Cold spraying demonstrates great potentials in fabrication of metal matrix composites. In this study, a nickel-coated Al_2O_3 powder, which is produced through a hydrothermal hydrogen reduction method, was employed aiming at increasing the volume fraction of ceramic particles in the cold sprayed composite. The effect of oxidation temperatures on the microstructure and microhardness of cold-sprayed and heat-treated Ni-Al_2O_3 composite coatings was examined. In addition, the oxidation behaviors of these two types of composite coatings were discussed. Results show that the oxidizing has a significant effect on the microstructure and microhardness of the cold-sprayed Ni-Al_2O_3 composite coating and the morphologies of oxide films are obviously different under different heat treatments.
展开▼
