Grain-Specific Texture Measurements

In order to obtain the fullest possible picture of the interrelationship between texture, microstructure and properties it is necessary to collate data on a “microtextural” (i.e. grain specific) basis, in addition to more conventional macrotexture measurements. This paper describes two methods for the acquisition of microtextural data, the electron backscattering diffraction technique in a scanning electron microscope, and convergent beam electron diffraction in a transmission electron microscope. The former method is particularly suitable for the collection of large quantities of data, and examples of its use are included. In addition to an inverse pole figure presentation of texture, orientation measurements which arise from contiguous grains may be analysed from the standpoint of the grain misorientation texture (GMT). From this type of microtextural data the proportion and distribution of grain boundaries which possess special properties can be obtained. Since it has recently been recognised that the properties of special boundaries have a significant influence on the overall properties of the material, the ability to collect and analyse easily such data in statistically significant quantities represents an extremely powerful research technique. Finally, a method for computer generation of GMTs, both from randomly oriented and textured grain aggregates is described and compared with the experimental case.