Oral Presentation 26th ACMM “2020 Visions in Microscopy”

Atom probe crystallography study of additively manufactured Inconel-738 (#35)

Andrew Breen 1 2 , Bryan Lim 1 2 , Hansheng Chen 1 2 , William Davids 1 2 , Xiaozhou Liao 2 , Sophie Primig 3 , Sudarsanam Suresh Babu 4 5 , Simon Ringer 1 2
  1. The Australian Centre for MIcroscopy and Microanalysis, The University of Sydney, Sydney, NSW, Australia
  2. School of Aerospace, Mechanical & Mechatronic Engineering, The University of Sydney, NSW, Australia
  3. School of Materials Science & Engineering, The University of NSW, Sydney, NSW, Australia
  4. Department of Mechanical, Aerospace, and Biomedical Engineering, University of Tennessee, Knoxville, TN, USA
  5. Manufacturing Demonstration Facility, Oak Ridge National Lab, Knoxville, TN, USA

Atom probe tomography (APT) is a powerful analytical tool for characterising the nanostructure and chemistry of engineering materials. The spatial resolution of APT is dependent on the material properties of the specimen being analysed and experimental parameter selection but it is often sufficient to directly resolve lattice structure in crystalline materials [1]. This information is particularly useful for the purposes of reconstruction calibration [2] and direct crystallographic measurements within the analysed specimen [3]. However, crystallographic information in APT data often goes under-utilised due to a lack of appropriate analysis tools and technical know-how among users.  

In this presentation, the latest APT crystallographic analysis techniques will be applied to the case study of electron beam additively manufactured Inconel-738. APT is being used to help understand how the complex thermal cycles a component is subjected to during a build influences the resulting nanostructure and the application of crystallographic analysis tools is key to extracting the best quality information from the acquired data. Approaches to help detect low-signal crystallographic information such as ‘species-specific’ spatial distribution maps (SDMs) [4] and crystallographic mapping techniques [5] will be showcased. The ability for APT do detect ordering in the gamma-prime phase and approaches on how to quantify sub-lattice occupancy of the solute species will also be shown. The advantages of doing ‘mixed-mode’ APT experiments; whereby a single APT tip is subjected to multiple running conditions to combine the best results for both structural and chemical information will be demonstrated.

  1. F. Vurpillot, G. Da Costa, A. Menand, D. Blavette, Structural analyses in three-dimensional atom probe: A Fourier transform approach, Journal of Microscopy, 203 (2001) 295-302.
  2. A.J. Breen, M.P. Moody, A.V. Ceguerra, B. Gault, V.J. Araullo-Peters, S.P. Ringer, Restoring the lattice of Si-based atom probe reconstructions for enhanced information on dopant positioning, Ultramicroscopy, 159 (2015) 314-323.
  3. A.J. Breen, K. Babinsky, A.C. Day, K. Eder, C.J. Oakman, P.W. Trimby, S. Primig, J.M. Cairney, S.P. Ringer, Correlating Atom Probe Crystallographic Measurements with Transmission Kikuchi Diffraction Data, Microscopy and Microanalysis, 23 (2017) 279-290.
  4. K.L. Torres, B. Geiser, M.P. Moody, S.P. Ringer, G.B. Thompson, Field evaporation behavior in 001 FePt thin films, Ultramicroscopy, 111 (2011) 512-517.
  5. N.D. Wallace, A.V. Ceguerra, A.J. Breen, S.P. Ringer, On the retrieval of crystallographic information from atom probe microscopy data via signal mapping from the detector coordinate space, Ultramicroscopy, 189 (2018) 65-75.