The present contribution is addressed to offer an overview of recent achievements on some borides-based composites that are conventionally classified as ultra-high temperature ceramics (UHTCs) for their extremely high melting points.UHTCs are actively studied as key enabling technology for thermal protection structures (TPS) like wing leading edges, surface control components to be applied in the next generation of space vehicles flying at hypersonic speed or/and re-entering the Earthu27s atmosphere: increased performances and better maneuvrability are gained only through the design of very sharp profile. Sharp wedges and test articles with blunter profiles were fabricated in the ZrB2 base system, using SiC particulate or SiC short fibers as second phase: microstruture and fundamental thermo-mechanical characteristics were determined. The dynamic response to oxidation of such UHTCs was studied under aero-thermal heating using high enthalpy supersonic flows in arc-jet plasma wind tunnel. Microstructural changes were analyzed and correlated to specimenu27s size and shape and test conditions through Computational Fluid Dynamics (CFD) simulations
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