MECHANICAL BEHAVIOUR, CORROSION AND WEAR CHARACTERISTICS OF ALUMINIUM HYBRID COMPOSITES REINFORCED WITH SILICON CARBIDE AND QUARRY DUST PARTICLES

Abstract

The mechanical behaviour, corrosion and wear characteristics of Aluminium based hybrid composites reinforced with silicon carbide (SiC) and quarry dust (QD) particles was investigated in this research. This was aimed at assessing the viability of utilizing cheaply sourced quarry dust particles as a complimentary reinforcing material to SiC for the development of low cost high performance aluminium matrix composites. QD mixed with SiC in weight ratios 0:1, 1:3, 1:1, 3:1, and 1:0 were utilized to prepare 8 wt. % of the reinforcement in the Aluminium based alloy using double stir casting process. Density measurement and microstructural examination and were used to evaluate the level of porosity and particle dispersion in the matrix. Hardness, tensile properties and fracture toughness were used to evaluate the mechanical behaviour while wear index and potentiodynamic electrochemical studies in 3.5 NaCl solution was used to assess the wear and corrosion behaviour of the composites. The results show that the porosity levels in all the composites produced were generally very low (< 2.5 %) and good dispersion of the particulates in the aluminium matrix was evident. There was marginal decrease in the hardness and wear resistance of 5 % and 9 % respectively with increase QD content. The tensile strength and the specific strength of the composites showed very close strength levels while the strain to fracture and the fracture toughness of the composites increased with increasing weight % of QD. The results also show that the composites produced when immersed in 3.5 weight % NaCl environment proved immune to attack and the quarry dust did not have any adverse effect on the corrosion resistance of the composites as the composite with 8 weight % QDP with the highest corrosion rate was less than 0.02 mmpy. The results from the research show that the use of quarry dust as single reinforcement or as hybrid reinforcement with silicon carbide has great prospect as it does not jeopardize the integrity of the material.