Study of internal strain evolution in Zircaloy-2 using polycrystalline models: Comparison between a rate-dependent and a rate-independent formulation

Study of 3-D stress development in parent and twin pairs of a hexagonal close-packed polycrystal: Part I – in-situ three-dimensional synchrotron X-ray diffraction measurement

“…This slab has been well characterized by the authors with in-situ neutron diffraction experiments [29] and various types of crystal plasticity modeling [2,30]. The slab has an hcp crystal structure at room temperature with nominal composition Zr, 1.2-1.7 wt% Sn, 0.07-0.2 wt% Fe, 0.05-0.15 wt% Cr, 0.03-0.08 wt% Ni, 1400 ppm oxygen [31].…”

Twinning and de-twinning in beryllium during strain path changes

“…When the deformation twins begin contributing significantly to the (00.2) peak intensity in the IP1 direction, beyond À 0.03 plastic strain, the residual intergranular strain associated with this grain set rapidly increases positively. The tensile shift of the residual intergranular strain to zero or slightly positive where the volume fraction of the twins is roughly equal to the initial minority (00.2) oriented grains indicates that the strains in the twins alone must be positive [46]. This is consistent with several in-situ diffraction measurements during twinning in magnesium [35,36,47] and zirconium [46] which observe twins forming with large tensile intergranular strains, but relied on assumptions about the initial d-spacing of the (00.2) planes.…”

“…The tensile shift of the residual intergranular strain to zero or slightly positive where the volume fraction of the twins is roughly equal to the initial minority (00.2) oriented grains indicates that the strains in the twins alone must be positive [46]. This is consistent with several in-situ diffraction measurements during twinning in magnesium [35,36,47] and zirconium [46] which observe twins forming with large tensile intergranular strains, but relied on assumptions about the initial d-spacing of the (00.2) planes. Also like the previous studies on magnesium, after a certain amount of plastic deformation the intergranular strains start becoming more negative, indicating that after the twins form in a relaxed state, they quickly accumulate elastic strain in subsequent straining increments, presumably because they are now in a very hard plastic orientation where only pyramidal slip can be activated [34,35].…”

Experimental Analysis of Slip Systems Activation in Neutron-Irradiated Zirconium Alloys and Comparison with Polycrystalline Model Simulations

“…Improvement of the modeling can still be obtained by using more advanced homogenization techniques, [30,41,42] by introducing the prismatic channeling which is observed only for axial tensile tests, [9] or by using other experimental techniques such as neutron or synchrotron diffraction experiments. [43,44] …”