Oxidation resistance and failure behaviour of environment barrier coatings for Cf/SiC ceramic. (July 2014)

• Record Type: Journal Article
• Authors: Fan, J. J.; He, S. M.; Chang, Z. D.; He, L. M.; Wang, F. C.
• Is Part Of: Materials research innovations. Volume 18(2014)Supplement 4
• Page Start: S4-1112
• Page End: S4-1114
• Publication Date: 2014-07
• Subjects: Environment barrier coatings, -- Oxidation, -- Failure behaviour; Materials -- Research -- Periodicals; Matériaux -- Recherche -- Périodiques; 620.1105
• DOI: 10.1179/1432891714Z.000000000858
• Languages: English
• ISSNs: 1432-8917

Abstract

Abstract : Si+mullite/BSAS (1– x BaO– x SrO.A12 O3 –2SiO2, 0≤ x ≤1)+Er2 SiO5 environment barrier coatings (EBCs) were prepared by electron beam physical vapour deposition and plasma spraying for Cf /SiC substrates. The oxidation resistance and failure mechanism of the EBC were investigated by oxidation tests at 1400°C, X-ray diffraction and scanning electron microscopy. The results show that the local EBCs fell off after 133 h oxidation at 1400°C. The main cause of EBC failure is the formation of a glass phase and pores in the interface and intermediate layer of EBCs due to the reaction of Er2 SiO5 in the top layer with Si/SiO2 and Al/A12 O3 in the intermediate layer. In addition, the increased stress in the EBCs because of phase transformation and coefficient of thermal expansion mismatch of coating materials accelerated the EBC failure.