Ablation behavior of ZrB₂-SiC sharp leading edges

The ablation behavior of ZrB₂-SiC sharp leading edges with different radius (R) values of 0.15 (R1), 0.5 (R2), 1.0 (R3) and 1.5 mm (R4) was investigated using an oxy-acetylene torch. Under the same ablation condition, sharp leading edge with a lower R value underwent a severer ablation. The surface temperature reached a maximum of ∼2100 C for R1, ∼2040 C for R2, ∼2000 C for R3 and ∼1930 C for R4, respectively, and subsequently decreased to a state value of about 1910-1935 C for all models. R1 and R2 underwent intensive mass loss and linear shrinkage, whereas R3 had only a slight mass loss and linear shrinkage, and R4 had a slight mass gain and linear expansion. The finite element analysis (FEA) also gave the simulated temperature distributions in the ZrB₂-SiC sharp leading edge models, which were in good accordance with the experimental results. Considering the surface temperature, shape retention behavior and the lift to drag ratio, R3 (1.0 mm) was therefore selected as the optimal radius value for ZrB₂-SiC sharp leading edge. The microstructures of the cross-section and oxidation surface of R3 were also investigated.