J. Phys. Colloques
Volume 50, Numéro C8, Novembre 198936th International Field Emission Symposium
|Page(s)||C8-395 - C8-400|
J. Phys. Colloques 50 (1989) C8-395-C8-400
APFIM/TEM CHARACTERIZATION OF PRECIPITATION IN ALLOY 718M.G. BURKE1 et M.K. MILLER2
1 Westinghouse Science and Technology Center, Pittsburgh PA 15235, U.S.A.
2 Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge TN 37831-6376, U.S.A.
The combined techniques of atom probe field-ion microscopy and transmission electron microscopy have been used to characterize the microstructure of Alloy 718, a γ'' and γ' strengthened nickel-base superalloy. The effect of heat treatment on precipitation has been studied. The morphology, crystal structure, and distribution of the phases have been identified by transmission electron microscopy and the chemistries of the γ'' and γ' precipitates have been measured with the atom probe. The results show a wide variation in the composition of these precipitates which is dependent upon aging treatment.