MAX Phase Coating for High Temperature and High Strength Control Surfaces

Missile defense interceptors experience very high axial and lateral accelerations as well as extremely stressful aerothermal environments during atmospheric operation. To maximize performance, control surfaces (e.g. fins, strakes, canards) must be a low-density, lightweight, and rigid structure that can operate at high temperature (up to 1400°C) in an oxidative environment. The MAX phase ternary carbide Ti3SiC2, or titanium silicon carbide, is a material of interest for missile control surfaces because it has a high stiffness, behaves plastically, is resistant to thermal shock, maintains its strength at high temperature, and is easily machinable. Multilayered coatings of Ti3SiC2 and SiC have demonstrated oxidation resistance and self-healing characteristics up to 1500°C and during thermal cycling. The multilayered coating can be combined with a lightweight and strong substrate, such as a carbon/carbon (C/C) composite, as an alternative to the steel alloys that are typically used. C/C composites are strong, lightweight structural materials that maintain their desirable properties at high temperatures, but they have a low oxidation threshold of ~370°C. A protective multilayered Ti3SiC2/SiC coating would prevent oxidation of the structural C/C and enable a low-density lightweight structural material for missile control surfaces. Approved for Public Release | 20-MDA-10643 (3 Dec 20)