Thermal stability, dynamic mechanical analysis and nanoindentation behavior of FeSiB(Cu) amorphous alloys

H. R. Lashgari, Z. Chen, X. Z. Liao, D. Chu, M. Ferry, S. Li

Research output: Journal article publicationJournal articleAcademic researchpeer-review

32 Citations (Scopus)

Abstract

The aim of the present study is to investigate the crystallization behavior, microstructural evolution and mechanical behavior of the Fe-based amorphous alloy with three various compositions (at%): Fe80.75Si8B11.25 (Cu-free and Silicon-rich alloys), Fe85.2Si0.9B12.62Cu1.28 and Fe78.6Si1.8B17.75Cu1.85 (Cu-containing and Si-poor alloys). The presence of Cu decreased the activation energy of the first crystallization peak and glass transition temperature. Furthermore, anomalous behavior was observed in Avrami exponent at the final stage of the crystallization of the Cu-containing alloys. Absence of Cu resulted in a coarse dendritic structure while finer and equiaxed grains were achieved by Cu addition. Nanoindentation size effect (the decrease of hardness with the increase of indentation depth) was observed in amorphous ribbons (regardless of composition) from 10 to 70mN load and further increase of load did not change the hardness and Young[U+05F3]s modulus noticeably. Isothermal annealing effectively increased the hardness (H) and Young[U+05F3]s modulus (Er) of the alloys. In addition, it was found that the plastic work of nanoindentation decreased after annealing in Cu-free alloy whereas it increased in Cu-containing one which could be due to the refined microstructure. Besides, shear bands around the indents in amorphous ribbons were disappeared after 1h annealing which could be due to the change in plastic deformation mechanism from shear banding to strain-hardening.

Original languageEnglish
Pages (from-to)480-499
Number of pages20
JournalMaterials Science and Engineering A
Volume626
DOIs
Publication statusPublished - 5 Feb 2015
Externally publishedYes

Keywords

  • DMA
  • FeSiBCu amorphous alloy
  • Microstructure features
  • Nanohardness
  • Thermal stability

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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