Microstructural Characterization of Mg-SiC Nanocomposite Powders Fabricated by High Energy Mechanical Milling

Abstract

Mg–SiC nanocomposite powders, with SiC particles of 50 nm size, were synthesized by mechanical alloying starting from a mixture of 80 vol.% pure Mg and 20 vol.% SiC powders. The effect of milling time on the microstructure properties of nanocomposite powders during mechanical alloying was investigated. The structural evolution during milling was monitored using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray mapping and X-ray diffraction methods. Using the Williamson-Hall equation, crystallite size and lattice strain of nanocomposite powders were estimated with broadening of XRD peaks. XRD results showed that the crystallite size of magnesium reached 49.52, 15.76 and 12.73 nm, respectively after 5, 15 and 25 h milling, also a uniform distribution of the SiC reinforcement in the Mg matrix was successfully obtained after milling the powders for 25 h.