EFFECT OF GREEN DENSITY ON THE SUBSEQUENT DENSIFICATION AND GRAIN-GROWTH OF ULTRAFINE SNO2 POWDER DURING ISOCHRONAL SINTERING

An ultrafine powder of SnO2 has been synthesized by a gas flow condens ation method. The average particle size of the powder was about 40 nm, The effect of the green density on the subsequent densification and g rain growth of the ultrafine SnO2 during sintering has been studied. A loose green compact consolidated under 500 MPa (green MC) showed rapi d densification as well as rapid grain growth at relatively low sinter ing temperatures. A dense green compact fabricated under 4.5 GPa (gree n GC) exhibited a slow increase in the density and almost no grain gro wth even at high sintering temperatures.