The Effect of SiC and MgO Ceramic Reinforcements on the Mechanical Behavior and Electrical Properties of the Composite Structure in Al7075/SiC/MgO Hybrid Composites

Abstract

In this study, certain technical properties of new generation aluminum-based composites, obtained by combining the Al7075 alloy widely used in the industrial field with two different ceramics, were investigated. For this purpose, SiC and MgO ceramics in particle form were reinforced into the Al7075 matrix material using powder metallurgy technique and composite structures were produced in three different reinforcement ratios. Measurements to determine electrical resistance and conductivity and bending and compression strength tests were performed on the obtained composite structures. The density and porosity amounts of the composite structures were also determined, and their microstructures were examined with a digital microscope. With the increase of SiC/MgO amount in the aluminum composite structure, the electrical resistance increased, and the conductivity value decreased. With the effect of SiC/MgO reinforcing materials, the density value of the composite structures decreased while the amount of porosity increased. The hardness values increased due to the effect of SiC and MgO ceramics in the structure. The bending and compression strength values initially increased and then started to decrease with the increase of reinforcement ratios. It has been determined that the formation of porosity in the composite structure negatively affects the mechanical behavior. The second important factor was evaluated to be the amount and shape of ceramic-based reinforcement particles in the structure. Due to the effect of SiC, which has very high electrical resistance, and MgO, which has dielectric properties, the electrical conductivity values of the composite structures decreased. The increase in electrical resistance and the decrease in electrical conductivity were directly proportional to the amount of ceramic-based reinforcement particles in the composite structure.