Fabrication and Microstructure of the Fe3Al/Al2O3 Composites by Pressureless Sintering
Fe3Al/Al2O3 composites were fabricated by pressureless sintering in this research. Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment. The Fe3Al powders and Al2O3 powders were mixed together, then the Fe3Al/Al2O3 composites were fabricated by pressureless sintering process at 1700oC for 2h. The phase composition and microstructure of the Fe3Al intermetallics compounds powders and the phase composition and microstructure of the sintered Fe3Al/Al2O3 composites were investigated. The XRD patterns results showed that the Fe-Al intermetallics compounds powders were prepared by mechanical alloying for 60h, and the Fe-Al intermetallics compounds powders transformed into Fe3Al intermetallics compounds powders after heat treatment at 800oC and 1000oC. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The microstructure showed that the mean particles size of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment was rather fine and about 2-3μm. The sintered Fe3Al/Al2O3 composites exhibited homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix. The mean particles size of Fe3Al was about 3-5μm. The sintered Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix.