Fabrication and Microstructure of the Fe3Al/Al2O3 Composites by Pressureless Sintering

Fe(3)Al/Al(2)O(3) composites were fabricated by pressureless sintering in this research. Fe(3)Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment. The Fe(3)Al powders and Al(2)O(3) powders were mixed together, then the Fe(3)Al/Al(2)O(3) composites were fabricated by pressureless sintering process at 1700 degrees C for 2h. The phase composition and microstructure of the Fe(3)Al intermetallics compounds powders and the phase composition and microstructure of the sintered Fe(3)Al/Al(2)O(3) 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 Fe(3)Al intermetallics compounds powders after heat treatment at 800 degrees C and 1000 degrees C. The XRD patterns results showed that there existed Fe(3)Al phase and Al(2)O(3) phase in the sintered composites. The microstructure showed that the mean particles size of the Fe(3)Al intermetallics compounds powders produced by mechanical alloying and heat treatment was rather fine and about 2-3 mu m. The sintered Fe(3)Al/Al(2)O(3) composites exhibited homogenous and compact microstructure, the Fe(3)Al particles were homogenously distributed in the Al(2)O(3) matrix. The mean particles size of Fe(3)Al was about 3-5 mu m. The sintered Fe(3)Al/Al(2)O(3) composites exhibited more homogenous and compact microstructure with the increase of Fe(3)Al content in the Al(2)O(3) matrix.