Authors
Abstract
This work focuses on studying the role of drying and calcination on
stiochiometry and crystallinity of deposited HA. Also, studying the effect of sintering
temperature on phases generated, physical and mechanical properties of sintered HA
powder compact at a range of (800-1200) ˚C.
Both Ca/P ratio and crystallinity were increased after calcination, where the Ca/P
ratio raised from 1.7 to 1.9 and the height of Hydroxyapatite peak intensity was also
increased .Secondary phases also appeared.
X-ray diffraction patterns and electrical microscopic pictures of polished surfaces
of the Hydroxyapatite compact after sintering had revealed the process of
densification and crystallization of Hydroxyapatite . The increase of sintering
temperature leads to grain growth, while surface cracking and other defects became
lower i.e. porosity and surface voids.
Both hardness and fracture strength were increased for samples sintered at high
temperatures where they reached their maximum values at sintering temperature
(1200)ºC .The maximum linear shrinkage was 20% at sintering temperature 1200ºC.
The maximum bulk density was (2.173) g/cm3 at sintering temperature of 1200ºC
and the maximum apparent density was (2.58) g/cm3 at sintering temperature 900ºC.
The maximum apparent and open porosities were 47.136% and 47.058% respectively
at sintering temperature 900ºC. The maximum water absorption was 39.13% at
sintering temperature 800ºC.
Keywords
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