Role of SiC ceramic particles on the physical and mechanical properties of Al–4%Cu metal matrix composite fabricated via mechanical alloying

Abstract

In the present investigation, Al–Cu composites with SiC particulates were fabricated via mechanical alloying process. The aim of this study was to evaluate the effect of milling time (8, 12, 16 and 32 h), particle size (30 nm and 15 µm) and volume fractions (5, 10 and 15 wt.%) of SiC particles on the metallurgical and mechanical properties. Scanning electron microscopy equipped with X-ray diffraction method was used to investigate the microstructural evolution and morphological changes created during mechanical alloying. Microstructural study indicated that SiC particles were well distributed after the mechanical alloying process. A homogenous distribution of the particles was obtained by 15 wt.% of SiC particles in the aluminum matrix. The results revealed that the SiC particle size also affected the distribution and size of the powders in the matrix and it improved as particle size decreased from 15 µm to 30 nm. The study of mechanical properties clearly showed that a reduction in hardness of composite occurs which is attributed to positive effect of reinforcement particles in resistance to the movement of dislocations. Furthermore, it was found that the wear weight loss of Al–Cu/SiC composite decreases monotonically with increasing SiC content and more uniform particle size distribution. The excellent wear rate was primarily attributed to uniform distribution of the SiC particles.