Effect of high-energy milling on magnesiothermic self-propagating high-temperature synthesis in a mixture of $\mathrm{SiO}_2$, $\mathrm{C}$, and $\mathrm{Mg}$ reactant powders

A mixture of $\mathrm{SiO}_2$, $\mathrm{C}$, and $\mathrm{Mg}$ powders is mechanically milled in a planetary ball mill during different milling times of $60$, $90$, $120$, and $150$ min. The milled powders are then used in a self-propagating high-temperature synthesis (SHS) reaction to produce the $\mathrm{Si}$–$\mathrm{SiC}$ composite. The thermal properties of the milled powders are determined by using differential scanning calorimetry and thermogravimetry. The chemical composition and microstructure of both as-synthesized products and as-leached powders are characterized by the x-ray diffraction analysis and scanning electron microscopy, respectively. The results show that an increase in the milling times of the mixture of the reactant powders has a significant effect on the thermal properties, diffusion processes, and SHS reaction mechanisms, as well as on the phase conversion and the final yield of the products.