Resolving the morphology of niobium carbonitride nano-precipitates in steel using atom probe tomography

Andrew J Breen; Kelvin Y Xie; Michael P Moody; Baptiste Gault; Hung-Wei Yen; Christopher C Wong; Julie M Cairney; Simon P Ringer

doi:10.1017/S1431927614012872

Resolving the morphology of niobium carbonitride nano-precipitates in steel using atom probe tomography

Microsc Microanal. 2014 Aug;20(4):1100-10. doi: 10.1017/S1431927614012872.

Authors

Andrew J Breen¹, Kelvin Y Xie², Michael P Moody³, Baptiste Gault³, Hung-Wei Yen¹, Christopher C Wong⁴, Julie M Cairney¹, Simon P Ringer¹

Affiliations

¹ 1School of Aerospace,Mechanical and Mechatronic Engineering,The University of Sydney,NSW 2006,Australia.
² 3School of Mechanical Engineering,Johns Hopkins University,Baltimore,MD 21218-2682,USA.
³ 4Department of Materials,University of Oxford,Parks Road,OX13PH,Oxford,UK.
⁴ 5Department of Psychology,The University of Sydney,NSW 2006,Australia.

PMID: 25410602
DOI: 10.1017/S1431927614012872

Abstract

Atom probe is a powerful technique for studying the composition of nano-precipitates, but their morphology within the reconstructed data is distorted due to the so-called local magnification effect. A new technique has been developed to mitigate this limitation by characterizing the distribution of the surrounding matrix atoms, rather than those contained within the nano-precipitates themselves. A comprehensive chemical analysis enables further information on size and chemistry to be obtained. The method enables new insight into the morphology and chemistry of niobium carbonitride nano-precipitates within ferrite for a series of Nb-microalloyed ultra-thin cast strip steels. The results are supported by complementary high-resolution transmission electron microscopy.