Mechanical strength and corrosion rate of aluminium composites (Al/SiO₂): Nanoparticle silica (NPS) as reinforcement

The fabrication and characteristics of amorphous silica reinforced Al matrix composites are studied in this paper. The major starting materials were commercial Al powder and extracted nanoparticle SiO₂ (NPS) powder from Indonesian silica sands. Two different active solutions, namely N-butanol and tetramethylammonium hydroxide (TMAH), were introduced during synthesis. Characterisations in terms of physical, mechanical, microstructural and corrosion rate examinations were also employed. Introducing the SiO₂ nanoparticles into the Al matrix has decreased the density and increased the porosity of the composites. The addition of N-butanol into Al/SiO₂ (Al/SiO₂(B)) led to broader and lower X-ray diffraction profiles than the addition of TMAH (Al/SiO₂(T)). From the microstructural analysis, we found that the SiO₂ particles enter and agglomerate into the opening gap of the Al sheets. Furthermore, yield strength, ultimate compression strength and modulus of elasticity tended to reduce the addition of SiO₂. The corrosion rate of Al/SiO₂(T) was lower than that of Al/SiO₂(B) composites.