Premium
Effects of Interfacial Films on Thermal Stresses in Whisker‐Reinforced Ceramics
Author(s) -
HSUEH CHUNHWAY,
BECHER PAUL F.,
ANGELINI PETER
Publication year - 1988
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.1151-2916.1988.tb07560.x
Subject(s) - whisker , materials science , composite material , thermal expansion , mullite , ceramic , brittleness , ceramic matrix composite
Toughening of whisker‐reinforced (or fiber‐reinforced) ceramics by whisker pullout requires debonding at the whisker/matrix interface. Compressive clamping stresses, which would inhibit interface debonding and/or pullout, are expected in composites where the matrix has a higher thermal expansion coefficient than the whisker. Because such mismatch in thermomechanical properties can result in brittle composites, it is important to explore approaches to modify the thermal stresses in composites. As a result, the effects of a film at the whisker/matrix interface on the stresses due to thermal contraction mismatch upon cooling are considered in this study. Analysis of various properties of the film are considered for the whisker/matrix systems, in particular for SiC/Al 2 O 3 , SiC/cordierite, and SiC/mullite composites. Reduction of thermomechanical stresses is shown to occur when the interfacial film has a low Young's modulus. Also, when the whisker has a lower thermal expansion coefficient than the matrix (e.g., SiC/Al 2 O 3 ), the interfacial stresses generated during cooling decrease as the thermal expansion coefficient of the film increases.