Transactions of the INDIAN CERAMIC SOCIETY Vol. 58 1999
Synthesis and Sintering of Hydroxyapatite
in Presence of Oxide Additives
R. RAMACHANDRA RAo AND T. S. KANNAN
Pages : 64-68
DOI : 10.1080/0371750X.1999.10799863
Abstract
Hydroxyapatite (HAP) has been synthesised in the presence
of Al10 3 and Zr01 additives by solid state reaction between
tricalcium phosphate (TCP) and Ca(OHh at 1000°C/8 h. The
doping by Al10 3 and Zr01 resulted in the formation of
CaAI10 4 and t-Zr01 as the secondary phases by partial
consumption of CaO which in turn leads to the appearance
of~-TCP along with HAP. The amount of HAP in the product
is further reduced due to decomposition into ~-TCP and CaO
when these powder products are pelletised and sintcred at
1300°C for 2 h. While in Al10 3 doped samples, CaO after
reaction with Al10 3 and/or CaAI10 4 results in the formation
of CaAI10 4 and/or CaAI40 7, in Zr01 doped samples t-Zr01
and CaZr03 are formed by solid-solution of CaO into Zr01.
The products will have lower density as compared to pure
HAP without additives owing to the differential shrinkage
between the various phases present in the product.