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.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:539133 |
| Date | January 2011 |
| Creators | Moorehead, Robert David |
| Publisher | University of Salford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://usir.salford.ac.uk/26825/ |
Page generated in 0.0021 seconds