Fabrication and characterization of Al 5005 composite with hybrid (Al2O3 and SiO2) reinforcement

Abstract

The suitability of using silica and alumina as reinforcement particles for aluminium metal matrix composites (AMMCs) cannot be overemphasized. There are only few researches reported on aluminium 5000 series and virtually none of aluminium alloy 5005. This alloy shows the lowest strength, cheap and high corrosion resistant. Therefore, the present study aimed at enhancing its strength using silica and alumina while maintaining it desirable properties. An experimental design with three factors comprising hybrid reinforcement addition of 3%, 6% and 9% termed as A, B, and C respectively was developed. Each factor was divided into 5 levels R1 to R5. Hence, the samples were tagged AR1 to AR5, BR1 to BR5, and CR1 to CR5 and control making a total of 16 samples. The mechanical and physical properties of the produced composites were investigated. The maximum UTS of 144 MPa was achieved with the hybrid composite of sample BR3 at 6% reinforcement and yielded the UTS 40% higher than the control sample. The maximum compression strength of 275 MPa was achieved also with BR3 at 6% reinforcement which improved the compressive strength by 33%. The maximum theoretical density of 2813 kg/m³ was obtained with CR5 at 9% reinforcement i.e. an increase of 3%. When comparing the density of the sample with highest UTS (BR3), 2736 Kg/m³ with the control sample, the difference was less than 1% for any increase of UTS up to 40%. This confirmed why the attraction of AMMCs. Whereas mechanical properties are improved by little change of density. 75% of the produced composites have porosity less than 4%, this meets the maximum permissible porosity in metal castings. The micrograph with the best UTS properties of sample BR3 showed a good incorporation and distribution of the reinforcement particles in the aluminium alloy 5005.