Mechanical and Microstructural Response of Aluminum Composites Reinforced with Ceramic Micro-Particles

Aluminum matrix composites have recently taken an important role in advanced applications because they have a good combination of physical and chemical properties. For this reason, in this work, aluminum composites, with additions of ceramic particles (mullite or tungsten carbide), were manufactured in order to determine the effect of those particles on the mechanical properties and microstructure of aluminum. The manufacture of the composites was carried out by means of powder metallurgy. We studied composites with additions of 0.5 and 1 vol.% of the respective ceramic. Composites were sintered at 580 and 601 °C, which corresponds to 88 and 91% of the melting point of aluminum, respectively. Observations in SEM, together with EDX analysis, confirm that mullite particles are located at intragranular and transgranular positions of the aluminum matrix, while tungsten carbide particles were found mostly at intragranular areas of the matrix. From the analysis of the studied ceramics, it was found that with the use of mullite, there are greater improvements in the hardness and elastic modulus of the manufactured composite.