Bestimmung des Kohlenstoff- und Stickstoffgehaltes von Carbo-Nitriden in einer Nickel-Basis Superlegierung
Zusammenfassung der Projektergebnisse
Nickel-base superalloys are meant for applications at high temperatures in hostile atmospheres. Their superior strength derives primarily from nano-scale precipitates of the γ’-phase, whose composition is approximately Ni3(Al, Ti). However, also carbide particles contribute to the high strength of these materials. It is a question of long standing whether and to what extent nitrogen replaces part of the carbon content of the carbide particles. The aim of the present investigation was to determine this nitrogen content by electron energy loss spectroscopy (EELS). The commercial γ’-strengthened nickel-base superalloy NIMONIC PE16 served as an example for the whole class of γ’-strengthened nickel-base superalloys. (Ti, Mo)C-carbide particles were studied. The result is: their nitrogen content is below, probably much below 3.5 at.%. As an alternative method also energy dispersive X-ray (EDX) analysis was applied to determine the nitrogen content of the quoted carbides particles. As to be expected the detection limit of nitrogen in these carbide particles was higher for EDX than for EELS, i. e. the results of the latter method are more reliable. In addition the chemical composition of these carbide particles has been determined by EDX as: 54.7 ± 4.7 at.% C, 29.5 ±1.6 at.% Ti, and 15.8 ± 1.9 at.% Mo.
Projektbezogene Publikationen (Auswahl)
- Frühjahrstagung 2012 der Deutschen Physikalischen Gesellschaft in Berlin: “Analysis of the nitrogen content of carbide particles in a γ ’-strengthened nickel-base superalloy”
M. Peterlechner, P. Hess, M. MacKenzie, H. Rösner und E. Nembach
