ORDER AND DISSOCIATION IN /cap alpha/-IRON-BERYLLIUM ALLOYS

Journal Article · Sun Sep 01 04:00:00 EDT 1963 · Acta Met.

DOI:https://doi.org/10.1016/0001-6160(63)90208-6· OSTI ID:4624738

Heimendahl, M v; Heubner, U

Iron alloys with 12.9, 21.0, and 29.4 at.% Be were homogenized at 1170 deg C and quenched in water to room temperature. In subsequent precipitation of the 29.4% alloy at temperatures under 520 deg C, the unordered alpha -mixed crysials were transformed into ordered alpha '-mixed crystals with the same chemical composition. The order state is of the Fe-- Al type and is metastable. With prolonged precipitation it decays into a disordered stable phase poor in Be. Precipitation of the 21.0% alloy produces a Be-poor metastable alpha -phase and a Be-rich ordered alpha '-phase. The dissocinted alpha and alpha ' phases lie plate-like side by side in the same orientation. A lattice modulation is present in the (100) direction. The wavelengths of the lattice modulation show a linear increase with the length of precipitation. An activation energy of 58 kcal/mol was determined. Alloys with 12.9% dissociate metastably in the same manner as the 21.0% alloys. The iron-rich side of the phase dingram is shown. (J.S.R.)

• Research Organization: Institut fur Metallkunde der Bergakademie Clausthal, Deutschland, Ger.
• NSA Number: NSA-17-039550
• OSTI ID: 4624738
• Journal Information: Acta Met., Journal Name: Acta Met. Vol. Vol: 11
• Country of Publication: Country unknown/Code not available
• Language: German

Related Subjects

ALLOTROPY
BERYLLIUM ALLOYS
DECOMPOSITION
HEAT TREATMENTS
IRON ALLOYS
LATTICES
METALS, CERAMICS, AND OTHER MATERIALS
PHASE DIAGRAMS
PRECIPITATION
QUENCHING
STABILITY