Domination of phononic scattering in solid solutioning and interfaces of HfB2–ZrB2 – SiC -carbon nanotube based ultra high temperature composites Article

Dubey, S, S, A, Nisar, A et al. (2022). Domination of phononic scattering in solid solutioning and interfaces of HfB2–ZrB2 – SiC -carbon nanotube based ultra high temperature composites . SCRIPTA MATERIALIA, 218 10.1016/j.scriptamat.2022.114776

cited authors

  • Dubey, S; S, A; Nisar, A; Saini, S; Jana, SS; Wangaskar, B; Das, A; Khandekar, S; Maiti, T; Omar, S; Balani, K

authors

abstract

  • HfB2-ZrB2 based ultra-high temperature ceramics (UHTCs) are used as protective tiles for nose cones and leading edges of the hypersonic vehicles that face harsh service conditions of temperatures >2000 °C. The present work assesses the effect of SiC (20 vol.%) and carbon nanotubes (CNT, 6 vol.%) incorporation on isolating the phononic and electronic contribution to thermal conductivity of spark plasma sintered HfB2-ZrB2 based UHTCs. Except HfB2-SiC, all ZrB2 based UHTC composites elicited similar electrical conductivity (∼ 5.7 × 106 S/m), whereas a marginal increase of ∼9% in thermal conductivity was observed with CNT reinforcement in HfB2-ZrB2–SiC composites. With HfB2/ZrB2-SiC composites eliciting high thermal conductivity (120–150 Wm-1K-1), the current work emphasizes the domination of phononic scattering (by ∼44%) due to solid solutioning in HfB2-ZrB2-based ceramics. Further, electronic thermal scattering events may only be marginal at interfaces of CNT and ZrB2, and limit thermal scattering in HfB2/ZrB2-SiC-CNT based UHTCs for hypersonic applications.

publication date

  • September 1, 2022

published in

Digital Object Identifier (DOI)

volume

  • 218