Study on the anti-ablation behavior of (Ti,W)3AlC2 under oxyacetylene flame above 2500 K

Abstract

To evaluate the reliability of (Ti,W)3AlC2 in aerospace ablation conditions, the ablation behavior of (Ti,W)3AlC2 ceramic is investigated by using oxyacetylene flame above 2550 K. Results show a four-stage process exists with the formation of TiO2-Al2TiO5-Al2O3. Once the central ablation temperature exceeds 2350 K, the innermost Al2O3 layer melts and collapses, exposing the decomposed TiCx-Al matrix directly to the flame with rapid oxidation and a remarkable increase of the linear ablation rate. The melt finally flows out with the flame from the ablation center and solidifies into a stripe-like TiO2-Al2TiO5 eutectic oxide above the protective oxide layer. The refractory W particles detected in the eutectic TiO2-Al2TiO5 may retard the flowing rate of the fluid by increasing its viscosity, resulting in a better ablation resistance performance in the later period of the ablation process, making the linear ablation rate lower from 10.30 μm/s of Ti3AlC2 to 9.01 μm/s of (Ti,W)3AlC2.