Parametric effects on secondary deposition modification of 2D SiC_f/SiC film cooling hole structures

SiC_f/SiC composite materials, with advantages such as high temperature resistance and low density, have gradually become an important means of improving the overall performance of engines. For hot components, which require active cooling, the film-hole structure not only disrupts the continuity of the fibers and the matrix, reducing the material's load-bearing capacity, but also forms a new mass transfer channel for the Chemical Vapor Infiltration (CVI) process, which can generate a reinforcement effect through re-deposition. Mechanical tests were performed on perforated 2D SiC_f/SiC composites with controlled variables: deposition time, hole diameter, secondary deposition treatment after perforation. Full-field strain distribution was characterized by digital image correlation (DIC), while damage behavior was monitored via scanning electron microscopy (SEM). This approach investigated the coupled effects of deposition parameters and structural features on secondary deposition modified perforated SiC_f/SiC. Longer first deposition time reduces specimen surface damage and strain levels, but simultaneously diminishes the effectiveness of secondary deposition. Hole diameter significantly influences maximum strain and strength; moreover, secondary deposition strengthening intensifies with larger hole diameters. Distinct failure modes underscore complex interactions among deposition time, hole diameter, and secondary deposition. The established process-structure-property model provides critical theoretical support for integrated design of ceramic matrix composite (CMC).