Transparent alumina fabricated by SPS sintering with AlF3 doping

Transparent alumina was fabricated by spark plasma sintering with AlF3 doping at a high heating rate of 100 °C min−1 and a moderate loading pressure of 73 MPa. The sintered AlF3-doped alumina was dark in color due to light absorption by F− substitution and by the resulting defects induced in the alumina lattice. An AlF3 doping concentration of 0.1% was found best for producing transparent alumina. A possible mechanism was proposed to explain the doping effect under the present sintering condition.