Experimental investigation on the mechanical performance of the Al 2 O 3 and ZrO 2 added Al-Mg-Si alloy for structural applications

Abstract

The present-day structural application requires advanced materials at extreme conditions, and the development of it is not economically feasible. As a result, existing material in the composite form has more visibility to suit the purpose. The material's strengths and qualities must be examined before it can be recommended for use in harsh conditions. In the present study, Al₂O₃ (3, 6, 9, 12, and 15 wt.%) and ZrO₂ particles (2 wt.%) are reinforced with Al-Mg-Si alloy (Al 6061), which possess good isotropic behaviour and better interface bonding. The double stir casting process was adopted for the hybrid composite development, and the samples were cold rolled to reduce grain size and pores in the composites. The developed composites were subjected to mechanical characterisation tests such as hardness, tensile, compression, impact and flexural tests. An increase in reinforcement percentage enhances the mechanical properties. The improvement was attributed to the high thermal mismatch and reduction in the inter-particle distance by cold rolling and the reinforcements. Scanning electron microscope microstructural examination was conducted, and even dispersion of 3 to 15 wt.% Al₂O₃ reinforcements was observed. Tensile elongation decreases with an increase in reinforcement percentage. High elastic modulus and temperature mismatch between matrix and reinforcements increase the strength of the composites. The fracture behaviour of the composites generally showed dimples which are characteristics of ductile fracture, except at 15 wt.% Al₂O₃ / 2 wt.% ZrO₂ showed a large portion of cleavage planes and grain cracking. The Al-Mg-Si alloy is reinforced with 9 wt%. Al₂O₃ / 2 wt.% ZrO₂ had the best properties suitable for its use in different structural applications.