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Volume 6
Research & Reviews: Journal of Material Sciences
ISSN: 2321-6212
Magnetic Materials 2018
October 22-23, 2018
October 22-23, 2018 | Rome, Italy
3
rd
International Conference on
Magnetism and Magnetic Materials
Res. Rev. J Mat. Sci. 2018, Volume 6
DOI: 10.4172/2321-6212-C6-030
Direct volumetric measurement of crystallographic texture using acoustic waves
Bo Lan
Imperial College London, UK
C
rystallographic texture (i.e. preferred orientation distribution) in polycrystals has profound effects on a range of physical
properties (e.g. elasticity, plasticity, magnetism and thermal expansion hence is of great industrial importance. However,
cost-effective, lab-based, non-destructive measurement of bulk texture has been elusive for the existing texture measurement
techniques, such as EBSD, X-ray or neutron diffraction. This talk gives an overview of the efforts towards enabling such
capabilities using ultrasound. These developments are based on a general theoretical platform developed by the speaker, which
demonstrates that the 3Dwave speeds in a polycrystals could be approximated as a simple spherical convolution between texture
and single crystal speeds, thus enabling generic inverse texture extraction. Two independent experimental implementations of
the theories have been achieved: one is based on the conventional water-bath ultrasonic system, where the directional variations
of polycrystals wave speeds are directly measured, to be input to the de-convolution model for texture; and the other employs
the resonant ultrasound spectroscopy to measure elastic constants from a regular-shaped sample’s natural frequencies, and
the wave speeds are calculated from the measured elasticity. Both techniques have been used to examine a range of industrial
metals, including titanium, zirconium, and stainless steels, with the results successfully verified against the well-established
neutron diffraction. Utilization of such texture information, e.g. to predict macroscopic properties, is also explored.
bo.lan@imperial.ac.uk