Developing high toughness laminated HfB2-SiC ceramics with ductile Nb interlayer

Herein, laminated HfB2-SiC/Nb ceramic with multi-layered structure was synthesized via tape casting and spark plasma sintering. Despite minor loss in strength of laminated HfB2-SiC/Nb ceramics (447 +/- 12 MPa) compared with that of monolithic HfB2-SiC ceramics (470 +/- 16 MPa) following the introduction of ductile weak Nb interlayer, fracture toughness of laminated ceramics reached 14.22 +/- 0.6 MPa m(1/2), showing an improvement of similar to 129% in comparison with monolithic ceramics (6.11 +/- 0.3 MPa m(1/2)). Cooperative toughening mechanisms of crack behavior (deflection and delamination) and plastic deformation (dimples and tear ridges) led to the improvement in toughness. This research provides novel strategy for the development of heterogeneous ceramic-metal layered composites with superior fracture toughness.