Topological interlocking and damage mechanisms in periodic Ti ₂ AlC-Al building block composites

Ceramic Ti ₂ AlC building blocks of 4 × 1.24 × 1.24 mm³ size were prepared by injection molding and assembled to brick-and-mortar structures with tetragonal, monoclinic and triclinic unit cells. The single building blocks were bonded with an Al-loaded polysiloxane adhesive, which was afterwards pyrolized. Afterwards the 3D-assemblies were infiltrated with an Al-melt to fabricate dense 0–3 ceramic-metal composites. The influence of the unit cell of the resulting Ti ₂ AlC-Al composites was investigated regarding the mechanical properties and damage mechanisms in bending tests. The developed near-net shape fabrication process shows great potential to manufacture structured ceramic-metal composites with high toughness and complex shape. Due to their ductile behavior scaffold applications are possible. The calculated initial fracture toughness of monolithic Ti ₂ AlC could be improved from 5.0 MPa m ^0.5 to 14.5 MPa m ^0.5 for the monoclinic assembly and 14.7 MPa m ^0.5 for the triclinic assembly, corresponding to an increase of 191%.