Averaging Techniques and Ultrasonic Pole Figures

There is considerable interest in the evaluation of texture via ultrasonic measurements because of the advantages when compared to evaluation by diffraction techniques. First, ultrasonic measurements are much more rapid and have the potential of being used concurrently while processing. Second, ultrasonic measurements are nondestructive while diffraction techniques require coupons to be cut for samples. Third, ultrasonic measurements, like neutron diffraction, sample the bulk of the test material while, in contrast, x-ray diffraction samples a thin surface layer. The primary disadvantage of ultrasonic measurements is that the textural evaluation must be based on a quite limited amount of data whereas diffraction evaluation is normally based upon a very extensive number of measured points. In spite of this disadvantage, research has shown that ultrasonic measurements are potentially useful. Specifically, it has been established [1,2] that during ultrasonic measurements the textural contribution can be distinguished from stress contribution, and it has been shown [3–10] that ultrasonic measurements do give a measure of the type and amount of texture in metal sheet or plate