Fluoridation and Mechanical Properties of Hydroxyapatite with Addition of TiF3, Al2O3 and Fe2O3 by Sintering

Fluoridated composite Hydroxyapatite biomaterial was prepared by sintering the hydroxyapatite Ca10 (PO4)6. (OH)2[HA] powder with addition of titanium fluoride 30 wt. % -TiF3 and mixture of iron oxide and aluminum oxide [5 wt. %-Al2O3/Fe2O3 ; (5/1)]. The pellets were prepared by conventional sol-gel technique. The as-prepared samples were sintered at various temperatures and the effect of different temperature on grain size and mechanical properties has been investigated. The samples were sintered at various temperatures of 1100-1400 °C. After sintering, the sample’s mechanical properties such as compressive strength, bending strength, Vickers hardness were improved to be 49±0.26-103±0.26 MPa, 19.6±0.20-36.2±0.20 MPa, and 7.97±0.16-12.50±0.16 GPa with their grains size 4.76±0.10-17.63±0.10 μm and bulk densities 1.8944-2.2426 g/cm3.

The Refinement Effect of Al-Ti-C-RE Master Alloy Prepared by Adding Ce2O3 on Pure Al

The effect of Ce2O3 on the fabrication of the Al-Ti-C-RE refiner prepared by adding a powder mixture of potassium titanium fluoride and carbon into the aluminum melt was studied by means of the OM, XRD, ESEM and EDAX etc. It found that the addition of Ce2O3 increases the reaction rate between the potassium titanium fluoride and carbon during the fabrication of the Al-Ti-C-RE refiner making the Al3Ti and TiC phases well distributed. Moreover, the Ce2O3 is an intensive kind of the surface activation element strongly sticking to the Al3Ti phase after reacting on the master alloy observed by ESEM, which formed a new rare earth compound phase [AlTiCe] and accelerated the synthesis rate of TiC particles. And adding 0.15wt% Al-Ti-C-RE alloy can refine the pure Al strongly and remarkably, in which the grain size of pure Al is lower than 94.2μm. When the holding time of refining exceeded the 120 minutes, the refining effect on the pure Al has not faded remarkably, which proves the Al-Ti-C-RE prepared by the Ce2O3 have long-life and stable refining effects.