### ASA 125th Meeting Ottawa 1993 May

## 1pPA1. Determination of texture coefficients in hexagonal polycrystalline
aggregates with orthorhombic symmetry using ultrasonic waves propagating on one
to three principal planes.

**P. J. Kielczynski
**

**
A. Moreau
**

**
J. F. Bussiere
**

**
**
*Industrial Mater. Inst., Natl. Res. Council of Canada, 75 De Mortagne
Blvd., Boucherville, PQ J4B 6Y4, Canada
*

*
*
A method to characterize the texture of hexagonal polycrystalline
aggregates with orthorhombic macroscopic symmetry is presented. Previous
methods are extended to the analysis of waves propagating on three principal
planes of the material. Five coefficients of the crystallographic orientation
distribution function, W[sub 200], W[sub 220], W[sub 400], W[sub 420], and
W[sub 440], are determined from angular variations of the phase velocity of the
four ultrasonic modes considered: the bulk longitudinal waves, Rayleigh surface
waves, the fundamental symmetric plate mode (in the long-wavelength limit), and
shear-horizontal mode. Analytical expressions for the texture coefficients are
found for an arbitrary number of principal planes. Measurements are reported
for a Zr--2.5wt%Nb pressure tube, an alloy used in CANDU nuclear reactors. The
angular variations of the phase velocity of leaky Rayleigh waves and leaky
surface skimming compressional waves are measured with a line-focus acoustic
microscope. The results agreed with neutron scattering measurements.