Sintered feldspar glass–ceramics and glass–ceramic matrix composites

Sintering with simultaneous crystallization of fine glass powders allowed the preparation of dense glass–ceramics based on unusual feldspar crystals (constituted by microcline and orthoclase, KAlSi3O8), at a very low temperature (750 °C) and with limited processing times. Al2O3 platelets, added to the glass powders, caused a remarkable improvement of bending strength (exceeding 100 MPa), microhardness (approaching 9 GPa) and fracture toughness (approaching 2 MPa m0.5), even for limited concentrations (which varied from 5 to 15 vol%). Due to the simple and low cost manufacturing technique, the glass–ceramic matrix composites obtained could find applications in the construction industry.