Alloying effects and microstructure of iron aluminides

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6569321

Horton, J A; Liu, C T; Koch, C C

An alloying study of the iron aluminide, Fe/sub 3/Al, with ternary additions of boron, silicon, copper, or nickel has been performed in order to investigate their alloying behavior and associated microstructures. It was found that additions of boron had virtually no effect on the ductility and fracture behavior of Fe/sub 3/Al. Although silicon and copper increased the yield stress and hardness both elements were found to embrittle the alloy by a process of second phase precipitation. Second-phase particles were observed only on grain boundaries in the silicon alloys with greater than or equal to 3 at. % Si, but these precipitates were almost silicon free. Copper additions resulted in extensive precipitation throughout the matrix and on grain boundaries except for a precipitate-free zone adjacent to the grain boundaries. Nickel additions also resulted in grain boundary fracture in two-phase alloys except for the alloy of the composition 40 at. % Fe-40Ni-20Al. This alloy has improved high-temperature strength as well as room-temperature ductility.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6569321
• Report Number(s): CONF-840417-6; ON: DE85000903
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
BORON ADDITIONS
BORON ALLOYS
COPPER ADDITIONS
COPPER ALLOYS
CRYSTAL STRUCTURE
EMBRITTLEMENT
FAILURES
FRACTURES
GRAIN BOUNDARIES
INTERMETALLIC COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
SILICON ADDITIONS
SILICON ALLOYS