Isotropic freeze casting of through-porous hydroxyapatite ceramics
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It has well known that hydroxyapatite (HA) is a kind of excellent materials for biomolecular absorption and separation, and the absorption and separation performances of HA would be improved if HA had been processed into desirable porous structures. In this paper, we reported on the combination of gel casting and freeze casting to develop the through-porous hydroxyapatite ceramic monoliths. Experiments demonstrated that the gel-containing freeze casting technique was an isotropic pore-forming technique and could prepare the near-net-shape forming green bodies with good mechanical strength no matter what the HA content in green bodies was. Further green body sintering formed the through-porous ceramics whose grain size, pore size, and porosity depended on and could be controlled by the content of HA in green bodies. The formation of through-pores in ceramics resulted from the gels and water in green bodies, which acted as the templates of the pores with size < 1 Lim and the pores with size >1 Lim, respectively. The gel-freeze casting technique is simple, repeatable, and cost-effective, therefore being hopeful for industrial applications.
Keywordsgel-freeze casting through-pores hydroxyapatite (HA) ceramics near-net-shape
This work was supported by the National Natural Science Foundation of China (Grant No. 31570977).
- Liu B, Lin PH, Shen Y, et al. Porous bioceramics reinforced by coating gelatin. J Mater Sci: Mater Med 2008, 19: 1203–1207.Google Scholar
- Reed JS. Critical issues and future directions in powder forming processes. In: Ceramic Transactions, Vol. 1, Ceramic Powder Science I1 (B). Messing GL, Fuller ER Jr., Hausner H, Eds. American Ceramic Society, 1987: 601–610.Google Scholar
- St Pierre PDS. Slip casting nonclay ceramics. In: Ceramic Fabrication Processes. Kingery WD, Ed. MIT Press, 1963: 45–51.Google Scholar
- Mangels JA. Injection molding ceramics. In: Proceedings of the 6th Annual Conference on Composites and Advanced Ceramic Materials: Ceramic Engineering and Science Proceedings, 2008.Google Scholar
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