Improvement of mechanical properties of Al2O3/Ti3SiC2 multilayer ceramics by adding SiC whiskers into Al2O3 layers

Al2O3/Ti3SiC2 multilayer materials with high mechanical properties in terms of bending strength and work of fracture have been prepared by in situ hot-pressing at 1600 °C for 4 h. In order to further improving the mechanical properties, SiC whiskers were added to Al2O3 layers as the 2nd-level toughening agent. With the content of SiC whisker increasing, the bending strength and work of fracture showed a similar trend of increasing firstly and then decreasing. Hence, the optimal mechanical properties of 688 MPa for bending strength and 2583 J/m2 for work of fracture were obtained when the added content of SiC whisker was 20 wt%. These excellent properties should be attributed to 1st-level toughening mechanism (multilayer structural toughening), 2nd-level toughening mechanism (whisker toughening), and the synergy effect between them. Hence, adding SiC whiskers was an effective approach to improving the mechanical properties.