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

• DOI: 10.1111/jace.15793
• Publication Date: 2018-05-25T16:40:46Z
• Authors: Linda Boatemaa; Myrthe Bosch; Ann‐Sophie Farle; Guo‐Ping Bei; Sybrand van der Z...; Willem G. Sloof
• Keywords: Indentation; Thermogravimetry

Abstract In this work, the oxidation‐induced crack healing of Al 2 O 3 containing 20 vol.% Ti AlC MAX phase inclusions as particles was studied. The oxidation kinetics having an average diameter about 10 μm studied via thermogravimetry and/or differential thermal analysis. Surface cracks 80 long and 0.5 wide were introduced into composite by Vickers indentation. After annealing in air at high temperatures, filled with stable oxides a result decomposition particles. Crack 800, 900, 1000°C for 0.25, 1, 4, 16 hours, strength recovery measured 4‐point bending. Upon indentation, bending samples dropped 50% from 402 ± 35 to 229 14 MPa. This increased 90% undamaged material after just 15 minutes, while full recovered 1 hour. As temperature reduced 900 800°C, time required full‐strength 4 respectively. initial fracture toughness found be 19% lower 20% higher than monolithic alumina, respectively, making attractive substitute alumina used high‐temperature applications.