Friction surfacing: A tool for surface crack repair

Abstract The present work demonstrates the feasibility of friction surfacing as a tool to repair surface cracks. An artificial crack, made on Inconel 718 plate was repaired by depositing a self-mating coating by friction surfacing. The crack was completely filled and the coating exhibited sound bonding with the substrate. For complete filling of the crack, the optimized process parameters depends on the crack dimensions. The coating microstructure was characterized by equiaxed fine grains with an average grain size of 1–3 μm and with a high fraction (>78%) of high angle grain boundaries. The microstructure in the coating evolves through dynamic recrystallization process, driven by combination of high strain rate and high temperature during friction surfacing. The method opens up a new way of repairing surface cracks and enhancing the service life of engineering components.