Texture development in S200-D, -E and P31664 beryllium blocks from neutron diffraction spectra

Abstract

S200-D, -E, and P31664 beryllium blocks from the LANL archive develop simple fiber texture with {l_angle}0001{r_angle} fiber axis offset from the hot-pressing direction when manufactured by powder processing methods and VHP consolidation. For both S200-D and S200-E vintages sharp fiber texture follows Braun-type attrition. The S200-F vintage possesses a broader starting fiber texture, due to powder processing by impact grinding. Evidence from difference pole figures suggests powder procedures of the sort in this study impose a starting fiber texture before consolidation and that texture strength and symmetry in beryllium is dependent on details of powder processing in addition to the consolidation method. This study documents the close relationship between the fabrication process and resulting texture in polycrystalline beryllium. Physically-based performance prediction of beryllium components must include quantitative measurements of crystallographic texture, in addition to grain size, oxide content, temperature and strain rate measurements, if the prediction is to be accurate. There are numerous other vintages in the beryllium stockpile manufactured by other means such as ball milling that must be characterized. Mechanical properties, aging effects, fracture anomalies, stress corrosion cracking and effective viscosity of beryllium are directly linked to crystallographic orientation. Texture will be integrated into the control monitoring ofmore » the mechanical database for beryllium at LANL.« less