Enhancing Interfacial Interlocking in PBF additive manufactured CF/PEEK Composites via ZnO Nanoparticle Surface Modification

ZnO@CF hybrids were prepared via wet-chemical deposition followed by thermal treatment. • ZnO surface modification increased CF surface roughness and favored interfacial interlocking. • ZnO@CF/PEEK exhibited higher complex viscosity and storage modulus than CF/PEEK. • 10-ZnO@CF/PEEK achieved a UTS of 125.4   MPa, 8.1% higher than 10-CF/PEEK. Powder bed fusion (PBF) of carbon fiber-reinforced polyether ether ketone (CF/PEEK) composites is often constrained by weak fiber–matrix interfacial bonding. Here, ZnO nanoparticles were deposited onto milled CFs via an in situ wet-chemical route to enhance mechanical interlocking. ZnO surface modification increased CF surface roughness (8.2 to 11.3   nm) and specific surface area (by 57.2%). While slightly increasing melt viscosity, ZnO@CF significantly improved composite mechanical properties: 10-ZnO@CF/PEEK achieved an ultimate tensile strength of 125.4   MPa (8.1% higher than 10-CF/PEEK), and 15-ZnO@CF/PEEK reached a Young’s modulus of 8.80   GPa and a flexural strength of 181.9   MPa. Fracture surface analysis confirmed enhanced matrix adhesion on pulled-out fibers, demonstrating effective interfacial stress transfer driven by nanoscale topographical features. This work provides an efficient strategy for interfacial regulation in additively manufactured PEEK composites. Download: Download high-res image (266KB) Download: Download full-size image