Experimental study of ceramic coatings on lower-density ceramic substrates

Adhesion and homogeneity of the coating-substrate were analyzed on the basis of the establishment of coating mineralogy. Substrate raw materials used were kaolin clay and a calcined alumina 4 μm; a series of higher density ceramic coatings were deposited using calcined aluminas 0.5 μm and 4 μm, sili...

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Detalhes bibliográficos
Autores: Torres, Camila Irene, Miquelarena, C. P., Bianchi, Gustavo Luis
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2023
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositório:CONICET Digital (CONICET)
Idioma:inglês
OAI Identifier:oai:ri.conicet.gov.ar:11336/220205
Acesso em linha:http://hdl.handle.net/11336/220205
Access Level:Acceso aberto
Palavra-chave:AL2O3-SIO2-MGO
BRITTLE FRACTURE
CLAY SUBSTRATE
DIP COATING
SINTERING EFFORT
https://purl.org/becyt/ford/2.5
https://purl.org/becyt/ford/2
Descrição
Resumo:Adhesion and homogeneity of the coating-substrate were analyzed on the basis of the establishment of coating mineralogy. Substrate raw materials used were kaolin clay and a calcined alumina 4 μm; a series of higher density ceramic coatings were deposited using calcined aluminas 0.5 μm and 4 μm, silica fume, and talc. The dip coating technique was applied to all substrates and later sintered at 1300°C. Shrinkage and density of coatings mixtures and substrate were separately evaluated. X-ray diffraction was utilized to identify the crystalline phases present in the coatings, while optical and electron microscopy were employed for the structural characterization of the coatings. Coatings exhibited lower shrinkage compared to the substrate. Among the specimens that exhibited good adhesion, cracks were observed to extend parallel to the substrate surface. The presence of cristobalite on the coating indicated that the failure mechanism involved buckling. The crack dimension presented on the coating decreased after adding talc to the mixture.