Effect of SiC coating on interfacial reaction between carbon short fiber and Al melt

This study aims to investigate the effects of SiC coating on the degradation of carbon short fiber in Al melt. The SiC coating on the surface of carbon short fiber is performed at 1500 degrees C in Ar atmosphere by carbothermal reduction method after precoating with silica sol on the surface of carbon short fibers. The SiC coating layer is successfully formed with amean thickness of 160 nm. The pure carbon short fibers without SiC coating was degraded rapidly in Al melt. After maintenance for 180 min in Al melt of 800 degrees C, carbon fibers did not remain. On the other hand, the carbon short fibers with SiC coating layer maintained the shape of initial carbon fiber up to 180 min in Al melt. However, with increase of reaction time in Al melt, SiC coating layer gradually dissolved and after 180 min, the coating layer was not observed in some areas on the surface of fiber. Also, concentration of Al in carbon fiber increased with the maintenance time in Al melt. As a consequence, SiC coating layer can retard effectively degradation of the carbon short fibers, even though it is only a few hundred nanometers thick. Copyright (C) 2010 John Wiley & Sons, Ltd.