Microstructure and mechanical properties of Fe minus 40Al+Cr alloys
- Thayer School of Engineering, Dartmouth College, Hanover, NH (US)
In a recent study of DO{sub 3}-structured Fe-28Al + Cr alloys, where the chromium concentration varied between 0 and 6 at.%, it was demonstrated that the chromium additions enhanced the ductility and slightly decreased the yield strength. It was also shown that the chromium additions decreased the anti-phase boundary (APB) energy of the {l angle}111{r angle} dislocations, which made cross-slip easier. In another study of B2-structured iron-rich FeAl alloys it was shown that gliding {l angle}111{r angle} {l brace}110{r brace} dislocations interact during deformation to form {lt}001{gt} edge dislocations. The energetic driving force for the formation of these {l angle}001{r angle} dislocations is the removal of the {l brace}110{r brace} APB energy. It was suggested that these {l angle}001{r angle} dislocations may be the cause of transgranular cleavage in FeAl alloys. In this paper chromium additions of both 5 and 10 at.% were made to Fe-40 Al to try to lower the {l brace}110{r brace} APB energy. The idea was that in reducing the APB energy, the density of {l angle}001{r angle} dislocations would be reduced and hence the ductility may be increased. Microstructural analysis was performed in the As- cast conditions and after several different thermal and mechanical treatments. This paper reports upon the dislocation structures observed, together with a preliminary study of the mechanical properties of these alloys.
- OSTI ID:
- 5660076
- Journal Information:
- Scripta Metallurgica; (United States), Journal Name: Scripta Metallurgica; (United States) Vol. 24:12; ISSN 0036-9748; ISSN SCRMB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
ALUMINIUM ALLOYS
CHROMIUM ADDITIONS
CHROMIUM ALLOYS
CRYSTAL STRUCTURE
DEFORMATION
FABRICATION
HEAT TREATMENTS
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS WORKING
MECHANICAL PROPERTIES
MICROSTRUCTURE
THERMOMECHANICAL TREATMENTS