Fabrication and characterization of porous hydroxyapatite/β-tricalcium phosphate ceramics by microwave sintering

Microwave processing of porous hydroxyapatite/beta-tricalcium phosphate ceramics (BCP) was investigated in a dual frequency microwave-sintering furnace. Through the optimization of sintering conditions, such as the sintering temperature, the heating rate and the holding time, porous bioceramics with average crystal size of 300 nm, porosity of 65%, and compressive strength of 6.40 MPa were prepared. The results revealed that microwave-sintering process could get a sintered ceramic more rapidly at much shorter sintering time and lower sintering temperature than that of the conventionally heat sintering process. Furthermore, the microwave-sintered samples showed much smaller grain size and more uniform microstructure and resulted in bioceramics with a comparable compressive strength of that obtained in conventional method. The mechanism of rapid heating behavior of BCP ceramics in microwave was also discussed. The results revealed that microwave processing was a promising method for sintering porous BCP ceramics.