Fracture mechanism of BJ-CVI SiC lattices with four distinct structures based on finite element simulation and digital image correlation

• SiC lattices were fabricated with high precision and strength using BJ and CVI. • Fracture mechanism of SiC lattices was revealed using DIC and FEM. • Brittle fracture caused by microcracks at the stress concentration point. • Thin-walled lattice structures exhibit superior mechanical performance. SiC ceramic lattice structures (CLSs) have become increasingly popular in engineering applications due to their remarkable specific strength and thermal properties. To investigate their quasi-static compressive mechanical behavior, binder jetting additive manufacturing technology was used to produce various configurations of SiC CLSs, specifically Edge Center Cubic (ECC), Face Center Cubic (FCC) and Gyroid-type triply periodic minimal surfaces, namely the Gyroid-sheet (GSH) and Gyroid-skeletal (GSK). The findings reveal that the GSH configuration exhibits the highest quasi-static compressive strength at ∼ 54 MPa. The failure mechanism is characterized by a sequential propagation of damage. Micro-cracking initiates at points of peak tensile stress—specifically, at the nodes or on the strut surfaces. These cracks then extend through the strut cross-section. The failure of a single critical strut redistributes the load to its neighbors, inducing sequential overloading and fracture. This chain reaction ultimately leads to the catastrophic crushing of the entire structure along an inclined shear zone. This research offers valuable insights for optimizing the design and assessing the mechanical performance of SiC CLSs.