Highly transparent α-alumina obtained by low cost high pressure SPS

Highly transparent pure alumina (65.4%) with an average grain size of 200 nm was fabricated using high-pressure (>400 MPa) spark plasma sintering. For the first time, highly transparent alumina ceramics were produced using low cost carbon fiber composite for the pressing punches. The high pressure device was also used to fabricate fully dense nanostructured alpha alumina with average grain size of 107 nm. The developed low cost high pressure sintering apparatus might be applied to produce a wide range of pore free nanostructured materials.