Print Email Facebook Twitter Autonomous high-temperature healing of surface cracks in Al2O3 containing Ti2AlC particles Title Autonomous high-temperature healing of surface cracks in Al2O3 containing Ti2AlC particles Author Boatemaa, L. (TU Delft (OLD) MSE-1) Bosch, Myrthe (Student TU Delft) Farle, A.M. (TU Delft (OLD) MSE-5) Bei, G. (TU Delft (OLD) MSE-1) van der Zwaag, S. (TU Delft Novel Aerospace Materials) Sloof, W.G. (TU Delft (OLD) MSE-1) Date 2018 Abstract 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 analysis. Surface cracks of about 80 μm long and 0.5 μm wide were introduced into the composite by Vickers indentation. After annealing in air at high temperatures, the cracks were filled with stable oxides of Ti and Al as a result of the decomposition of the Ti2AlC particles. Crack healing was studied at 800, 900, and 1000°C for 0.25, 1, 4, and 16 hours, and the strength recovery was measured by 4-point bending. Upon indentation, the bending strength of the samples dropped by about 50% from 402 ± 35 to 229 ± 14 MPa. This bending strength increased to about 90% of the undamaged material after annealing at 1000°C for just 15 minutes, while full strength was recovered after annealing for 1 hour. As the healing temperature was reduced to 900 and 800°C, the time required for full-strength recovery increased to 4 and 16 hours, respectively. The initial bending strength and the fracture toughness of the composite material were found to be about 19% lower and 20% higher than monolithic alumina, respectively, making this material an attractive substitute for monolithic alumina used in high-temperature applications. Subject aluminaMAX phaseoxidation kineticsself-healingTiAlC To reference this document use: http://resolver.tudelft.nl/uuid:a3fcbbc4-c9ca-4ef7-a422-56980bcb9798 DOI https://doi.org/10.1111/jace.15793 ISSN 0002-7820 Source Journal of the American Ceramic Society, 101 (12), 5684-5693 Part of collection Institutional Repository Document type journal article Rights © 2018 L. Boatemaa, Myrthe Bosch, A.M. Farle, G. Bei, S. van der Zwaag, W.G. Sloof Files PDF Boatemaa_et_al_2018_Journ ... ociety.pdf 2.28 MB Close viewer /islandora/object/uuid:a3fcbbc4-c9ca-4ef7-a422-56980bcb9798/datastream/OBJ/view