THERMAL-EXPANSION BEHAVIOR OF FIBER-REINFORCED DURAN GLASS

The thermal expansion coefficients of DURAN glass reinforced by SiC an d various carbon fibres are determined in order to investigate the inf luence of the different types of fibres and the preparation parameters on the thermal expansion behaviour of the composites. The coefficient of thermal expansion decreases with increasing Young's modulus of the fibres and with increasing fibre volume content. Composites with high -modulus carbon fibres and/or with high fibre volume concentration sho w a transition from contraction at lower temperatures to expansion at higher temperatures. ''Zero expansion composites'' can be produced for certain temperature intervals by selection of the fibre types and the fibre volume concentration. The experimentally determined expansion c oefficients are compared with the theoretically calculated ones by the mixing rule. The agreement is very good for the high-modulus fibres, less good for the high-strength fibres.