Measurements of sonic velocity

Schematic of sonic apparatus for measurhuj orientation (after Moseley.  

Because the pulse frequency is very high ( 10 kHz), one can utilise the method as an on-line system to monitor orientation induced during fibre processing operations such as fibre drawing, spinning, etc. Generally the technique is applied in conjunction with other methods. For example, in Fig. 49 data of Charch and Moseley are given on a drawn Nylon 66 fibre. Note that X-ray diffraction as well as sonic velocity data have been combined with the stress strain behaviour of the filaments. 

In conclusion the usefulness of the sonic technique has found merit when applied to uniaxially deformed materials that can be fabricated to give rodlike geometry. It seems that its application to biaxially deformed material, however, hardly has desirability, particularly if one is attempting to determine planar orientation. 

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