Abstract
A machinable glass ceramic is defined as a glass ceramic which can be turned, drilled, milled or threaded like metals while the application of such machines to the working of normal glasses or glass ceramics would cause the fracture of the workpiece. The aim of this study is to find out the crystallization behaviour and mechanical properties of machinable glass ceramics having different ratios of Na/K mica and apatite phases, to ascertain the best machinable composition. Raw materials were mixed and calcined at 950°C, then melted at 1350°C-1400°C and quenched to the water. Particles were prepared for DTA and XRD analysis. Microstructural characterization was carried out by using JEOL 7000-F model Field Emission Scanning Microscope. Microhardness measurement and machinability tests were performed. Optimum results were obtained by the composition, containing 70% Na/K mica and 30% apatite which had an average mica size of 3-4 microns. It was also observed that the use of water as a cooling agent improved the machinability.
Original language | English |
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Pages (from-to) | 9-17 |
Number of pages | 9 |
Journal | Journal of the Australian Ceramic Society |
Volume | 43 |
Issue number | 1 |
Publication status | Published - 2007 |
Keywords
- Fluorapatite
- Machinability
- Mica