Mechanical properties of tungsten copper composites: direct measurement by neutron diffraction

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Date
2014-02-04
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Publisher
Australian Institute of Physics
Abstract
The composite W-10 wt%Cu (19.35% by volume, assuming negligible porosity) has been studied using the ENGIN-X beamline at the ISIS pulsed neutron source at the Rutherford Appleton Laboratory. An as-machined, compression sample was initially measured in order to check for the presence of residual stresses in the composite, using a mixed powder sample of the same elemental weight fractions as the “zero stress” comparison. Then a series of mechanical tests were carried out on the composite for applied compressive loads up to 250 MPa at both room temperature and 100ºC and compared with similar tests carried out on pure tungsten and copper samples. Residual stress values of -280 MPa (for the tungsten matrix) and 480 MPa (for the copper particulate phase) were measured for the as-machined sample. This is a surprising result, given that the yield stress for copper is typically less than 100 MPa but is not inconsistent with residual stresses reported in the literature for W-Cu composites. The mechanical properties for the composite have also been determined from the results of these in-situ, mechanical tests and compared with finite element calculations based on microstructural models for the composite material.
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Keywords
Coherent scattering, Diffraction, Elements, Evaluation, Materials, Mechanical properties, Metals, Refractory metals, Scattering, Stresses, Transition elements
Citation
Mignone, P. J., Finlayson, T. R., Kabra, S., Zhang, S.-Y., Franks, G. V., & Riley, D. P. (2014). Mechanical properties of tungsten copper composites: direct measurement by neutron diffraction. Poster presented to the 38th Annual Condensed Matter and Materials Meeting 2014, Waiheke Island Resort, Waiheke, Auckland, New Zealand 4th February - 7th February, 2014. Retrieved from: https://physics.org.au/wp-content/uploads/cmm/2014/Wagga2014proceedings.pdf