Thermal Expansion of Composites as Affected by the Matrix

Summary and Conclusions Thermal expansion measurements of composite systems containing hard dispersions embedded in brittle and semibrittle matrices indicate the importance of (1) the magnitude of the stress developed in the matrix and (2) the crack propagation behavior of the matrix. The thermal expansion of these composites can be predicted if the residual stress developed as a result of the difference in the expansions of the components does not exceed a critical value defined by the modified Griffith equation. This critical stress varied considerably with the nature (brittle, semibrittle, or ductile) of the matrix.