PRODUCTION OF SILVER - PALLADIUM ALLOY POWDER BY AEROSOL DECOMPOSITION

摘要

PURPOSE: To produce high-purity spherical dense silver-palladium alloy powder by heating an aerosol of an unsatd. soln. of a pyrolyzable silver-contg. compd. and a palladium-contg. compd. in a thermally volatile solvent at a specified concn. CONSTITUTION: A mixture unsatd. soln. of AgNO3 and Pd(NO3 )2 is prepared by using deionized water. The obtd. soln. is dispersed into droplets in a carrier gas such as nitrogen or air to produce an aerosol. The density of droplets is controlled to be enough lower than the density to cause 10% reduction in the density due to collision and aggregation. Then the obtd. aerosol is heated to the operating temp. at which (1) the solvent water is volatilized, (2) AgNO3 and Pd(NO3 )2 are decomposed to produce finely devided particles of Ag, Pd, Ag-Pd alloy or their mixtures, and (3) these particles are converted into an alloy having the melting point lower than the melting point of the Ag-Pd alloy. Thus, sufficiently densified fine particles of Ag-Pd alloy are obtd.