CO-CONDENSATION PROCESS OF HIGH-TEMPERATURE METALLIC VAPORS

Co-condensation was examined to investigate the possibility of synthesizing ultrafine alloy particles from a vapor state. Experimental investigations were made for Nb-Al and Nb-Si systems by using an rf plasma evaporation method. Two kinds of metallic vapors in a plasma flame were quenched and deposited on a water-cooled copper surface. X-ray diffraction analysis revealed the formation of NbAl//3 and Nb//5Si//3. Several theoretical investigations were also made about the quenching rate of the vapors. Nucleation temperatures of Nb, Al, and Si according to the Lothe-Pound theory and particle growth history of Nb.