Investigation of Microstructure and Mechanical Property of the Fe<sub>3</sub>Al/Al<sub>2</sub>O<sub>3</sub> Composites Fabricated by Mechanical Alloying Process and Hot-Pressing Process

Abstract

The Fe3Al/Al2O3composites were fabricated by hot-pressing process in this research. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3powders were mixed and the Fe3Al/Al2O3composite powders were prepared, so the Fe3Al/Al2O3composites were fabricated by hot-pressing process at 1300°C for 2h under the pressure of 35MPa. The phase composition and microstructure of the Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical properties of the Fe3Al/Al2O3composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3phase in the sintered composites. The Fe3Al/Al2O3composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix, the mean particles size of Fe3Al intermetallics compounds was about 3-4μm. The Fe3Al/Al2O3composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3matrix. The density and relative density of the Fe3Al/Al2O3composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness (HRA) of the Fe3Al/Al2O3composites decreased gradually with the increase of Fe3Al content.