Role of nanocrystalline feedstock in the tribological behaviour of alumina coatings deposited by detonation gun

► Nanocrystalline and microcrystalline powders were used for D-gun alumina coating. ► Nanocrystalline powder coating was tribologically superior. ► The coatings fracture along inter lamellar boundary rather than crystallite boundary. ► Finer microstructure and nano-particulate inter splat regions improved tribological properties.