Crystallisation in fluorapatite-fluorphlogopite glass ceramics

Moorehead, RD

Abstract

Apatite based glass-ceramics are some of the most bioactive materials found to
date. They do not require fibrous encapsulation and bond to bone directly
through an apatite layer. Apatite based glass-ceramics exhibit relatively poor
biaxial flexural strength, hence limiting their applications to non-load bearing
implants. The addition of mica results in a material that is highly machinable, and
provided that a suitable interlocking microstructure can be produced, the
strength will be increased.
The aim of this work is to investigate how altering the heat treatment affects the
crystallisation and the final mechanical properties of three different
compositions of glass-ceramic. The glass system studied is the ternary glass
system; barium fluorphlogopite (Bao.sMgafSiaAlOiojFz), fluorapatite
(CaiofPO^eFz) and cordierite (MgzAUSisOis). The three compositions differ by
the mol% of fluorapatite forming feedstock in the precursor glass. Glass-ceramics
formed by heat-treating a glassy precursor are investigated using differential
scanning calorimetry, kinetic neutron diffraction and scanning electron
microscopy. The mechanical properties of the samples are characterised by their
biaxial flexural strength and Vickers hardness. The phases formed and the
microstructures of the samples are linked to the mechanical properties and an
assessment of the final material's implant suitability is made.

Citation

Moorehead, R. Crystallisation in fluorapatite-fluorphlogopite glass ceramics. (Thesis). Salford : University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2011