Effects of Rare-earth Oxides Doping on Microstructures and Properties of Al2O3/TiAl Composites

Effects of rare-earth oxides addition (0.38 similar to 1.52 mol% of Sm2O3, Eu2O3 and Er2O3) on the property and microstructure of the hot-pressed (1300 degrees C, 2h, 35 MPa) Al2O3 (12 wt %)/TiAl in-situ composites have been investigated. The results show that the doping of rare-earth oxides has a positive effect on both mechanical properties and densities of Al2O3/TiAl composites. Densities enhanced with increasing of rare-earth oxides. The flexural strength and fracture toughness were higher than other samples when the rare-earth oxide content was 0.38 mol %. The matrix grains and Al2O3 particles were significantly refined, and Al2O3 particles evenly distributed in the matrix.