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]
- 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), Vol. 29:6; ISSN 0956-716X
- Country of Publication:
- United States
- Language:
- English
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