARTICULATE SCIENCE AND TECHNOLOGY, vol.38, no.1, pp.15-22, 2020 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 38 Issue: 1
  • Publication Date: 2020
  • Doi Number: 10.1080/02726351.2018.1481899
  • Title of Journal : PARTICULATE SCIENCE AND TECHNOLOGY
  • Page Numbers: pp.15-22

Abstract

This study reports on the detailed microstructural characterization of Al-12.6 wt.% Si eutectic alloy powders synthesized from Al and Si elemental starting materials via mechanical alloying (MA) for 4, 6, and 8 h, and subsequent cryomilling (CM). Mechanically alloyed (MA'd) powders were cryomilled (CM'd) for 10, 20, and 30 min in a freezer/mill using liquid N-2 gas circulated externally around the polycarbonate milling vial containing stainless steel rods. SEM/EDS and TEM/EDS mapping analyses revealed the presence of some Si embedded in the Al-rich particles and some existed as free Si. As expected, with increasing MA and sequential milling (MA + CM) duration, strain values increased and crystallite sizes decreased. Si solubility in alpha-Al was enhanced with increasing MA durations and utilizing MA and CM consecutively (sequential milling) as indicated by DSC endothermic and XRD peak shifts. A maximum solubility of 2.25 at.% Si in alpha-Al or Si solid solubility extension of 0.65 at.% was estimated for the Al12.6Si eutectic alloy powders MA'd for 8 h.