ZrB2–SiC composite parts in oxyacetylenic torch tests: Experimental and computational assessment of chemical, thermal and mechanical behavior

The thermal shock and ablative behavior of ZrB2–SiC pyramidal mockups with different geometrical sizes were investigated using an oxyacetylene torch. Insignificant weight or configurational changes and the absence of surface cracks after testing were observed. The excellent resistance to thermal shock and ablation is attributed to the SiC addition. A satisfactory agreement between the measured temperature distributions and FEM computations was achieved. Results indicated that both the side length and radius of nose curvature exerted a prominent effect on the temperature gradient and thermal stress magnitude inside and/or on the surface of the pyramidal mockups. The magnitudes of heat flux and boundary layer temperature, Te influenced the head temperature, T1 and the undersurface temperature, T2 in a different way. A stronger heat flux yielded higher T1 value whereas T2 remained almost constant. Comparatively, Te showed a much more remarkable effect on T2 than it did on T1 owing to the different heat transfer mechanisms of these two parts.

► The ZrB2–SiC pyramidal bodies exhibited excellent ablation/oxidation resistance and configurational stability at ultra-high temperatures. ► Both temperature and thermal stress distributions inside and/or on the surface of specimens were remarkably influenced by the side length and nose tip curvature radius of the pyramid. ► The experimental and computational findings are beneficial to the rational design of the ultra-high temperature components with sharp nose tips and/or wing leading edges used in hypersonic aerospace vehicles and re-usable atmosphere re-entry vehicles.