Researchers at the Department of Materials, Imperial College London, have developed a novel extrusion technique to fabricate alumina platelet-reinforced (10 vol%) glass matrix composites. The glass matrix starting powder was obtained from processing recycled television glass. Extrusion was carried out at a relatively low temperature (700 deg C) and the processing parameters, such as extrusion die geometry, heating time of the composite pellet prior to extrusion and rate of extrusion, were optimised. The final microstructure revealed the preferred orientation of the reinforcing alumina platelets in the matrix and the absence of significant residual porosity. The hardness of extruded samples as found to depend on the degree of platelet orientation, reaching values >6 GPa.
