Solid state amorphization of metastable Al0.5TiZrPdCuNi high entropy alloy investigated by high voltage electron microscopy

Takeshi Nagase, Akira Takeuchi, Kenji Amiya, Takeshi Egami

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The phase stability of high entropy alloy (HEA), Al0.5TiZrPdCuNi, under fast electron irradiation was studied by in-situ high voltage electron microscopy (HVEM). The initial phase of this alloy quenched from the melt was dependent on cooling rate. At high cooling rates an amorphous phase was obtained, whereas a body-centered cubic (b.c.c.) phase were obtained at low cooling rates. By thermal crystallization of the amorphous phase b.c.c. phase nano-crystals were formed. Upon fast electron irradiation solid state amorphization (SSA) was observed in b.c.c. phase regardless of the initial microstructure (i.e., “coarse crystalline structure” or “nano-crystalline structure with grain boundaries as a sink for point defects”). SSA behavior in the Al0.5TiZrPdCuNi HEAs was investigated by in-situ transmission electron microscopy observations. Because the amorphization is very rarely achieved in a solid solution phase under fast electron irradiation in common metallic materials, this result suggests that the Al0.5TiZrPdCuNi HEA from other common alloys and the other HEAs. The differences in phase stability against the irradiation between the Al0.5TiZrPdCuNi HEA and the other HEAs were discussed. This is the first experimental evidence of SSA in HEAs stimulated by fast electron irradiation.

Original languageEnglish
Pages (from-to)291-300
Number of pages10
JournalMaterials Chemistry and Physics
Volume210
DOIs
Publication statusPublished - 2018 May 1

Keywords

  • High entropy alloys
  • High voltage electron microscopy
  • In situ observation
  • Phase transformation
  • Solid state amorphization

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics

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