2008 Volume 49 Issue 2 Pages 304-309
To improve the mechanical properties of magnesium alloys, hot pressing was performed to produce a silicon carbide-dispersion-strengthened magnesium (SiCp/Mg), in which SiC particles (SiCp) were milled with pure Mg using an attritor ball mill to reinforce the Mg. In this study, the silicon carbide dispersion strengthening of magnesium using the mechanical alloying (MA) method was investigated. The experimental results are summarized as follows. By increasing the milling energy of the ball mill in which the pAl2O3/Mg MA powder of a previous study was fabricated, the density of the SiCp/Mg was able to be increased to a value higher than that of the pAl2O3/Mg. The SiCp/Mg is about two-thirds as dense as commercial aluminum alloys. The hardness of the SiCp/Mg was about 1.5-fold that of the pAl2O3/Mg and exceeded that of AZ91D, which has the best mechanical properties of all the commercial Mg alloys. The highest value obtained was 95 HV. The bending strength of the SiCp/Mg was better than that of the pAl2O3/Mg. The results of XRD analysis and SEM-EDAX of the SiCp/Mg suggest that SiCp is almost uniformly and finely dispersed in the Mg and that the grain size of the matrix becomes finer with the dispersion.