THE EFFECT OF SOL-GEL TECHNIQUE ON THE ALUMINIUM SiCp COMPOSITE

Abstract

Due to the low reactivity between the silicon carbide particulate (SiCp) and Aluminium
(AI) interface bonding strength. SiCp is treated by applying a coating on its surface. The
objective of this paper is to study the effect applying ceramic sol coating, which is silica
sol via sol gel technique onto SiCp The various concentrations applied are 2 wt%, 4 wt%
and IOwt% of silica sol. Aluminium metal matrix composite (AI-MMC) reinforced with
10% and 20% volume fraction of SiCp produced by powder metallurgy technique with
sintering temperature of 550 C was studied. The surface morphology of AI-MMC is
observed using SEM to examine the particle distribution, porosity and flow pattern. While
the degradation of SiCp due to interfacial reaction between the particulate and Al matrix is
examined by x-ray diffraction (XRD). SiC, degradation is evaluated by the ratio of the SiC
to the silicon (Si) XRD peak. From microstructure analysis, the specimens coated with
2 wt% and 4 wt% silica sol coating showed the best result which has uniform
reinforcement distribution. lower porosity and better flow pattern. For XRD analysis. the
best cotiing was obtained by 4 wt% silica sol concentration that has greater reaction
between Al and SiC .