Investigation of Microstructure and Property of the Fe_3Al/Al_2O_3 Composites Fabricated by Mechanical Alloying Process and Plasma Active Sintering Process

摘要

The Fe_3Al/Al_2O_3 composites were fabricated by plasma active sintering process. The Fe_3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe_3Al powders and Al_2O_3 powders were mixed and the Fe_3Al/Al_2O_3 composite powders were prepared, so the Fe_3Al/Al_2O_3 composites were fabricated by plasma active sintering process at 1200°C for 5min under the pressure of 30MPa. The phase composition and microstructure of the Fe_3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical property of the Fe_3Al/Al_2O_3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe_3Al phase and Al_2O_3 phase in the sintered composites. The FeaAl/Al_2O_3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe_3Al particles were homogenously distributed in the Al_2O_3 matrix. The mean particles size of Fe_3Al intermetallics was about 2-3um and mean particles sizes of Al_2O_3 was about 2-3 μm. The density and relative density of the Fe_3Al/Al_2O_3 composites increased gradually with the increase of Fe_3Al content. The fracture strength and fracture toughness of the Fe_3Al/Al_2O_3 composites increased gradually with the increase of Fe_3Al content. The elastic modulus and hardness(HRA) of Fe_3Al/Al_2O_3 composites decreased gradually with the increase of Fe_3Al content.