Mechanical and electrochemical behaviour of aluminum-based hybrid composites reinforced with silicon carbide and pride of barbardos seed ash produced by stir casting

Abstract

Aluminum matrix composite (AMCs) represent a class of MMCs having characteristics of low density, high stiffness and strength, superior wear resistance, controlled co-efficient of thermal expansion, high fatigue resistance and better stability at elevated temperature. These properties made AMCs a good candidate for the design of various components for advanced engineering applications.1 It has been found that the use of AMCs in engine applications can reduce the overall weight, fuel consumption and pollution in the automobiles and aircrafts.2 MMCs reinforced with ceramic particles are very promising materials for structural applications due to excellent combination of properties.3 AMCs reinforced with either silicon carbide (3.18g/cm3) or alumina (3.9g/cm3) particles are attractive materials for aviation.4,5 Some of the reinforcements are denser than aluminum alloys (2.7g/cm3) and therefore increase the weight of the composites produced depending on the quantity of the reinforcement added.6 Moreover, ceramic particles addition to the Al-alloy increases the hardness and thereby making machining more difficult.6 Hybrid composites, in most cases possess superior strength than monolithic composite. The properties of the hybrid reinforcements (primary and secondary) can be combined to attain better material properties. More so, the use of stir casting method for production of AMCs reduces the cost of the composite.7 Current trends in AMCs show growing concern in the production of hybrid Aluminum Metal Composites (HAMCSs) with better physical and mechanical properties. Resent researches have shown that agro/industrial waste materials such as fly ash, graphite, rice husk ash, amongst others, can be successfully used as a complementary reinforcement in AMCs.7,8 Furthermore, the use of hybrid reinforcements increases the service performance of the composites by the formation of new features. These agro/industrial wastes can reduce the cost of aluminum composites. Secondly, the weight of the composite can be manipulated due to lower density of this agro/industrial waste materials.3 Thirdly, these composites can also offer competitive physical and mechanical properties.7 This research investigates the mechanical and corrosion behavior of Aluminum-hybrid composite produced by reinforcing Aluminum 6063 with pride of Barbados seed ash and silicon carbide via double stir casting method.