Influence of Milling Time on the Crystallite Size of AlSi5Cu2/SiC Composite Powder

AlSi₅Cu₂/SiC nanocrystalline composite powder was successfully obtained by mechanical alloying of AlSi₅Cu₂ chips with reinforcement of 0, 10, 15, 20 wt. % of silicon carbide. X-ray powder diffraction was used to characterize obtained material. Detailed analyses using transmission and scanning electron microscopy have been conducted in order to collaborate the grain size measurement determined from the XRD analyses. Powders produced in a planetary ball mill with milling time: 1, 5, 10, 15, 20 and 40 hours, have shown shape and size evaluation during mechanical alloying process. It can be seen tendency to decrease the size of the grain as the milling time is increased. It is also noted that the grains of composites (AlSi₅Cu₂/SiC) are smaller than samples prepares without SiC addition. 40 hours of milling lead to formed very small grains of Al phase (20 nm in average) in composite powder.