3D-printed SiC lattices integrated with lightweight quartz fiber/silica aerogel sandwich structure for thermal protection system

A lightweight thermal protection/insulation integrated sandwich structure for the aerospace thermal protection system (TPS) was developed with the aim of achieving superior mechanical strength and thermal insulation properties. On the one hand, the lattice frameworks of silicon carbide (SiC) ceramic thermally insulated components with body-centered lattice core (BCLC) were fabricated by selective laser sintering (SLS) 3D printing technology; on the other hand, the sol–gel process was applied to fill quartz fibers reinforced silica (Qf/SiO2) aerogel into the hollow parts of the BCLCs to form a sandwich structure, thus further enhancing the mechanical and thermal insulation properties. To explore the impact of lattice core structure gradient on performance, we designed two types of BCLCs, single-layer one and double-layer one. By comparing the properties of the sandwich structures with the BCLCs, it was found that after the hot surface temperature was kept at 1000℃ for 1500 s, the backside temperature of the single-layer and double-layer sandwich structures decreased by 69.15℃ and 112.73℃, respectively, implying that the thermal insulation efficiency increased by 8.75 % and 13.85 %, respectively. Remarkably, it was precisely due to the filling of the Qf/SiO2 aerogels that the compressive strength of the single-layer and double-layer sandwich structures reached 119.41 MPa and 35.16 MPa, respectively, which were successfully improved by 238.56 % and 256.23 %, respectively, in comparison with the BCLCs structures. Consequently, this study provides an efficient and reliable method for the preparation of thermal protection/insulation integrated components by using 3D printing technology combined with the sol–gel method, which has broader significance among academic and industrial communities.