Mechanical properties of hafnium tantalum carbides via field assisted sintering technology for hypersonic vehicles

Patrick E. Albert, Caillin J. Ryan, Erik T. Furton, Ryan Sweny, Michael P. Galaini, Ryan J. Crealese, Petr A. Kolonin, Allison M. Beese, Douglas E. Wolfe

Research output: Contribution to journalArticlepeer-review


Ultra-high temperature ceramics (UHTCs) are refractory transition-metal carbides, nitrides, and borides with the highest melting temperatures known materials, making them prime candidates for applications in aerospace and hypersonic vehicles. Of the UHTCs, tantalum carbide (TaC) and hafnium carbide (HfC) feature the highest melting temperatures. We investigated the binderless consolidation of HfC/TaC powder blends using Field Assisted Sintering Technology (FAST). Powders consisting of 90/10, 50/50, and 10/90 vol% HfC:TaC were sintered to high densities (>94 %). Bulk and nanomechanical, chemical, and microstructural characterization revealed substantially greater strength, hardness, and stiffness for ternary alloys. Mechanical properties correlated with physiochemical analysis indicated trace oxygen phases, solid-solution strengthening, and nonstoichiometric carbon were the key mechanisms driving the peak property enhancement of the 50 vol% solid-solution sample, despite lower densities. This study provides insight into optimizing the compositional design of HfC-TaC alloys by balancing influences from solid solution strengthening and the thermodynamic effects of oxygen/carbon stoichiometry.

Original languageEnglish (US)
Pages (from-to)6827-6838
Number of pages12
JournalJournal of the European Ceramic Society
Issue number12
StatePublished - Sep 2024

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • Materials Chemistry

Cite this