Investigation of Texture and Interfaces in a Zr–2.5Nb Alloy with Zirconium Hydrides

Crystallographic Texture and Volume Fraction of α and β Phases in Zr-2.5Nb Pressure Tube Material During Heating and Cooling

“…[24,25] C. Pole Figures from an As-Received Zr-2.5Nb Pressure Tube Sample on Heating and Cooling Figure 9, the a-phase texture is found to be quite stable, with little change in the {0002} and 11 " 20 È É pole figures during heating to 1123 K (850°C). It can be seen that the a-phase {0002} and 11 " 20 È É pole figures at 373 K (100°C) and up to 973 K (700°C) are much the same as those measured at room temperature in a earlier study [3] (Figure 2). By comparison, the a-and b-phase textures obtained between 373 and 873 K (100 and 600°C) in this study are similar to but show a much sharper texture than those previously measured on a cold-worked Zr-2.5Nb tube that was initially heated at 898 K (625°C) before being heated to 1248 K (975°C) and cooled back down to 898 K (625°C).…”

“…2-a-phase (0002) and 11 " 20 À Á pole figures for as-received Zr-2.5Nb pressure tube at room temperature obtained from neutron diffraction measurements using a texture goniometer with a constant wavelength and well-resolved individual diffraction peaks [3] . [2] The vertical dashed line in the phase diagram corresponds to the Zr-2.5Nb composition where neutron measurements were performed at eight different temperatures traversing across different phase fields, as shown by the points indicated along the temperature (dashed) line.…”

“…[2] The deformed hcp a-Zr grains exhibit a strong crystallographic texture with a large concentration of the basal (0002) plane normals aligned in the hoop direction of the tube and the prism 11 " 20 À Á poles oriented in the tube's radial direction ( Figure 2). [3] The crystallographic textures are developed primarily during the high-temperature extrusion of the billet to form the pressure tube. As a result of the strong crystallographic texture of the a phase developed during manufacturing, the pressure tube material exhibits anisotropic mechanical behavior.…”

Grain boundary misorientation distributions in monoclinic zirconia

“…The highly protective zirconium oxide layer which can also act as a barrier to hydrogen permeation has been studied in recent years by several authors (e.g. [2][3][4][5]). It has been established that monoclinic zirconia, which is formed during processing and service on the surface of the tubes made of Zr alloys, consists mainly of columnar grains with a transverse diameter of approximately a few tens of nanometres and an aspect ratio of about 10.…”