Details

Autor(en) / Beteiligte

• Johnson, Jonathan A.
• Wilkerson, Ryan P.
• Williams, Jamelle K.P.
• Thompson, Gregory B.

Titel

Grain Size Control by Matrix Phase Additives in Nuclear Thermal Propulsion Cermets

Ist Teil von

• Journal of nuclear materials, 2023-04, Vol.577, p.154306, Article 154306

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Refined grain sizes in the metallic phase of a cermet nuclear fuel have been reported to provide improved performance and survivability of the fuel in nuclear thermal propulsion (NTP) applications. In this paper, we study the use of ZrC nanoparticles, which have a low neutron absorption cross-section, as Zener pinning sites for the tungsten matrix in a surrogate fuel - yttria stabilized zirconia (YSZ) – cermet. While the ZrC additions were found to successfully pin grain boundaries, subsequent high temperature hydrogen exposure at 2500 K for 1 hour resulted in significantly more catastrophic cracking in comparison to control specimens with no ZrC additions. This increase in cracking is explained by two gas formation mechanisms - hydrogen recombination at defect sites and water vapor formation from the reduction of YSZ.