Interfacial frictional stresses and fracture toughness of biomorphic graphite/copper interfaces

• A wood-derived biomorphic graphite/copper composite comprises two interpenetrating networks.
• A fiber push-in test is adapted to measure the interfacial frictional stresses.
• Interfacial frictional stress and fracture toughness depend on roughness and mechanical interlocking.
• The interfacial property values are comparable to other metal-ceramic composite systems.

A fiber push-in test was adapted to measure the interfacial frictional stresses present in wood-derived biomorphic graphite/copper interpenetrating phase composites. Additionally, a sandwich composite was used to measure the interfacial fracture toughness of the copper/graphite system. Results indicate that due to poor wetting of copper on graphite, the surface roughness and extent of mechanical interlocking between the two phases determine the mechanical characteristics of the interface, and that the values are comparable to other metal-ceramic composite systems with limited bonding. A characterization of the mechanically bonded interfaces is vital to understanding load transfer, thermal cycling effects, contact resistance, and thermal conductivity.

Figure optionsDownload as PowerPoint slide