Preparation, mechanical properties and corrosion behaviors of oriented Ca(PO3)2 glass–ceramics

Highly oriented Ca(PO3)2 glass–ceramics were prepared by interface-induced nucleation. A polycrystalline Al2O3 plate was inserted into the Ca(PO3)2 glass melt. The crystallographic c-axis of most crystals were oriented in the direction perpendicular to the surface of Al2O3 plate. The strongly oriented glass–ceramics showed notable anisotropic properties. The anisotropic mechanical properties were studied by Vickers microhardness test and the influence of crystal alignment on corrosion behaviors in simulated body fluid (SBF) was investigated by measuring and comparing the changes of surface roughness from 3D surface topography, using a confocal laser scanning microscopy (CLSM). The experimental results revealed that the measured hardness of two different crystal alignment directions showed the indentation size effect (ISE), the true hardness on the sample cut parallel to the Al2O3 plate was 500 MPa larger in comparison to the one cut perpendicular to the Al2O3 plate. During immersion in SBF for 12 days, the crystal aligned parallel was easier to be attacked by solution, and had a more rough surface than the crystal aligned perpendicularly.