Abstract:Asynchronous rolling reduces rolling force through the cross-shear effect, significantly influencing the plastic deformation behavior of zirconium alloys, and serves as an effective approach to optimize texture characteristics in Zr-Sn-Nb alloys. In this study, Zr-Sn-Nb alloy sheets were subjected to asynchronous rolling at a speed ratio of 1.13 along the RD-TD (0° sample) and RD-ND (90° sample) directions. By combining electron backscatter diffraction and intra-grain misorientation axis (IGMA) analysis, the effects of initial orientation and deformation amount on microstructure evolution, slip system activation, and deformation mechanisms during asynchronous rolling were investigated. The results demonstrate that with the increase in deformation, both oriented samples exhibit significant grain refinement and a progressive rise in the fraction of low-angle grain boundaries. Throughout rolling, the 0° sample retains a bimodal texture, whereas the 90° sample undergoes a texture transition from <0001>∥TD to a bimodal texture. IGMA analysis reveals that prismatic <a> slip dominates the early deformation stage in both samples. As strain accumulates, competition arises between prismatic <a> slip and basal <a> slip. In the 0° sample, prismatic <a> slip remains the predominant deformation mode, with negligible contributions from other mechanisms. In contrast, plastic deformation in the 90° sample is cooperatively accommodated by {102} twinning, prismatic <a> slip, basal <a> slip, and pyramidal <a> slip.