Browsing by Author "Cuiuri, D"

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    Diffraction line profile analysis of 3D wedge samples of Ti-6Al-4V fabricated using four different additive manufacturing processes
    (MDPI, 2019-01-09) Cottam, R; Palanisamy, S; Avdeev, M; Jarvis, T; Henry, C; Cuiuri, D; Balogh, L; Abdul Rahman Rashid, R
    Wedge-shaped samples were manufactured by four different Additive Manufacturing (AM) processes, namely selective laser melting (SLM), electron beam melting (EBM), direct metal deposition (DMD), and wire and arc additive manufacturing (WAAM), using Ti-6Al-4V as the feed material. A high-resolution powder diffractometer was used to measure the diffraction patterns of the samples whilst rotated about two axes to collect detected neutrons from all possible lattice planes. The diffraction pattern of a LaB6 standard powder sample was also measured to characterize the instrumental broadening and peak shapes necessary for the Diffraction Line Profile Analysis. The line profile analysis was conducted using the extended Convolution Multiple Whole Profile (eCMWP) procedure. Once analyzed, it was found that there was significant variation in the dislocation densities between the SLMed and the EBMed samples, although having a similar manufacturing technique. While the samples fabricated via WAAM and the DMD processes showed almost similar dislocation densities, they were, however, different in comparison to the other two AM processes, as expected. The hexagonal (HCP) crystal structure of the predominant α-Ti phase allowed a breakdown of the percentage of the Burgers’ vectors possible for this crystal structure. All four techniques exhibited different combinations of the three possible Burgers’ vectors, and these differences were attributed to the variation in the cooling rates experienced by the parts fabricated using these AM processes. © This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
  • No Thumbnail Available
    Item
    Investigation of residual stresses in titanium aerospace components formed via additive manufacturing
    (Engineers Australia, 2014-01-01) Hoye, N; Li, HJ; Cuiuri, D; Paradowska, AM; Thorogood, KJ
    In the present study gas tungsten arc welding (GTAW) with automated wire addition was used to additively manufacture (AM) a representative thin-walled aerospace component from Ti-6Al-4V in a layer-wise manner. Residual strains, and hence stresses, were analysed quantitatively using neutron diffraction techniques on the KOWARI strain scanner at the OPAL research facility operated by the Australian Nuclear Science and Technology Organisation (ANSTO). Results showed that residual strains within such an AM sample could be measured with relative ease using the neutron diffraction method. Residual stress levels were found to be greatest in the longitudinal direction and concentrated at the interface between the base plate and deposited wall. Difficulties in measurement of lattice strains in some discrete locations within the deposited material were ascribed to the formation of localised grain orientation where α-Ti laths form in aligned colonies within prior β-Ti grain boundaries upon cooling. Neutron diffraction measurements of residual stress were cross-correlated using the contour method with results found to be in close agreement. Observations of microstructure reveal 'basket-weave' morphology typical of fusion welds in Ti-6Al-4V. Microhardness measurements show lower hardness in the deposited material compared to the base plate and a further small decrease in hardness in the top region of the deposit, indicating a dependence on thermal cycling from sequential weld deposition. © 2021 Informit
  • No Thumbnail Available
    Item
    Measurement of residual stresses in titanium aerospace components formed via additive manufacturing
    (Trans Tech Publications Ltd, 2014-02) Hoye, N; Li, HJ; Cuiuri, D; Paradowska, AM
    In the present study gas tungsten arc welding (GTAW) with automated wire addition was used to additively manufacture (AM) a representative thin-walled aerospace component from Ti-6Al-4V in a layer-wise manner. Residual strains, and hence stresses, were analysed quantitatively using neutron diffraction techniques on the KOWARI strain scanner at the OPAL research facility operated by the Australian Nuclear Science and Technology Organisation (ANSTO). Results showed that residual strains within such an AM sample could be measured with relative ease using the neutron diffraction method. Residual stress levels were found to be greatest in the longitudinal direction and concentrated at the interface between the base plate and deposited wall. Difficulties in measurement of lattice strains in some discrete locations were ascribed to the formation of the formation of localised texturing where α-Ti laths form in aligned colonies within prior β-Ti grain boundaries upon cooling. Observations of microstructure reveal basket-weave morphology typical of welds in Ti-6Al-4V. Microhardness measurements show a drop in hardness in the top region of the deposit, indicating a dependence on thermal cycling from sequential welds. © 2014, Trans Tech Publications.
  • No Thumbnail Available
    Item
    Neutron diffraction residual stress determinations on Intermetallic alloy components produced by wire-arc additive manufacturing (WAAM)
    (Elsevier, 2019-10-01) Shen, C; Reid, M; Liss, KD; Pan, ZX; Ma, Y; Cuiuri, D; van Duin, S; Li, HJ
    The Wire-Arc Additive Manufacturing (WAAM) process is an increasingly attractive method for producing porosity-free metal components. However, the residual stresses and distortions resulting from the WAAM process are major concerns as they not only influence the part tolerance but can also cause premature failure in the final component during service. The current paper presents a method for using neutron diffraction to measure residual stresses in Fe3Al intermetallic wall components that have been in-situ additively fabricated using the WAAM process with different post-production treatments. By using averaging methods during the experimental setup and data processing, more reliable residual stress results are obtained from the acquired neutron diffraction data. In addition, the present study indicates that the normal residual stresses are significant compared to normal butt/fillet welding samples, which is caused by the large temperature gradient in this direction during the additive layer depositions. © 2019 Elsevier B.V.
  • Thumbnail Image
    Item
    Residual stresses in titanium aerospace components formed via additive manufacture
    (Australian Institute of Nuclear Science and Engineering (AINSE), 2013-12-02) Hoye, N; Li, H; Cuiuri, D; Paradowska, AM
    Additive manufacturing (AM) using arc-wire based metal deposition has been suggested as one method to reduce the costs associated with production of titanium components, particularly within the aerospace sector. In the present study gas tungsten arc welding (GTAW) with automated wire addition was used to additively manufacture (AM) a representative thin-walled aerospace component from Ti-6AI-4V in a layer-wise manner. Residual strains, and hence stresses, were analysed quantitatively using neutron diffraction techniques on the KOWARI strain scanner at the OPAL research facility operated by the Australian Nuclear Science and Technology Organisation (ANSTO). Results showed that residual strains within such an AM sample could be measured with relative ease using the neutron diffraction method. Residual stress levels were found to be greatest in the longitudinal direction and concentrated at the interface between the base plate and deposited wall. Difficulties in measurement of lattice strains in some discrete locations were ascribed to the formation of the formation of localised texturing where α-Ti laths form in aligned colonies within prior β-Ti grain boundaries upon cooling. Observations of microstructure reveal 'basket-weave' morphology typical of welds in Ti-6AI-4V. Microhardness measurements show a drop in hardness in the top region of the deposit, indicating a dependence on thermal cycling from sequential welds. Time-of-flight neutron diffraction has been proposed to analyse stresses in both the α-Ti and β-Ti phases simultaneously as well as inter-granular strains. This study forms part of a wider investigation into the suitability of arc-wire based deposition techniques for the additive manufacture of titanium components.