ZrO_2-TiN Composites

摘要

1.75 mol % Y_2O_3-stabilized ZrO_2-based composites with 35-95 vol % TiN were fully densified by hot pressing for 1 hour at 1550℃ under a load of 28 MPa. The TiN grain size was found to increase with increasing TiN content, resulting in a decreasing hardness and strength. The best mechanical properties, i.e., an indentation toughness of 5.9 MPa.m~(1/2) in combination with a Vickers hardness of 14.7 GPa and an excellent bending strength of 1674 MPa were obtained for the composites with 40 vol % TiN. The active toughening mechanisms were identified and their contribution to the overall composite toughness is discussed. Transformation toughening was found to be the primary toughening mechanism in all investigated composites.