J. Phys. Colloques
Volume 49, Numéro C6, Novembre 198835th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ
|Page(s)||C6-323 - C6-327|
J. Phys. Colloques 49 (1988) C6-323-C6-327
PREFERENTIAL FIELD EVAPORATION DURING ATOM PROBE ANALYSIS OF ZIRCALOY-4B. WADMAN, H.-O. ANDRÉN et U. ROLANDER
Department of Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden
Previous experiments using atom probe analysis to determine the matrix composition of Zircaloy-4, a zirconium alloy used for nuclear fuel tubes in pressurised water reactors, showed a higher Sn concentration in some analysis, compared to the chemical analysis of the materials studied. This effect had no evident metallurgical explanation, and was considered to depend on preferential field evaporation of zirconium. A study has been performed in order to reduce the loss of zirconium between pulses. By varying the conditions of analysis, i.e., temperature and pulse fraction, it was found that the correct values for the matrix composition were obtained using a temperature of 60 K and a pulse fraction of 15 percent of the holding field.