The recovery of deformed beryllium was studied with mechanical testing and in situ neutron diffraction measurements. The initial texture of the material and the deformation rate were manipulated to produce four distinct deformation micro structures. The dislocation density was determined from line profile analysis of the neutron diffraction data collected as a function of temperature during annealing to a maximum homologous temperature of 0.53 following deformation. Mechanical testing was completed after the in situ annealing to determine the extent of the recovery of the flow stress. Both the dislocation density and flow stress recovered significantly by a relatively low homologous temperature of 0.3. A comparison with model calculations using a dislocation-based hardening law indicates that it is forest-type dislocations that annihilate during the relatively low temperature anneal; the dislocation substructure was stable at these temperatures. Finally, the motion of the dislocations during annealing prevented the development of intergranular thermal stresses due to the crystallographically anisotropic thermal expansion of beryllium.
|Number of pages||11|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - Aug 30 2013|
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys