TY - JOUR
T1 - Optimized processing of high density ternary hafnium-tantalum carbides via field assisted sintering technology for transition into hypersonic applications
AU - Wolfe, Douglas E.
AU - Albert, Patrick E.
AU - Ryan, Caillin J.
AU - Reiss, Justin A.
AU - Stepanoff, Sergei P.
AU - Kolonin, Petr A.
N1 - Funding Information:
We would like to gratefully acknowledge the internal development funding from The Applied Research Laboratory at The Pennsylvania State University for their financial support of this work.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/2
Y1 - 2022/2
N2 - Ultra-high temperature ceramics (UHTCs) present great opportunities for hypersonic applications, but densification via conventional sintering is challenging and often requires sintering aids, limiting UHT applications. Field-assisted sintering technology (FAST) can produce dense, mechanically-robust components without the need for sintering aids. In this work, we have developed an optimized set of FAST processing conditions without sintering aids for various compositions in the (Hf,Ta)C ternary system. The novel processing approach yields high-density ceramics with minimal grain growth. It was found that 50 vol% HfC (∼55 mol%) demonstrated record-breaking nanohardness (41.45 ± 1.37 GPa), Vickers microhardness (30.2 ± 3.1 GPa), and elastic (indentation) modulus (590.12 ± 10.64 GPa). These peak mechanical properties arose from the balance of two underling structure-property relationships: solid solution strengthening and the Hall-Petch effect. The interplay of these compositionally-linked phenomena yields an optimal regime of superior mechanical properties. Combining this interplay with optimized FAST parameters, superior ternary HfC-TaC ceramics can be realized for next-generation hypersonic applications.
AB - Ultra-high temperature ceramics (UHTCs) present great opportunities for hypersonic applications, but densification via conventional sintering is challenging and often requires sintering aids, limiting UHT applications. Field-assisted sintering technology (FAST) can produce dense, mechanically-robust components without the need for sintering aids. In this work, we have developed an optimized set of FAST processing conditions without sintering aids for various compositions in the (Hf,Ta)C ternary system. The novel processing approach yields high-density ceramics with minimal grain growth. It was found that 50 vol% HfC (∼55 mol%) demonstrated record-breaking nanohardness (41.45 ± 1.37 GPa), Vickers microhardness (30.2 ± 3.1 GPa), and elastic (indentation) modulus (590.12 ± 10.64 GPa). These peak mechanical properties arose from the balance of two underling structure-property relationships: solid solution strengthening and the Hall-Petch effect. The interplay of these compositionally-linked phenomena yields an optimal regime of superior mechanical properties. Combining this interplay with optimized FAST parameters, superior ternary HfC-TaC ceramics can be realized for next-generation hypersonic applications.
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U2 - 10.1016/j.jeurceramsoc.2021.10.014
DO - 10.1016/j.jeurceramsoc.2021.10.014
M3 - Article
AN - SCOPUS:85117694522
SN - 0955-2219
VL - 42
SP - 327
EP - 335
JO - Journal of the European Ceramic Society
JF - Journal of the European Ceramic Society
IS - 2
ER -
