Mechanically driven alloying and grain size changes in nanocrystalline Fe-Cu powders

Journal Article · Sun Mar 14 23:00:00 EST 1993 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.353055· OSTI ID:7036593

Eckert, J; Holzer, J C; Krill, III, C E; Johnson, W L ^[1]

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1. California Institute of Technology, W. M. Keck Laboratory of Engineering Materials 138-78, Pasadena, California 91125 (United States)

Highly supersaturated nanocrystalline Fe[sub [ital x]]Cu[sub 100[minus][ital x]] alloys (10[le][ital x][le]95) have been prepared by mechanical alloying of elemental crystalline powders. The development of the microstructure is investigated by x-ray diffraction, differential scanning calorimetry, and transmission electron microscopy. The results are compared with data for ball-milled elemental Fe and Cu powders, samples prepared by inert gas condensation, and sputtered films. The deformation during milling reduces the grain size of the alloys to 6--20 nm. The final grain size of the powders depends on the composition of the material. Single-phase fcc alloys with [ital x][le]60 and single-phase bcc alloys with [ital x][ge]80 are formed even though the Fe-Cu system exhibits vanishingly small solid solubilities under equilibrium conditions. For 60[le][ital x][le]80, fcc and bcc solid solutions coexist. The alloy formation is discussed with respect to the thermodynamic conditions of the material. The role of the large volume fraction of grain boundaries between the nanometer-sized crystals, as well as the influence of internal strains and stored enthalpies introduced by ball milling, is critically assessed.

• DOE Contract Number: FG03-86ER45242
• OSTI ID: 7036593
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 73:6; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
ALLOYS
COHERENT SCATTERING
COPPER ALLOYS
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON MICROSCOPY
GRAIN BOUNDARIES
GRAIN SIZE
IRON ALLOYS
MACHINING
MICROSCOPY
MICROSTRUCTURE
MILLING
POWDERS
SCATTERING
SIZE
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION