Comparison of Interfacial Mechanical Behavior of Continuous Carbon Fiber Composites Manufactured using Autoclave and 3D Printing Approach

The nanoscale interactions at fiber-matrix interfaces are critical to the mechanical performance of fiber reinforced composites. This study employs nanoindentation push-in tests to evaluate and compare the interfacial strength (IFS) of continuous carbon fiber composites produced through conventional autoclave processing and 3D printing (9T Labs FDM). We investigated three systems: neat carbon fibers infused in epoxy, autoclave-cured carbon/epoxy prepregs, and 3D-printed carbon/PEEK. Nanoindentation analysis of single fibers revealed the highest debond load for the autoclave-manufactured samples, indicating a superior interface. The 3D-printed composites exhibited intermediate IFS, stronger than the neat fiber system. These results highlight the significant influence of manufacturing techniques on interfacial mechanical properties, offering crucial insights for optimizing composite design and performance.