Abstract – The purpose of this study is to characterize the microstructural and mechanical behavior of Al-SiC composites produced by the high-energy ball milling process (HEBM). Gas atomized AA2017 aluminum alloy powder with the particles size of <100 and silicon carbide (SiC) powder particles with an average particle size of <1 μm composites were successfully produced using HEBM process. The milling process was performed using the laboratory scale HEBM machine called Simoloyer CM08 ZOZ GmbH for 5 h. The effect of milling time on the microstructure and mechanical properties of AA2017-SiC composites during the mechanical milling process was investigated. The microstructures of the composite powder samples at different milling times were examined using optical microscopy (OM), Scanning electron microscopy (SEM), and X-ray diffraction (XRD) technique. The OM and SEM investigation confirmed that the SiC particles were homogeneously dispersed in the AA2017 matrix material after 5 h of milling. The XRD analysis was carried out to determine the phase constituents and crystallite size of the composites powder at various milling times. The XRD results showed that the crystallite size of the Al matrix reduced and the lattice strain increased with increasing milling time. So, the average crystallite size and lattice strain of the AA2017 + 10 vol.% SiC composites were reduced from 300 nm to 64 nm and increased from 0.1 to 0.5 %, respectively after 5 h of milling. The micro-hardness of the powder particle samples was measured using the Wilson Microhardness tester with an indentation load of 10 gf. It was observed that hardness increased for all samples with increasing the milling time. The average microhardness of the AA2017-SiC composites obtained after 5 hours of milling was higher than the unmilled powder particles.
Keywords: Al-SiC composites, High-energy ball milling, crystallite size, lattice strain, microhardness