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Composition and precipitation inhomogeneities in melt-spun Al-Cu and Al-Zn ribbons

Abstract

Non-uniform distributions of solute content in the supersaturated {alpha} Al matrix and inhomogeneous precipitation of metastable/stable phases have been studied in rapidly solidified Al-Cu and Al-Zn ribbons. Double peaked X-ray diffraction lines from the {alpha} Al matrix were observed in three as-quenched Al-Cu alloys and one annealed Al-Zn alloy. For as-quenched Al-Cu ribbons, variations in composition, microstructure and precipitate density across the ribbons results from local differences in coolingrates. These differences originate from recalescence during the solidification. The double peaked diffraction lines for these alloys corresponds to two compositions of the {alpha} Al phase with less copper solute in the topside than in the wheelside of the ribbons. Subsequently, annealing of the samples leads to inhomogeneous precipitation of the metastable {Theta}` phase across the whole thickness of the ribbons. Such inhomogeneities do not appear in as-quenched Al-Zn alloys which are quenched into a single {alpha} Al phase. Splitting of the diffraction lines in the annealed ribbons arises from differences in the composition of two different {alpha} Al matrix phases. The {alpha} Al phase between the R phase lamellae has low zinc content, while the {alpha} Al phase where high densities of G.P. zones are retained has higher zinc concentration. (orig.).
Publication Date:
Dec 31, 1991
Product Type:
Technical Report
Report Number:
KU-HCOE-FL2-R-91-15
Reference Number:
SCA: 360102; PA: AIX-23:018595; SN: 92000664420
Resource Relation:
Other Information: PBD: 1991
Subject:
36 MATERIALS SCIENCE; ALUMINIUM ALLOYS; MICROSTRUCTURE; COPPER ALLOYS; CRYSTAL STRUCTURE; PRECIPITATION; SOLIDIFICATION; X-RAY DIFFRACTION; ZINC ALLOYS; 360102; STRUCTURE AND PHASE STUDIES
OSTI ID:
10120600
Research Organizations:
Copenhagen Univ. (Denmark). H.C. Oersted Inst.
Country of Origin:
Denmark
Language:
English
Other Identifying Numbers:
Other: ON: DE92617637; TRN: DK92C0002018595
Availability:
OSTI; NTIS (US Sales Only); INIS
Submitting Site:
DKN
Size:
37 p.
Announcement Date:
Jun 30, 2005

Citation Formats

Li, Q, Johnson, E, Johansen, A, and Sarholt-Kristensen, L. Composition and precipitation inhomogeneities in melt-spun Al-Cu and Al-Zn ribbons. Denmark: N. p., 1991. Web.
Li, Q, Johnson, E, Johansen, A, & Sarholt-Kristensen, L. Composition and precipitation inhomogeneities in melt-spun Al-Cu and Al-Zn ribbons. Denmark.
Li, Q, Johnson, E, Johansen, A, and Sarholt-Kristensen, L. 1991. "Composition and precipitation inhomogeneities in melt-spun Al-Cu and Al-Zn ribbons." Denmark.
@misc{etde_10120600,
title = {Composition and precipitation inhomogeneities in melt-spun Al-Cu and Al-Zn ribbons}
author = {Li, Q, Johnson, E, Johansen, A, and Sarholt-Kristensen, L}
abstractNote = {Non-uniform distributions of solute content in the supersaturated {alpha} Al matrix and inhomogeneous precipitation of metastable/stable phases have been studied in rapidly solidified Al-Cu and Al-Zn ribbons. Double peaked X-ray diffraction lines from the {alpha} Al matrix were observed in three as-quenched Al-Cu alloys and one annealed Al-Zn alloy. For as-quenched Al-Cu ribbons, variations in composition, microstructure and precipitate density across the ribbons results from local differences in coolingrates. These differences originate from recalescence during the solidification. The double peaked diffraction lines for these alloys corresponds to two compositions of the {alpha} Al phase with less copper solute in the topside than in the wheelside of the ribbons. Subsequently, annealing of the samples leads to inhomogeneous precipitation of the metastable {Theta}` phase across the whole thickness of the ribbons. Such inhomogeneities do not appear in as-quenched Al-Zn alloys which are quenched into a single {alpha} Al phase. Splitting of the diffraction lines in the annealed ribbons arises from differences in the composition of two different {alpha} Al matrix phases. The {alpha} Al phase between the R phase lamellae has low zinc content, while the {alpha} Al phase where high densities of G.P. zones are retained has higher zinc concentration. (orig.).}
place = {Denmark}
year = {1991}
month = {Dec}
}