Nanoparticles of Ni on Al2O3 Ceramic Powder Coated by Chemical Reactions
J. Michalski, K. Konopka and M. Trzaska
Warsaw University of Technology, Faculty of Materials Science and Engineering, Wołoska 141, 02-507 Warsaw, Poland
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Ceramic--metal composites are usually prepared by sintering ceramic with metal or metal oxide powders. An alternative technique is sintering ceramic powders coated by metal film. In the present study, the Ni coated Al2O3 powder was obtained by chemical reduction reaction. We used the phosphate bath for deposition of nickel--phosphorus on the surface of Al2O3 powder. The thickness and chemistry of Ni--P coating depend on the time and the parameters of the reaction process. Particles of Ni--P precipitate from a solution in two different forms: (a) spherical nanoparticles of Ni--P (50 nm) which grow on the surface of Al2O3 powder and can form tight, one diameter thick film; (b) large agglomerates of loosely connected spherical nanoparticles with a 50÷150 nm diameter. The method proposed in this study allows obtaining Al2O3 powder covered with Ni--P nanoparticles in the forms of thin film or single nanoparticles, mixed with loose Ni--P agglomerates.
DOI: 10.12693/APhysPolA.102.181
PACS numbers: 73.63.Bd, 81.07.Wx, 81.16.--c, 61.46.+w