Interfacial reactions in glass/Al-Mg composite fabricated by powder metallurgy process

The interfacial reactions between glass particles and Al-Mg matrix during fabrication by powder metallurgy processes by pressure sintering at 610 °C for 30 min have been studied using scanning electron microscopy (SEM), electron probe and X-ray diffraction. Experimental results show that MgO, MgAl2O4 and Mg2Si are the main reaction compounds produced by the reactions of SiO2(s) + 2Mg(l) → 2MgO(s) + Si(s), 2SiO2(s) + 2Al(s) + Mg(l) → MgAl2O4(s) + 2Si(s) and 2Mg(l) +Si → Mg2Si. The grain boundaries between MgO, MgAl2O4 and Mg2Si are believed to be the diffusion paths (or channels) during the interfacial reactions. The thickness of reaction layer is controlled by the reaction diffusions between O, Mg, Si and Al. Investigation shows that MgAl2O4 is particles shape and MgO and Mg2Si shows samdwich in SiO2 particles, and Mg2Si is still formed in Al-Mg matrix with particles form.