Reactive sintering of electroless nickel-plated aluminum powders

摘要

Fine (about 2 #mu#m) particle size aluminum powders were produced in a plasma reactor, in a flow of argon gas and the particle size distribution analyzed. A uniformly thick nickel film was deposited an the aluminum powder particles by electroless nickel plating, thus providing mare 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 Ni_3Al intermetallic allays produced. Differential thermal analyses, scanning electron microscopy, and X-ray diffraction analyses of the sintered samples were carried out. Satisfactory densities of 99.8 percent were achieved by sintering in vacuum at temperatures as low as 680 deg C.