Laser sintering of magnesia with nanoparticles of iron oxide and aluminum oxide

Highlights: • Laser sintered MgO pellets with nanoparticles of Al₂O₃ and Fe₂O₃. • Characterized these pellets by XRD, SEM and XPS. • Spinel formations were observed in both cases. • Changes in morphology and structure were analyzed. - Abstract: Nanoparticles of iron oxide (Fe₂O₃, 20–40 nm) and aluminum oxide (Al₂O₃, 50 nm) were mixed in different concentrations (3, 5 and 7 wt%) in a magnesium oxide (MgO) matrix. The mixture pellet was irradiated with 532 nm output from a Q-switched Nd:YAG laser using different laser fluence and translation speed for sintering. The refractory samples obtained were analyzed using X-ray diffraction technique, scanning electron microscopy and X-ray photoelectron spectroscopy. The results showed that the samples irradiated at translation speed of 110 μm/s and energy fluence of 1.7 J/cm² with a concentration of 5 and 7 wt% of Fe₂O₃ presented the MgFe₂O₄ spinel-type phase. With the addition of Al₂O₃ nanoparticles, at a translation speed of 110 μm/s and energy fluence of 1.7 J/cm², there were the formations of MgAl₂O₄ spinel phase. The changes in morphologies and microstructure due to laser irradiation were analyzed