Effect of cooling and annealing on the phase composition of a nickel-base superalloy. [66. 7 Ni, 12. 0 Al, 2. 8 Ti. 0. 9 Ta, 9. 6 Cr, 5. 0 Co, 3. 0 W]

Journal Article · Wed Sep 01 04:00:00 UTC 1993 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(93)90242-K· OSTI ID:5989318

Schmidt, R; Feller-Kniepmeier, M ^[1]

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1. Technische Univ. Berlin (Germany). Inst. fuer Metallforschung

Concentration gradients of the elements near the [gamma]/[gamma][prime]-interface, as well as in the volume of the precipitates are believed to influence the mechanical behavior of [gamma][prime]-strengthened superalloys. In this paper the effect of cooling rates and annealing on the elemental profiles near the phase boundary and within the precipitates of the single crystal superalloy SRR 99 is demonstrated. It is shown that the observed concentration profiles can be explained by the temperature dependent solubility, the different diffusion rates of elements, and by the shift of the [gamma]/[gamma][prime] interfaces during cooling or Ostwald ripening. On the basis of the chromium distribution within the [gamma][prime]-phase the evolution of the precipitates can be divided into four stages: (1) nucleation, (2) growth, (3) homogenization and (4) Ostwald ripening.

• OSTI ID: 5989318
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 29:6; ISSN 0956-716X; ISSN SCRMEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
ALLOYS
ALUMINIUM ALLOYS
ANNEALING
CHROMIUM ALLOYS
COBALT ALLOYS
COOLING
HEAT TREATMENTS
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
TANTALUM ADDITIONS
TANTALUM ALLOYS
TITANIUM ALLOYS
TUNGSTEN ALLOYS