Transparent alumina fabricated by SPS sintering with AlF3 doping

Transparent alumina was fabricated by spark plasma sintering with AlF 3 doping at a high heating rate of 100   °C   min −1 and a moderate loading pressure of 73   MPa. The sintered AlF 3 -doped alumina was dark in color due to light absorption by F − substitution and by the resulting defects induced in the alumina lattice. An AlF 3 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 .