LAUSR

Abstract Self-healing and oxidation of spark plasma sintered Ta2AlC was investigated using a newly developed wedge loaded compact specimen to determine strength recovery in a single specimen. Previous work had predicted dominant Al oxidation leading to dense and strong reaction products to result in favourable healing properties. However, crack-gap filling and strength recovery of Ta2AlC were not achieved by oxidation at 600 °C. Oxidation below 900 °C in synthetic and atmospheric air resulted in porous Ta-oxides, with no Al2O3 formation. DTA up to 1200 °C revealed a two-step reaction process with the final products Ta2O5 and TaAlO4. The study shows that the kinetics may overrule the self-healing MAX-phase design criteria based on thermodynamics.