A comparative study of the mechanical and tribological behaviours of different aluminium matrix-ceramic composites

Aluminium matrix composites (AMCs) have great potential for critical applications within aerospace, automotive, defence, marine, agriculture and nuclear engineering sectors. The composite materials are very attractive because of their good balance between lightweight versus high strength and machinability. Depending on the particular application, these properties can be further enhanced by adding silicon carbide, boron carbide and graphite, respectively. These reinforcements help to upscale the physical/mechanical properties in order to meet the novel industrial demand. In the present work, a novel hybrid composite is developed through stir cast welding technique. The novel materials manufactured are of great importance, because they exhibit higher mechanical properties and better wear resistance with respect to classical materials (i.e. pure aluminium). The results of mechanical test showed that the addition of 5% boron carbide content to aluminium matrix permits to enhance the tensile properties, shear strength and hardness values; 6% silicon carbide and 4% graphite allow to improve the flexural strength and wear rate, respectively. The best performance was obtained for aluminium composite with 5wt% boron carbide. The correlation between industrial requirements and the findings from this research indicates that the newly developed composite is an excellent candidate material for structural neutron absorber, armour plate and as a substrate material for computer hard discs.