Microstructure and mechanical behaviour of eutectoid corundum-rutile composites

Dense corundum/rutile composites were obtained through two different processing routes: (a) decomposition of Al2TiO5 compacts, and (b) conventional sintering of Al2O3/TiO2 powder compacts. Decomposition of Al2TiO5 yielded microstructures consisting of thin hexagonal plate-shaped corundum particles with high aspect ratio embedded in a rutile matrix. These composites exhibited a bending strength of up to 250 MPa and indentation toughness of 5-7MPa m1/2 depending on the annealing conditions. The results are compared with those obtained on conventionally sintered Al2O3/TiO2 composites.This work has been supported by CICYT, Spain, under project number MAT88-0156. The award of a fellowship to H. Wohlfromm by the Commission of the European Communities is gratefully acknowledgedPeer reviewe