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Title: Coarsening behavior of L1/sub 2/ phase in an Al-Zr-Ti alloy

Journal Article · · Scr. Metall.; (United States)

Aluminum alloys with improved high temperature mechanical properties are of particular interest to aerospace applications because of their low densities and high strength-to-weight ratios, and their resistance to corrosion and oxidation. By analogy with the ..gamma..'-strengthened nickel base superalloys, which remain stable and retain their useful strengths up to 0.73 T/sub m/ (where T/sub m/ is the absolute melting temperature), development of a dispersion strengthened aluminum alloy useful to 425/sup 0/C seems to be an achievable target. Development of such alloys is an active field of research. For stable mechanical behavior, the dispersed phase should resist phase transformation and growth by Ostwald ripening. A basic requirement for resistance to growth of the dispersed phase is low interfacial energy between dispersoid and matrix. Irrespective of the controlling mechanism, reduction in the total interfacial energy governs the growth of the particles. It is of interest to compare the rate of Ostwald ripening of Ll/sub 2/-structured Al/sub 3/(Zr, Ti) with that of Al/sub 3/(Zr,V). Alloys containing 1 vol.% of Al/sub 3/(Zr/sub .75/Ti/sub .25/) were prepared, and the growth of the Ll/sub 2/-structured precipitates during high temperature aging was studied. This paper reports the results.

Research Organization:
National Research Council Canada, Ottawa, Ontario K1A OR6 (CA); Dept. of Materials Science and Engineering, Northwestern Univ., Evanston, IL (US)
OSTI ID:
6259556
Journal Information:
Scr. Metall.; (United States), Vol. 23:1
Country of Publication:
United States
Language:
English