A Self-propagating high-temperature synthesis process for the fabrication of Fe(Cr)–Al₂O₃ nanocomposite

Self-propagating high-temperature synthesis (SHS) was used to fabricate a Fe(Cr)-Al₂O₃ nanocomposite. The composite was fabricated by the reactions between the powders of Fe, Fe₂O₃, Cr₂O₃, and Al. The effect of blending ratio and mechanical activation of the initial powders and the precursor compressing pressure on the microstructure of the final product was studied by optical microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The significance of the effect of each of the aforementioned parameters on the quality of the composite (assessed by measuring the compressive strength and wear resistance) was determined using a full-factorial design of experiments method. The results showed that the best molar powder ratio that produced the most homogeneous product through a sustainable SHS reaction was Fe:Fe₂O₃:Cr₂O₃:Al = 10:1:1:4. A lower Fe content caused the Fe(Cr) phase to melt and separate from the rest of the materials.