Ablation behavior of La2O3 modified C/C–ZrC composites fabricated by precursor infiltration and pyrolysis

Abstract

La2O3 modified C/C–ZrC composites were produced by precursor infiltration and pyrolysis (PIP) technique, and the ablation resistance was tested in plasma flame at 1700 and 2400 °C. Results displayed that the density of the composites was ∼1.90 g/cm3, and ZrC and La2O3 were uniformly distributed in them. At 2400 °C, the linear and mass ablation rates of La2O3 modified C/C–ZrC composites were 8.89 ± 0.82 μm/s and 0.21 ± 0.01 mg/s, respectively. The positive effect of La2O3 was to promote the liquid phase sintering of ZrO2, which was helpful to promote the formation of an inlaid La–Zr–O molten layer that acted as a protective barrier. At 1700 °C, the composites exhibited minimal linear and mass ablation rates of 0.41 ± 0.14 μm/s and 0.04 ± 0.01 mg/s, respectively. At this temperature, La2O3 promoted the solid phase sintering of ZrO2 to form an intact La–Zr–O particle-stacked layer, and the intact oxide layer positively protected the composites.