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Processing and Surface Flaw Tolerance of Alumina Bilayers
Author(s) -
Montgomery John K.,
Faber K. T.
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00073.x
Subject(s) - materials science , indentation , composite material , bilayer , porosity , layer (electronics) , ultimate tensile strength , surface layer , modulus , surface (topology) , membrane , chemistry , geometry , mathematics , biochemistry
Alumina bilayers of different relative thicknesses and densities were produced with a strong interface using a modified gel‐casting technique. Tolerance to surface damage is examined using biaxial flexure of disks damaged with a single Vickers indentation at various loads. The greatest surface flaw tolerance is seen in bilayers consisting of a thin porous layer on the tensile surface coupled to a thick dense layer. Here, the modulus mismatch causes redistribution of the applied stress, and fracture initiates at the internal porous‐dense interface rather than at the surface from the introduced indentation flaw.