Microscopic stress and crystallographic orientation of hydrides precipitated in Zr-1Nb-0.01Cu cladding tube investigated by high-energy X-ray diffraction and EBSD

[摘要] The newly developed Zr-1Nb-0.01Cu fuel cladding tubes were hydrogen-charged using the electrolytic technique and cooled down to room temperature after thermal treatment by furnace cooling (FC) and air cooling (AC). High energy X-ray diffraction and electron backscatter diffraction techniques were employed to measure the microscopic stress and crystallographic orientation of hydrides precipitated in FC and AC tube samples. The FC delta-hydrides precipitated in the Zr-1Nb-0.01Cu cladding tube were under an average compressive stress of about (-262.2 +/- 20) MPa. While an average compressive stress of about (-152.4 +/- 20) MPa was determined for the AC delta-hydrides precipitated in the Zr-1Nb-0.01Cu cladding tube. Nearly all the inter- and intra-granular d-hydrides obtained during FC and AC followed the conventional (0001)(alpha-Zr) parallel to (111)(delta-hydride) orientation relationship (OR) with the alpha-Zr matrix. The unusual (0001)(alpha-Zr) parallel to (100)(delta-hydride) OR was only occasionally detected in the FC and AC intra-granular delta-hydrides. Interestingly, for the FC sample, delta-hydrides were simultaneously detected in an alpha-Zr grain, obeying (0001)(alpha-Zr) parallel to (111)(delta-hydride) OR and (0001)(alpha-Zr) parallel to (100)(delta-hydride) OR with the same parent alpha-Zr grain respectively. (C) 2020 Elsevier B.V. All rights reserved.

[发布日期] 2020-12-15

[关键词] Hydride;Zirconium alloy;High energy X-ray diffraction;Orientation relationship