Ablation behavior of ZrB2–SiC ceramics modified by low-temperature synthesized Ta4HfC5

The introduction of transition metal carbides has been shown to improve the oxidation resistance of ZrB 2 -SiC ceramics at moderate temperatures; however, their effectiveness under ultra-high temperature ablation conditions remains limited. In this work, nanoscale Ta 4 HfC 5 powder was synthesized at a low temperature (1400 °C) via a three-dimensional gel network, which enables ZrB 2 -SiC-Ta 4 HfC 5 ceramic to achieve high densification below 2000 °C. Oxyacetylene ablation tests at surface temperatures above 2100 °C demonstrated that the incorporation of Ta 4 HfC 5 significantly improved the ablation resistance, resulting in a dense and adherent oxide layer with a negative linear ablation rate. The improved ablation behavior was associated with the formation of multicomponent oxides during high-temperature oxidation, which contributed to the stabilization of the oxide scale. This study highlights the potential of Ta 4 HfC 5 as an effective functional additive for ZrB 2 –SiC-based ultra-high temperature ceramics.