Determination of fracture strength and fracture energy of (metallo-) ceramics by a wedge loading methodology and corresponding cohesive zone-based finite element analysis

A wedge loaded testing methodology to determine the fracture energy and strength of (semi-) brittle (metallo-)ceramics is presented. The methodology combines a tailored specimen geometry and a comprehensive finite element analysis based on cohesive zone modelling. The use of a simulation-based approach to extract both fracture strength and...

Autonomous high-temperature healing of surface cracks in Al₂O₃ containing Ti₂AlC particles

In this work, the oxidation-induced crack healing of Al₂O₃ containing 20 vol.% of Ti₂AlC MAX phase inclusions as healing particles was studied. The oxidation kinetics of the Ti₂AlC particles having an average diameter of about 10 μm was studied via thermogravimetry and/or differential thermal...

Repeated crack healing in MAX-phase ceramics revealed by 4D in situ synchrotron X-ray tomographic microscopy

MAX phase materials are emerging as attractive engineering materials in applications where the material is exposed to severe thermal and mechanical conditions in an oxidative environment. The Ti2AlC MAX phase possesses attractive thermomechanical properties even beyond a temperature of 1000 K. An attractive feature of this material is its...

Demonstrating the self-healing behaviour of some selected ceramics under combustion chamber conditions

Closure of surface cracks by self-healing of conventional and MAX phase ceramics under realistic turbulent combustion chamber conditions is presented. Three ceramics namely; Al₂O₃, Ti₂AlC and Cr₂AlC are investigated. Healing was achieved in Al₂O₃ by even dispersion of TiC...

A conceptual study into the potential of MAX-phase ceramics for self-healing of crack damage

The reduction of maintenance and replacement work costs is an important driving force in the development of high temperature materials (T>800 °C) that can autonomously heal damage as a result of local cracks. In recent years some potential routes involving the addition of sacrificial particles have been identified, yet these systems have the...

A conceptual study into the potential of max-phase ceramics for self-healing of crack damage

The reduction of maintenance and replacement work costs is an important driving force in the development of high temperature materials (T>800 °C) that can autonomously heal damage as a result of local cracks. In recent years some potential routes involving the addition of sacrificial particles have been identified, yet these systems have the...