Physical Properties of Fine Copper Powders by Disproportionation Reaction

Experimental condition to make fine copper powder by disproportionation reaction and the physical properties of powders obtained were studied.A 3 l-reactor to produce large amount of samples, similar to the 1 l-reactor described previously, was used. Fine copper powder (1-2μm) which was similar in shape and diameter to that with the 1 l-reactor was obtained.By use of the 3 l-reactor, the formation of larger copper powders more than 10μm which were surrounded with flat crystal surface planes could be achieved.Mixed powder, which consists 70% of large powder and 30% of small powder, showed the maximum tap density of 5.1g/cm3. Densely sintered product was obtained when mixed powders were sintered for 2.5 hours at 1, 000°C. Some results in thermomechanical analysis and SEM micrographs of sintered products are included.