RESUMEN
A new method for the determination of the crystallographic indices of planar fracture surfaces is described. The key innovation is the use of a focused ion beam instrument to extract two transmission electron microscopy (TEM) foils from the fracture surface. Selected area diffraction of these foils in the TEM allows the determination of the fracture plane from the cross product of two crystallographic line directions contained within the plane. This allows the indices to be determined from relatively small fracture surfaces, affording fracture plane determinations from facets on polycrystalline samples. The validation of this method using cleavage fracture in pure zinc is described.
RESUMEN
Electron backscatter diffraction was used to examine the recrystallization behaviour of warm, clock-rolled uranium. A new uranium preparation method was developed, resulting in acceptable specimen surface finishes nearly every time, even for as-rolled specimens. Recrystallized fractions were differentiated from unrecrystallized fractions using differences in the grain average misorientation, a measure of the internal level of misorientation within a grain. This new approach better estimates the recrystallized fraction than hardness measurements, and has the advantage over standard metallographic techniques of providing texture information.