SiC-fibre reinforced glasses — electrical properties and their application

Silicon carbide fibre reinforced glasses were investigated to create smart materials. The fibres were used not only as reinforcement but also as electrical sensors to detect the degree of damage or the temperature change of the specimen. Investigations showed that the electrical properties of the composite are not only influenced by the inlaid fibres but first of all by the in-situ formed carbon interface layer. Because of the electrical conductivity of the inlaid fibres and the fibre/matrix interface, the electrical properties of the composites have been used to detect the development of damage during mechanical testing. The development of damage due to fibre fracture and delamination under applied mechanical load in a unidirectionally reinforced specimen was monitored and a micro deformation analysis was performed simultaneously. Furthermore, local changes in temperature could be detected. Several measurements were taken to localize mechanical damage and temperature.