Influence of Interfacial Shear Stress on First-Matrix Cracking Stress in Ceramic-Matrix Composites |
| |
Authors: | Raj N. Singh |
| |
Affiliation: | General Electric Corporate Research and Development Center, Schenectady, New York 12301 |
| |
Abstract: | The first-matrix cracking stress and fiber-matrix interfacial shear stress were measured in zircon-matrix composites uniaxially reinforced with either uncoated or BN-coated silicon carbide filaments to study the role of intentional changes in interfacial shear stress on first-matrix cracking stress. The first-matrix cracking stress was measured by mechanical tests performed in either tension or flexure, and the filament-matrix interfacial shear stress was measured by a fiber pushout test. The first-matrix cracking stress was independent of the measured interfacial shear stress and did not conform to the predictions of a number of energy-based micromechanics models. In contrast, the first-matrix cracking stress showed a good correlation with the first-matrix cracking strain, which is hypothesized to be a more realistic criterion for first-matrix cracking in this class of filament-reinforced ceramic-matrix composites. |
| |
Keywords: | cracking shear stress models composites |
|
|