Synthesis of iron aluminide-Al sub 2N sub sub 3 composites by in situ displacement reactions

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 1997-04, Vol.239-240, p.640-646
• Main Authors: Subramanian, R, McKamey, C G, Buck, L R, Schneibel, J H
• Format: Article
• Language: English
• ISSN: 0921-5093

Composites consisting of an iron aluminide matrix with ceramic particle reinforcements, such as alumina, could improve the high temperature strength without compromising the oxidation resistance. In this paper, the feasibility of processing Fe-Al alloy/Al sub 2 O sub 3 composites by an in-situ displacement reaction between Fe-40at.%Al and iron oxide, Fe sub 2 O sub 3 , is investigated. Simple powder metallurgical processing was performed without resorting to any externally applied pressures or deformations during the high temperature processing step. The microstructural features of the composites are rationalized based on results from diffusion couples. Preliminary mechanical properties such as fracture toughness, yield strength and hardness are determined and compared with the values obtained for monolithic iron aluminide- Fe-28at.%Al. Results suggest that a significant improvement in the properties is needed and further avenues for modifications, such as changes in the interface strength and externally applied forces during processing, are suggested.