TABLE OF CONTENTS Microstructural evolution during heat treatment processes has been a subject of research for the past several decades. The knowledge that the material microstructure directly affects the macroscopic material properties was a turning point in the field of materials manufacturing. Specific types of manufacturing processes strive to produce the corresponding microstructure in a controlled fashion. Many heat treatment processes, such as annealing, are used to relieve the internal stress state that develops during cold working, which allows the microstructure to rearrange itself into a state of lower energy. During such processing, individual crystals in a polycrystalline aggregate submit to orientation changes. Often, the recrystallization process creates material texture or preferred orientation of grains. The orientation of the recrystallized grains together with the final grain size distribution determines the final properties of polycrystalline materials. The degree and type of texture are best described quantitatively by the orientation distribution function (ODF), which gives the probability of a particular crystallite in the sample having a specific orientation with respect to the sample axes. The subject of material texture is well developed by Roe [[ROE 65]], [[ROE 66]] and Bunge [[BUN 82]]. In general, most of these materials with preferred crystallographic orientation display anisotropy of physical properties. The anisotropic elastic response, which is strongly induced by texture, in turn influences the formability of a polycrystalline material [THO 90, THO 94]. Ultrasonic techniques provide information about the interior microstructure due to the penetration of ultrasonic waves. In recent years, major advances...
