Mechanical Strength Increment in C _f /Al Composites Achieved by Optimizing Chemical Vapor Deposition‐SiC Interphase

To improve the mechanical properties of carbon fiber‐reinforced aluminum matrix composites (C f /Al) and protect the carbon fibers from damage, a SiC interphase is deposited onto the carbon fibers via chemical vapor deposition (CVD). The effects of interphase thickness on the microstructure, flexural resistance properties, and fracture behavior of composites are investigated. Transmission electron microscopy analysis demonstrates that the CVD‐SiC interphase effectively protects carbon fibers from erosion of high‐temperature Al melts, inhibiting Al diffusion into carbon fibers and preserving fiber integrity. Compared with the composites without SiC interphase, the flexural strength of the composites with a SiC interphase thickness of 1.93 μm has increased from 157.7 ± 0.9 to 409.8 ± 20.6 MPa. The CVD‐SiC interphase enhances fracture resistance by increasing crack path tortuosity and promoting energy dissipation through fiber pull‐out and interface debonding. However, an excessive thickness of CVD‐SiC may give rise to defects and pores within the fiber bundle, consequently decreasing the mechanical properties. This study offers meaningful insights for interface engineering in C f /Al composites and contributes to their potential structural applications.