1. What typical density levels are obtained in sintered ceramics?
2. What do the terms ‘‘apparent porosity'' and ‘‘true porosity'' of ceramics mean?
3. The specific gravity of Al2O3 is 3.96 g/cm3. A ceramic part is produced by sintering alumina powder. It weighs 80 g when dry, 92 g after it has soaked in water, and 58 g when suspended in water. Calculate the apparent porosity, the true porosity, and the closed pores.