Characterization of Al[sub 2]Ti precipitates in cubic Al[sub 64. 5]Ti[sub 27. 5]Cr[sub 8]

Journal Article · Sat May 15 04:00:00 EDT 1993 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(93)90471-4· OSTI ID:6614675

Wright, R N; Erickson, A E; O'Brien, M H; Rabin, B H ^[1]

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1. Idaho National Engineering Lab., Idaho Falls (United States)

Alloys based on Al[sub 3]Ti are attracting increasing interest for elevated temperature structural applications because of their anticipated elevated temperature strength, along with their low density and excellent oxidation resistance. Binary Al[sub 3]Ti has an ordered tetragonal crystal structure that relaxes to the cubic L1[sub 2] structure with the addition of ternary elements. Close control of the alloy composition is important to produce single phase material with the L1[sub 2] structure. For stoichiometric Ti content alloys containing Cr, a minimum of 7 at.% Cr is necessary to produce single phase cubic material, while additions of greater than 13% Cr result in the formation of Cr-rich phases in addition to the L1[sub 2] phase. Control of the Ti concentration is also important; for ternary alloys containing Cr, Mn or Cu, compositions exceeding 27 at.% Ti have been shown to exhibit very fine precipitates of Al[sub 2]Ti, which can also result in an increase in hardness. In binary material, it has recently been reported that Al[sub 2]Ti is stable up to the liquidus temperature. While Al[sub 2]Ti has been observed in several Ti-rich cubic Al[sub 3]Ti alloys, the temperature range of stability and coarsening behavior has only been described for a Cu modified alloy. In this paper, the results of characterization studies involving the precipitation of Al[sub 2]Ti in a cubic Al[sub 64.5]Ti[sub 27.5]Cr[sub 8] alloy are reported, along with preliminary results of age hardening experiments.

• OSTI ID: 6614675
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 28:10; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
AGE HARDENING
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
CHROMIUM ALLOYS
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
HARDENING
INFORMATION
MICROSTRUCTURE
NUMERICAL DATA
PRECIPITATION
SEPARATION PROCESSES
STOICHIOMETRY
TITANIUM ALLOYS