Abstract
Directionally solidified oxide ceramic eutectic in situ composites are promising candidate materials for high-temperature structural applications in oxidizing environments. The rapid solidification characteristics of ternary metastable eutectic composition of Al 2O 3/YAG/YSZ in situ composite ceramics grown by laser zone-remelting technique are investigated. The fracture toughness and crack propagation behavior of the as-solidified composites are examined by the Vickers indentation technique. The metastable eutectic Al 2O 3/YAG/YSZ ceramic consists of Al 2O 3, YAG and YSZ phases, showing a typical ultra-fine irregular lamellar microstructure morphology with eutectic spacing as fine as 0.5 μm. Moreover, the ternary eutectic microstructures with coupled growth characteristics are also formed at the off-eutectic composition, effectively enlarging the eutectic growth range. The mean fracture toughness of the metastable eutectic Al 2O 3/YAG/YSZ ceramic is 3.9 ± 1.0 MPa m 1/2. The addition of ZrO 2 which weakens the interface bonding between YAG and Al 2O 3 phases, crack deflection, branching and microcrack toughening are the predominant toughening mechanisms.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
