Preparation of Bimodal Porous Apatite Ceramics through Slip Casting Using Fine Hydroxyapatite Powders
A bimodal porous hydroxyapatite (HAp) body with high flexural strength was prepared through slip casting. HAp fine powder used in this study was synthesized by wet milling, drying and heating of a mixture of calcium hydrogen phosphate di-hydrate and calcium carbonate. The synthesized HAp powder was 0.320.05 μm in size and 38.10.8m2/g in specific surface area. The slip was prepared by adding deflocculant and foaming reagent. The optimum value for the minimum viscosity in the present HAp slip with respect to its solid loading and the optimum amount of the deflocculant were studied. The total porosity of the specimens obtained from a slip of 48 wt% HAp solid loading is in the range of 49 – 61vol %, and the resultant porous HAp sintered body had large spherical pores of 300 -m with interconnecting rectangular voids. Many small pores in the size range of 2-3 -m or below were observed in the specimen obtained by heating at 1100, and 1200 . The flexural strength of the bimodal porous HAp ceramics sintered at 1200 C showed a large value of 17.6 MPa, with a porosity of 60.5vol.
T. Ohji, T. Sekino and K. Niihara
Y. Zhang et al., "Preparation of Bimodal Porous Apatite Ceramics through Slip Casting Using Fine Hydroxyapatite Powders", Key Engineering Materials, Vols. 317-318, pp. 723-728, 2006