Flexural strength of in-situ reaction processed Al₂O₃-Al₃Ti-Al composites

Fully dense Al₂O₃-Al₃Ti-Al in-situ reaction composites have been synthesized by a combining squeeze-casting technique with combustion synthesis utilizing the reaction between TiO and pure Al. The spherical Al₂O₃ particles with a size of 0.1 μm to 1 μm were uniformly distributed in matrix. The results show that composites possess high flexural strength (410-490 MPa) and elastic modulus (156-216 GPa). With increasing the content of Al, the bending strength begins to increase slightly and then decreases, when the volume fraction of Al exceeds 40%. The elastic modulus of the composites decreases, when the content of Al increases. The high flexural strength of in-situ composites is mainly attributed to the dispersion strengthening of fine Al₂O₃ particles and Al₃Ti phase.