Abstract
The effect of different calcination temperatures on the powder characteristics and the sintered density of synthetic hydroxyapatite (HA) powders, produced using two different processing routes, was examined. Powders were produced by either drying, milling and sieving an as-precipitated HA or by spray-drying a slurry of precipitated HA. Calcining the two powders at temperatures between 400 and 1000 °C did not significantly affect the powder particle size. The specific surface areas of the two powders, however, were reduced from 70–80 m2/g for a calcination temperature of 400 °C to approximately 5–7 m2/g for 1000 °C. Analysis of the surfaces of the HA powders using scanning electron microscopy (SEM) illustrated the coarsening and subsequent sintering of the sub-micron crystallites that constitute a powder particle as the calcination temperature increased, corresponding to the decrease in surface area of the powders. The sintered densities of the final ceramics were not significantly affected by calcining the powders. Microhardness measurements of ceramics prepared from powders calcined at different temperatures showed no significant variations with calcination temperature or powder processing method. The results of this study have illustrated that for applications where HA may be used in powder form, for example in plasma-spraying and for the production of HA-polymer composites, calcining the HA will significantly affect the powder properties, namely the surface area and morphology of the powders. For applications requiring HA in a dense ceramic form, for example as granules or blocks, calcining the powders does not significantly affect the properties of the final ceramic.
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T. KOBAYASHI, S. SHINGAKI, T. NAKAJ IMA and K. HANADA, J. Long-Term Effects Med. Impl. 3 (1993) 283.
J. D. DE BRUIJN, Y. P. BOVELL and C. A. VAN BLITTERSWIJK, Biomaterials 15 (1994) 543.
W. BONF IELD, M. D. GRYNPAS, A. E. TULLY, J. BOWMAN and J. ABRAM, ibid. 2 (1981) 185.
M. WANG, R. JOSEPH and W. BONF IELD, ibid. 19 (1998) 2357.
M. AKAO, H. AOKI and K KATO, J. Mater. Sci. 16 (1981) 809.
M. JARCHO, C. H. BOLEN, M. B. THOMAS, J. BOBICK, J. F. KAY and R. H. DOREMUS, ibid. 11 (1976) 2027.
P. E. WANG and T. K. CHAKI, ibid. 4 (1993) 150.
S. BSET and W. BONFIELD, J. Mater. Sci.: Mater. Med. 5 (1994) 516.
S. PUAJINDANETR, S. BSET and W. BONF IELD, Brit. Ceram. Trans. 93 (1994) 96.
M. G. S. MURRAY, J. WANG, C. B. PANTON and P. M. MARQUIS, J. Mater. Sci. 30 (1995) 3061.
A. J. RUYS, C. C. SORRELL, A. BRANDWOOD and B. K. MILTHORPE, J. Mater. Sci. Lett. 14 (1995) 744.
H. M. ROOTARE and R. G. CRAIG, J. Oral. Rehab. 5 (1978) 293.
P. LAYROLLE, A. ITO and T. TATEI SHI, J. Am. Ceram. Soc. 81 (1998) 1421.
M. A. FANOVICH and J. M. P. LOPEZ, J. Mater. Sci.: Mater. Med. 9 (1998) 53.
I. R. GIBSON, S. KE, S. M. BSET, W. BONFIELD, ibid.
PDF Card no. 9–432, ICDD, Newton Square, Pennsylvania, USA.
ASTM E 384–84 Standard test method for microhardness of materials. ASTM Committee on Standards, Philadelphia, USA, 1984.
T. KOKUBO, S. ITO, Z. T. HUANG, T. HAYASHI, S. SAKKA, T. KITSUGI and T. YAMAMURO, J. Biomed. Mater. Res. 24 (1990) 331.
P. LI, C. OHTSUKI, T. KOKUBO, K. NAKANISHI, N. SOGA, T. NAKAMURA and T. YAMAMURO, J. Mater. Sci.: Mater. Med. 4 (1993) 127.
P. LUO and T. G. NIEH, Mater. Sci. Eng. C-Biomimietic Mater Sensors and Systems 3 (1995) 75.
Idem. Biomaterials 17 (1996) 1959.
A. ROYER, J. C. VIGUIE, M. HEUGHEBAERT and J. C. HEUGHEBAERT, J. Mater. Sci.: Mater. Med. 4 (1993) 76.
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Patel, N., Gibson, I.R., Ke, S. et al. Calcining influence on the powder properties of hydroxyapatite. Journal of Materials Science: Materials in Medicine 12, 181–188 (2001). https://doi.org/10.1023/A:1008986430940
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DOI: https://doi.org/10.1023/A:1008986430940