Titanium aluminide composites reinforced with in situ formed Al 2O3 were fabricated by a reactive hot press method;
using Cr2O3;
Al and Ti powders as raw materials. The effect of Cr2O3 addition on the microstructures and mechanical properties of the (Ti;
Cr)Al/Al2O3 composite was characterized. The results show that the TiAl matrix is refined gradually with increasing the amount of Cr2O3. The Vickers-hardness and densities of the (Ti;
Cr)Al/Al2O3 composite increase gradually with increasing Cr2O3 content. When the Cr 2O3 content is 4.47 wt.%;
the compressive strength;
flexural strength and fracture toughness of the composite reach the maximum values of 1032 MPa;
634 MPa and 9.78 MPa m1/2;
which are substantially higher than those of the monolithic TiAl based alloy by about 18%;
78%;
and;
80.5%;
respectively. The increase in mechanical properties for the (Ti;
Cr)Al/Al2O3 composite is due to the toughening effect arising from the combination of Cr solid solution in TiAl matrix and in situ formed Al2O3. © 2013 Elsevier B.V. All rights reserved;