Mechanical Properties of La sub(2)O sub(3)-Al sub(2)O sub(3) Ceramics Prepared by Microwave Sintering

The influence of La sub(2)0 sub(3) on the phase and microstructure evaluation and mechanical properties of La sub(2)O sub(3)-Al sub(2)O sub(3) ceramics sintered with 2.45 GHz microwave energy was investigated. The results showed that La sub(2)O sub(3) could density the pure alumina with a lower sintering temperature and a short sintering time. La sub(2)O sub(3) reacted with Al sub(2)O sub(3) to form LaAl11O18 completely and the amount of LaAlllOlS increased with the increasing content of La sub(2)0 sub(3), distributing at the Al sub(2)O sub(3) grain boundaries. The specimen doped with 10 vol.% and 15 vol.% La sub(2)O sub(3) sintered at 1500 [degrees]C exhibited plenty of columnar grains with draw ratio about 1:4. The existence of columnar grains enhanced the micro hard ness and fracture toughness of La sub(2)O sub(3)-Al sub(2)O sub(3) ceramics.