J. Phys. Colloques
Volume 49, Numéro C6, Novembre 198835th International Field Emission Symposium / 35éme Symposium International d'Emission de Champ
|Page(s)||C6-299 - C6-304|
J. Phys. Colloques 49 (1988) C6-299-C6-304
ON ATOM-PROBE ANALYSIS OF CUBIC MX-TYPE CARBIDES AND CARBONITRIDESU. ROLANDER et H.-O. ANDRÉN
Department of Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden
The field evaporation behaviour of cubic MX-type carbides and carbonitrides have been investigated using four (Ti,W)(C,N)-2 vol% Ni test alloys with well known compositions. Preferential field evaporation of titanium and nitrogen may occur when the analyses are done in certain crystallographic directions. The reproducibility of the analyses is not very good and this is mainly due to the very high tendency of the atoms to evaporate in pairs or small clusters. It is shown that as much as 14 % of the total C content and 9 % of the total Ti content is lost due to pair ion formation. Since there is no simple way to correct for these losses the instrument must be modified so that either the detector dead time or the mass resolution is decreased.