J. Phys. Colloques
Volume 50, Numéro C8, Novembre 198936th International Field Emission Symposium
|Page(s)||C8-401 - C8-406|
J. Phys. Colloques 50 (1989) C8-401-C8-406
ATOM-PROBE STUDY OF SOME FINE-SCALE FEATURES IN NICKEL BASE SUPERALLOYSA. BUCHON, A. BOSTEL et D. BLAVETTE
Laboratoire de Microscopie Ionique, URA CNRS 808, BP. 118, F-76134 Mont Saint Aignan Cedex, France
A single crystal nickel base superalloy (CMSX-2) has been investigated by means of atom-probe techniques. The relationship between applied heat treatments and the composition of both γ and γ' phases are studied. The role of each precipitation sequence in the standard heat treatment (1050°C/16h + 850°C/48h air cool) is discussed. The high spatial resolution of the atom-probe is used for the investigation of the fine scale concentration fluctuations which may occur in the γ-solid solution. The microanalyses exhibit concentration modulations for chromium ; the wavelength is close to 25 Å. The spatial convolution effects of sine-like fluctuations with the analysis area are discussed.