Mechanical behavior of anodic alumina coatings reinforced with carbon nanofibers

Anodic alumina was reinforced with three types of carbon nanofibers differing in the orientation of their graphene structure-perpendicular to the fiber axis, and parallel to the fiber axis both with dense core and hollow core (i.e., nanotubes). This study was designed to identify potential toughening and damage tolerant mechanisms in these nanoscale fiber-reinforced composite coatings. The dense carbon fibers improved contact damage resistance and reduced frictional resistance in sliding contacts. The hollow core reinforcements were much more promising for improving the fracture toughness of the composite coatings.