Effect of Annealing on Microstructure and Microhardness of Co-Fe-Ni-Ta-B-Si Bulk Metallic Glass

Hitit A., Geçgin M., Öztürk P.

Journal of Materials Science and Technology, vol.31, no.2, pp.148-152, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 31 Issue: 2
  • Publication Date: 2015
  • Doi Number: 10.1016/j.jmst.2014.09.004
  • Journal Name: Journal of Materials Science and Technology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.148-152
  • Keywords: Metallic glass, Annealing, Microhardness, SOFT-MAGNETIC PROPERTIES, THERMAL-STABILITY, CRYSTALLIZATION BEHAVIOR, VICKERS HARDNESS, FORMING ABILITY, ALLOYS, STRENGTH, KINETICS, MPA
  • Anadolu University Affiliated: Yes

Abstract

© 2014.Effects of annealing temperature and time on microstructure and microhardness of Co41Ni2Fe20Ta5.5B26.5Si5 amorphous alloy have been investigated. Microhardness of the as-cast alloy is found to be 1170HV. The maximum microhardness,1798HV, is achieved after annealing the amorphous alloy at 1250K for 10min. Examination of the microstructure reveals that (Co,Fe)2B, (Co,Fe)21Ta2B6 and (Co,Fe)16Ta6Si7 phases precipitate in the matrix after annealing. Intrinsic hardness and Hall-Petch coefficients of the precipitates indicate that high hardness values result from precipitation of (Co,Fe)2B and (Co,Fe)21Ta2B6 phases. It is also observed that increasing the annealing time results in the decrease in microhardness values because of the increase in particle sizes of the precipitates.