Self‐crack healing ability and strength recovery in ytterbium disilicate/silicon carbide nanocomposites1. Issue 1 (28th August 2018)

• Record Type: Journal Article
• Authors: Nguyen, Son Thanh; Nakayama, Tadachika; Suematsu, Hisayuki; Iwasawa, Hirokazu; Suzuki, Tsuneo; Niihara, Koichi
• Is Part Of: International journal of applied ceramic technology. Volume 16:Issue 1(2019)
• Page Start: 39
• Page End: 49
• Publication Date: 2018-08-28
• Subjects: crack healing -- nanocomposites -- silicate -- silicon‐carbide -- strength; Ceramics -- Periodicals; Ceramics -- Technological innovations -- Periodicals; 620.1405
• DOI: 10.1111/ijac.13089
• Languages: English
• ISSNs: 1546-542X

Abstract

Abstract: The SiO2 volatility and SiC recession in hydrocarbon‐rich combustion atmosphere is the main problem of SiC‐reinforced ceramics when they are utilized as coating materials for gas turbine blades. The composite of Yb2 Si2 O7 ‐Yb2 SiO5 /SiC is expected as a self‐crack healing material that can avoid this problem because the monosilicate can react with the SiO2 glass to form disilicate and hence further reinforce the composite. In this study, the composites, fabricated with various morphology of SiC nanofillers, were precracked and then heat‐treated in an oxidizing environment to activate their crack healing behavior. The healing effect as a function of filler morphology and annealing time was investigated. Healing mechanism and future applications of these composites were also discussed. Abstract : Schematic illustration of surface self‐crack healing and SEM micrographs of the turbine blade's topcoat nanocomposite. During operation of turbine at high temperature, monosilicate (bright gray) phase transforms into disilicate (dark gray) phase, indirectly help to close the surface cracks.