Abstract:
In this work, anorthite have a chemical formula (CaO.Al2O3.2SiO2) was prepared from local kaolin and calcium oxide (CaO) extracted from CaCO3. In the first stage, two different methods were followed. The second method shows more efficiency, it gives a good sintering percentage over 96 % of anorthite theoretical density.
The effect of different amounts of (Na2CO3) and (Fe2O3) on the anorthite sintering and crystallisation was studied, 3 wt% sodium carbonate addition increases the density to values greater than 97 % of theoretical. Moreover, the density of about 98 % of the theoretical was reached for samples containing 1.5 wt% Fe2O3 sintered at 900 °C for 1 h and promotes anorthite crystallisation at lower temperatures. The anorthite phase appeared earlier at 850°C.
The prepared samples show a tensile strength of 82 MPa for 3% of Na2CO3 addition which corresponds to a flexural strength of about 222 MPa, a Vickers micro-hardness of 8.7 GPa that were treated at 900°C.
Excellent values of tensile strength about 96 MPa which corresponding to a flexural strength of 259 MPa, a Vickers micro-hardness of 9.1 GPa for the simples with 1.5 % weight of Fe2O3 were also obtained.
Finally, the bioactivity of anorthite by the possibility of formation of apatite on the surface of anorthite immersed in simulated body fluid (SBF) was confirmed.
