Powder Technology, Vol.203, No.2, 176-179, 2010
Fabrication and characterization of porous silver powder prepared by spray drying and calcining technology
High porosity porous silver powder with about 100 mu m average size and 5 mu m pore size was fabricated by spray drying and calcining technology. Effects of calcining temperature and process of spray-dried powder on the phases, grain size, particle morphology and pore microstructure of silver powder were investigated. The results showed that porous silver with approximately spherical shape and via hole structure was obtained using 0.25 mol Ag2CO3 solution of ammonia water, which was spray-dried at 200 degrees C and calcined at 400 degrees C for 30 min with heat treatment technology curve of gradient temperature in air. And there were not Ag2CO3, Ag2O and AgO phases existing in the porous silver. However, using 0.25 mol Ag2CO3 solution of ammonia water, the porous silver powder could not be fabricated by spray pyrolysis technology with a solution feed rate of 300 mL/h, flux of carrier gas of 0.30 MPa, and 640 degrees C furnace set temperature. (C) 2010 Elsevier B.V. All rights reserved.
Keywords:Metals and alloys;Chemical synthesis;Heat conduction;Scanning electron microscopy;X-ray diffraction