Mechanical properties of cerium and a cerium-5 wt% lanthanum alloy by nanoindentation and ultrasonic velocity measurements

D. W. Wheeler, J. Zekonyte, R. J. K. Wood

    Research output: Contribution to journalArticlepeer-review

    Abstract

    This paper describes a study of the mechanical properties of cerium (Ce) and a cerium–5 wt% lanthanum (Ce–5 wt% La) alloy using nanoindentation and ultrasonic velocity measurements. The materials were also characterised using optical microscopy, energy dispersive spectroscopy, Raman spectroscopy and X-ray diffraction. Despite their propensity to oxidise rapidly in air, both unalloyed Ce and the Ce–5 wt% La alloy have been studied safely in an open laboratory. The hardness and elastic modulus values of the Ce–5 wt% La alloy were slightly higher than those of unalloyed Ce. However, the hardness values of both materials were significantly higher than other values reported in the literature; this was attributed to the presence of cerium oxide inclusions in the microstructure. Reasonable agreement was found between the elastic moduli obtained by nanoindentation and ultrasonic velocity measurements. The mean elastic modulus measured by nanoindentation was, on average, 14% higher than that obtained from the ultrasonic velocity measurements. This work has demonstrated that, with care, Ce can be handled in an open laboratory and meaningful mechanical property data obtained that appear to be free of the influence of the surface oxide layer.
    Original languageEnglish
    Pages (from-to)294-302
    JournalMaterials Science and Engineering: A
    Volume578
    Early online date1 May 2013
    DOIs
    Publication statusPublished - 20 Aug 2013

    Keywords

    • Cerium
    • Nanoindentation
    • Oxidation
    • Rare earth alloys
    • X-ray diffraction

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