Reactive sintering of electroless nickel-plated aluminum powders

Fine (about 2 mum) particle size aluminum powders were produced in a plasma reactor, in a flow of argon gas, and the particle size distribution analyz ed. A uniformly thick nickel film. was deposited on the aluminum powder par ticles by electroless nickel plating, thus providing more efficient surface contact than can be obtained using conventional methods such as mechanical mixing of nickel and aluminum powder. Nickel-plated aluminum compacts were subsequently sintered at various temperatures in argon and in vacuum, and Ni3Al intermetallic alloys produced. Differential thermal analyses, scannin g electron microscopy, and X-ray diffraction analyses of the sintered sampl es were carried out. Satisfactory densities of 99.8% were achieved by sinte ring in vacuum at temperatures as low as 680 degreesC. (C) 2001 Elsevier Sc ience Inc. All rights reserved.