EFFECTS OF SINTERING TEMPERATURE ON THE DENSITY AND POROSITY OF SODIUM CHLORIDE PREFORMS FOR OPEN CELLED ALUMINIUM FOAM MANUFACTURING

Abstract

Effects of sintering temperature on the density and porosity of sodium chloride preforms for aluminium foam manufacturing have been investigated. Cold pressed salt preforms were sintered at 730^oC, 760^oC and 790^oC and different times ranging between 6- 18 hours in a carbolite furnace at a heating rate of 5^oC/minute. The Results of density and porosity measurements show that the density and porosity of the preform can be varied by changing the sintering temperatures of the preforms. It was observed that the density of the preforms increases with sintering temperature at constant time and pre-sintering pressure while porosity has an inverse relationship with temperature. Results of scanning electron microscopic analyses, show sintering connection (bonding) between the salt beads at all the temperatures in which sintering was performed. Sintering of the sodium chloride perform was attributed to grain boundary diffusion and evaporation condensation mechanisms.