Effect of Glass Content on the Properties of Carbon-Glass Fiber Composite Materials

Abstract

Ten samples of glass fiber-phenol resin laminate with different glass content were carbonized at 1000, 1200, 1400 and 16000C in the atmosphere of inert gas and several properties of the carbonized products were examined.
Flexural strength of the samples, heat-treated at lower temperature than 1200C, increases with the elevation of glass content. But for samples, heat-treated at higher temperature than 140000, this tendency is less remarkable. Flexural strength samples with the same glass content deereases with the rise of heat treatment temperature (HTT),
True density and bulk density increase with elevation of glass content, but porosity has a reverse tendency.
Volume electric resistance of composites carbonized at 1000 C increases with the elevation of glass content, ancl for samples with the same glass content it decreases with the rise of HTT,
Photographs of the scan-ning electron microscope show that glass fiber begins to adhere each other at 14000C and otherwise adhesion between matrix and glass fiber is improved above 14000C, ln spite of these facts, flexural strength of carbonized samples decreases with the rise of HTT, This may be attributed to the fact that carbon atoms diffuse into glass fibers and make them brittle as described in the previous paper.