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

Abstract Alumina coatings were prepared using detonation gun from commercial powder (CP) and high energy ball milled powder (MP) with 83 nm crystallite size. The sliding wear rate and wear coefficient of friction were lower in the nanocrystalline powder coating. The coating from the as-received commercial powder consisted of thick splats, and a paucity of nanoparticulate inter-splat regions whereas milled powder coating has thinner splat morphology with nanoparticulate inter-splat regions. The nanoparticulate material in the inter-splat regions and the finer microstructure of the MP coating is believed to be responsible for improved wear resistance.