Sintering of hydroxyapatite ceramics, with the aid of optical transmittance-temperature spectra

The optical transmittance - temperature spectra of well-translucent thin pe llets of hydroxyapatite prepared by the high isostatic pressure consolidati on of xerogel particles were measured by a newly-developed thermal analysis technique. From these spectra, it was possible to identify temperature int ervals with increased or decreased levels of light transmittance, clearly a ssociated with microstructural changes. The thermal processing of treated p ellets was stopped at temperatures deliberately chosen with respect to the specific transmittance states. Samples with increased transparency were pre pared when the heating of pellets was stopped at the temperatures of the lo cally highest light transmittance measured.