Aluminum Phosphate Ceramics

A review of aluminium phosphate chemically bonded phosphate ceramics (CBPCs) is provided. After a brief discussion of aluminium phosphate dental cements, the kinetics of formation of these ceramics is discussed and optimal conditions required to form them are derived. Aluminum being a trivalent metal, it has a very low solubility and hence formation of CBPCs is difficult. However, the theoretical analysis presented in this chapter shows that very low pH coupled with slightly elevated temperature (150°C) provides the right conditions. Experimental verification of the formation of these ceramics using the optimal conditions is discussed in detail. Mineralogical analysis of the resulting product shows that it is berlinite, one of the most stable CBPCs.