Paper number 106

MEASUREMENT OF MICRO-MECHANICAL INTERFACIAL PROPERTIES OF SIC (NICALONTM) FIBRE/BOROSILICATE GLASS MATRIX COMPOSITES AT ELEVATED TEMPERATURES BY THE SEM-PUSH-OUT TECHNIQUE

A. R. Boccaccini1, J. Janczak-Rusch2, E. Leopold3, R. Conradt3, L. Rohr2, H. Kern1

1FG Werkstofftechnik, Technische Universität Ilmenau,
D-98684 Ilmenau, Germany
2Swiss Federal Laboratories for Materials Testing and Research,
CH 8600 Dübendorf, Switzerland
3Institut für Gesteinshüttenkunde, RWTH Aachen,
D-52064 Aachen, Germany

Summary Results on both room and elevated temperature interfacial testing conducted on SiC (NicalonTM)-fibre reinforced borosilicate glass matrix composites by fibre push-out are presented. A scanning electron microscope push-out apparatus enabling testing and simultaneous observation of the experiment was employed. Using a conical diamond indenter with a flat end, single fibres were pushed out of thin polished composite sections in the temperature range from 23 to 500 °C. Applied force and displacement of the fibres were digitally monitored during debonding and frictional sliding. It was found that with increasing testing temperature, the interfacial shear stresses changed. Between 350 and 500 °C, a significant increase of the characteristic stresses was measured. This stress increment was very pronounced for T > 450 °C, and it was attributed to the variation of the properties of the glass matrix as the temperature approached the glass transition temperature (Tg = 530 °C). A slight decrease of interfacial shear stresses was measured at lower temperatures (T < 350 °C). This was attributed to the relaxation of internal stresses created in the composite due to thermal expansion mismatch.
Keywords interfacial properties, fibre push-out technique, interfacial shear stresses, glass matrix composites, high-temperature interfacial properties.

Theme : Interface and Interphase ; Mechanical Properties

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