Ultrasonic measurement of the kearns texture factors in zircaloy, zirconium, and titanium

Texture, developed during the processing of zirconium and zirconium alloys, e.g., ZIRCALOY, plays an important role in determining the properties and performance of the resultant structural components. Extending the work done on cubic metals, ultrasonic velocity measurements were used to nondestructively characterize the texture in hexagonal sheet metals. A theory is developed relating the texture coefficients W _LMN (L≤4, found in an expansion of the crystallite orientation distribution function (ODF) in terms of generalized spherical harmonics) to industrially measured Kearns factors, which predict the fraction of basal poles aligned in a particular sample reference direction. Ultrasonic characterization of texture has been performed on three sheets of zirconium (one pure, two ZIRCALOY) and on one sheet of titanium. These results are compared to the Kearns factors, measured by X-ray diffraction (for the two ZIRCALOY sheets) and to the W _LMN value measured by neutron diffraction (for the pure zirconium and the titanium). Results show that ultrasonics predict both the orientation distribution coefficients (ODCs) and the Kearns factors very well.