Microstructure and mechanical properties of quasi-eutectic Al2O3-Y3Al5O12-ZrO2 ternary composites rapidly solidified from melt

The formation, microstructure and mechanical properties of Al2O3-Y3Al5O12-ZrO2 composites rapidly solidified from melts is presented. The studied compositions were inside the eutectic line between the Al2O3-Y3Al5O12 binary eutectic and the ternary eutectic, inside the Al2O3-Y3Al5O12-ZrO2 region of the Al2O3-Y2O3-ZrO2 ternary oxide diagram. Composites showing an homogeneous structure and phase distribution could be obtained in spite of the high thermal residual stresses generated upon cooling. The three-phase composites obtained by melt quenching have interphase spacings in the sub-micron range, due to the rapid growth during quenching. The fracture toughness of the ternary composites was measured by Vickers indentation methods. (C) 2003 Elsevier B.V. All rights reserved.