| Abstract Scope |
Ultra-high-temperature ceramics (UHTCs, e.g. SiC, ZrC, TiC, TiN) are optimal structural materials for applications that require extreme temperature resilience (Mp>3000°C), resistance to chemically aggressive environments, wear, and mechanical stress. To date, processing UHTC’s with laser-based additive manufacturing (AM) has not been fully realized due to a variety of obstacles: high laser energy densities are required to overcome slow diffusion rates, yet localized laser exposure induces decomposition or microcracking when a UHTC’s thermal capabilities are exceeded. To circumvent such issues, we propose an alternative technique for AM-UHTC processing by synthesizing the non-oxide material in-situ, during part formation. Specifically, we demonstrate that by employing laser-induced gas-solid reactions, reaction-bonded, near net-shaped UHTCs may be fabricated using AM compatible techniques. While this method presents a host of additional processing considerations (e.g. reaction kinetics, precursor microstructure, etc.), we demonstrate how this reactive approach may be viable for AM of refractory carbide, nitride, and composite materials. |