Effect of MgO-Y2O3 Additions on Microstructure and Mechanical Properties of Al2O3-TiCN Composites

The effect of MgO-Y2O3 additives on densification, microstructure and mechanical properties of hot-pressed Al2O3-TiCN composites was studied. The MgO-Y2O3 additions had little influence on densification of Al2O3-TiCN composites. The Al2O3-TiCN composites without additives had coarsening microstructure, whereas that containing 0.25wt%MgO-0.5wt%Y2O3 had a noticeable finer microstructure and good mechanical properties. The increase of fracture toughness were attributed to the addition of MgO and Y2O3 together with the TiCN particles to inhibit the abnormal grain growth of Al2O3.