Preparation of high-entropy carbides by different sintering techniques

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Johannes Pötschke - , Fraunhofer Institute for Ceramic Technologies and Systems (Author)
  • Manisha Dahal - , Chair of Inorganic Non-Metallic Materials (Author)
  • Mathias Herrmann - , Fraunhofer Institute for Ceramic Technologies and Systems (Author)
  • Anne Vornberger - , Fraunhofer Institute for Ceramic Technologies and Systems (Author)
  • Björn Matthey - , Fraunhofer Institute for Ceramic Technologies and Systems (Author)
  • Alexander Michaelis - , Chair of Inorganic Non-Metallic Materials, Fraunhofer Institute for Ceramic Technologies and Systems (Author)

Abstract

Dense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.

Details

Original languageEnglish
Pages (from-to)11237-11247
Number of pages11
JournalJournal of materials science
Volume56
Issue number19
Publication statusPublished - Jul 2021
Peer-reviewedYes