Structural evolution in mechanically alloyed Al-Fe powders

Book · Sat Dec 30 23:00:00 EST 1995

OSTI ID:186746

Mukhopadhyay, D K; Suryanarayana, C; Froes, F H ^[1]

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1. Univ. of Idaho, Moscow, ID (United States). Inst. for Materials and Advanced Processes

The structural evolution in mechanically alloyed (MA) binary aluminum-iron powder mixtures containing 1, 4, 7.3, 10.7, and 25 at.% Fe was investigated using x-ray diffraction and electron microscopic techniques. The constitution (number and identify of phases present), microstructure (crystal size, particle size) and transformation behavior of the powders on annealing were studied. The solid solubility of Fe in Al has been extended up to at least 4.5 at.%, which is close to that observed using RS (4.4 at.%), compared to the equilibrium value of 0.025 at.% Fe at room temperature. Nanometer-sized grains were observed in as-milled crystalline powders in all compositions. A fully amorphous phase was obtained in the Al-25 at.% Fe composition, and a mixed amorphous phase plus solid solution of Fe in Al was developed in the Al-10.7 at.% Fe alloy; agreeing well with the predictions made using the semi-empirical Miedema model. Heat treatment of the MA powders containing the supersaturated solid solution or the amorphous phase resulted in the formation of the Al{sub 3}Fe intermetallic in all but the Al-25 at.% Fe powders. In the Al-25 at.% Fe powder, formation of nanocrystalline Al{sub 5}Fe{sub 2} was observed directly by milling.

• OSTI ID: 186746
• Report Number(s): CONF-950201--; ISBN 0-87339-316-3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
AMORPHOUS STATE
CHEMICAL COMPOSITION
EXPERIMENTAL DATA
HEAT TREATMENTS
INTERMETALLIC COMPOUNDS
IRON ALLOYS
LATTICE PARAMETERS
MICROSTRUCTURE
MILLING
PARTICLE SIZE
POWDERS
SCANNING ELECTRON MICROSCOPY
SOLID SOLUTIONS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION