Temperature-dependent fracture behaviour of superstructure Hf6Ta2O17 from ambient temperature to 1600°C. Issue 21 (1st November 2022)

• Record Type: Journal Article
• Authors: Wu, Q.; Cao, K.; Sun, Y.; Li, C.; Yang, L.; Zhou, Y.C.
• Is Part Of: Ceramics international. Volume 48:Issue 21(2022)
• Page Start: 31461
• Page End: 31469
• Publication Date: 2022-11-01
• Subjects: High-temperature mechanical properties -- Elastoplastic finite element simulation -- Hf6Ta2O17 ceramic -- Superstructure toughening mechanism -- Brittle-ductile transition; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.07.057
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: H f 6 T a 2 O 17 has shown great promise as a high-performance thermal barrier coating (TBC) for aeroengines because of its low thermal conductivity and strong resistance against calcium-magnesium-alumino-silicate (CMAS). Investigating the mechanical characteristics and failure mechanisms of H f 6 T a 2 O 17 ceramic materials at high temperatures is crucial for developing novel TBCs. In this study, H f 6 T a 2 O 17 was prepared by hot pressing 16 mol% Ta-doped H f O 2 powders in a vacuum, followed by annealing and pressureless sintering in air. The fracture toughness of the synthesised H f 6 T a 2 O 17 gradually decreased from 3.8136 M P a m 1 / 2 to 0.5806 M P a m 1 / 2 with the increase in the temperature from 25°C to 1600°C. Furthermore, the superstructure toughening mechanism and brittle-ductile transition mechanism were discussed in this paper. The results are beneficial in evaluating the effects of high temperature on the mechanical properties of H f 6 T a 2 O 17 .