Oxidation resistance and emissivity of diboride-based composites containing tantalum disilicide in air plasma up to 2600 K for space applications

Radiation heat transfer during hypersonic flight: A review of emissivity measurement and enhancement approaches of ultra‐high temperature ceramics

“…The authors reported that TaSi 2 provided sufficient protection against oxidation upto ∼1900°C, which is 200°C beyond the capability of SiC. This improved oxidation inhibition was caused by the formation of a stable ZrO 2 ‐Ta 2 O 3 or HfO 2 ‐Ta 2 O 3 microstructure as proposed by the authors 53 . The total normal emittance values of pre‐oxidized HfB 2 ‐20 vol% TaSi 2 and ZrB 2 ‐20 vol% TaSi 2 were measured to be ϵ ┴ = 0.90 and ϵ ┴ = 0.80, respectively.…”

“…This improved oxidation inhibition was caused by the formation of a stable ZrO 2 -Ta 2 O 3 or HfO 2 -Ta 2 O 3 microstructure as proposed by the authors. 53 The total normal emittance values of pre-oxidized HfB 2 -20 vol% TaSi 2 and ZrB 2 -20 vol% TaSi 2 were measured to be ϵ ┴ = 0.90 and ϵ ┴ = 0.80, respectively. The authors 53 did not provide a reason for the observed high emittance values.…”

“…53 The total normal emittance values of pre-oxidized HfB 2 -20 vol% TaSi 2 and ZrB 2 -20 vol% TaSi 2 were measured to be ϵ ┴ = 0.90 and ϵ ┴ = 0.80, respectively. The authors 53 did not provide a reason for the observed high emittance values. However, the increased rate of TaSi 2 vaporization at elevated temperatures over ∼1727 • C made TaSi 2 -reinforced diboride composites impractical for hypersonic reentry applications.…”

“…In an attempt to improve the oxidation resistance of diboride‐based UHTCs, Pellegrini et al 53 . replaced SiC with TaSi 2 when sintering ZrB 2 , and HfB 2 .…”

“…In an attempt to improve the oxidation resistance of diboride-based UHTCs, Pellegrini et al 53 replaced SiC with TaSi 2 when sintering ZrB 2 , and HfB 2 . The authors reported that TaSi 2 provided sufficient protection against oxidation upto ∼1900 • C, which is 200 • C beyond the capability of SiC.…”