Ti-Al intermetallic compounds are promising materials for structural application. Processing of Ti/Ti-Al layered materials by self-propagating high temperature synthesis was tried in order to enhance the crack propagation resistance of intermetallics. Tensile test, three-point fracture toughness test and in-situ observation of crack propagation were employed in these materials, and the effect of microstructure and volume fraction of intermetallic layer on the crack propagation behavior was investigated and this paper was aimed at understanding the fracture mechanism of these materials. Tensile strength was increased with the decrease of volume fraction of intermetallics layer, and the materials with many microcracks during tensile test demonstrated higher elongation regardless of the volume fraction of intermetallic layer. The crack propagation resistance curve was quantitatively predicted from the contribution of bridging mechanism in the materials where crack propagates forward during fracture toughness test. The proposed criterion for crack propagation orientation could also predict whether crack propagates forward or deflects in the intermetallic layer.
