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Effect of Surface Flaw Size on Fracture Strength of Alumina Ceramics
Author(s) -
Ikeda Kiyohiko,
Igaki Hisashi
Publication year - 1987
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.1151-2916.1987.tb04942.x
Subject(s) - knoop hardness test , indentation , materials science , composite material , fracture (geology) , indentation hardness , bending , flexural strength , ceramic , scanning electron microscope , residual stress , fracture mechanics , microstructure
Semielliptical surface flaws of different sizes were introduced into Al 2 O 3 by Knoop microhardness indentation. The specimens were fractured by four‐point bending and the profiles of the indentation flaws were determined by observing the fracture surfaces with a scanning electron microscope. The relation between the indentation flaw size and the fracture strength could be well explained by applying the fracture‐mechanics analysis for semielliptical surface flaw in bending. The calculated values of the as‐indented critical stress intensity factor, K IC , were lower than previously reported presumably because of the influence of the residual stresses produced by the indenter.