Quantitative atom probe analysis of carbides
Journal article, 2011

Compared to atom probe analysis of metallic materials, the analysis of carbide phases results in an enhanced formation of molecular ions and multiple events. In addition, many multiple events appear to consist of two or more ions originating from adjacent sites in the material. Due to limitations of the ion detectors measurements generally underestimate the carbon concentration. Analyses using laser-pulsed atom probe tomography have been performed on SiC, WC, Ti(C,N) and Ti 2 AlC grains in different materials as well as on large M 2 3C 6 precipitates in steel. Using standard evaluation methods, the obtained carbon concentration was 6-24% lower than expected from the known stoichiometry. The results improved remarkably by using only the 13 C isotope, and calculating the concentration of 12 C from the natural isotope abundance. This confirms that the main reason for obtaining a too low carbon concentration is the dead time of the detector, mainly affecting carbon since it is more frequently evaporated as multiple ions. In the case of Ti(C,N) andTi 2 AlC an additional difficulty arises from the overlap between C 2 + ,C 2+ 4 and Ti 2+ at the mass-to-charge 24 Da. © 2010 Elsevier B.V.

Author

Mattias Thuvander

Chalmers, Applied Physics, Microscopy and Microanalysis

Jonathan Weidow

Chalmers, Applied Physics, Microscopy and Microanalysis

Jenny Angseryd

Chalmers, Applied Physics, Microscopy and Microanalysis

Lena Falk

Chalmers, Applied Physics, Microscopy and Microanalysis

Fang Liu

Chalmers, Applied Physics, Microscopy and Microanalysis

Marie Sonestedt

Chalmers, Applied Physics, Microscopy and Microanalysis

Krystyna Marta Stiller

Chalmers, Applied Physics, Microscopy and Microanalysis

Hans-Olof Andrén

Chalmers, Applied Physics, Microscopy and Microanalysis

Ultramicroscopy

0304-3991 (ISSN)

Vol. 111 6 604-608

Subject Categories

Analytical Chemistry

Other Materials Engineering

Areas of Advance

Materials Science

DOI

10.1016/j.ultramic.2010.12.024

More information

Created

10/7/2017