Abstract
? 2022 Elsevier B.V.The effect of reduction on microstructure evolution and mechanical properties in a near α-Zr alloy (Zr0.5Be, wt%) has been studied in detail during cold rolling. The results indicate that the strength of (002)α texture increases gradually with the increase of reduction, which can be attributed to the activation of base slip of α phase under high stress concentration. In the process of cold rolling reduction from 0% to 70%, deformation mode of the α-laths changes from rigid rotation along the RD direction to plastic strain gradually. Microscopic analysis results show that the dislocation slip dominates the plastic behavior of the alloy and the evolution path of the microstructure can be described as: (I) the stage of increasing dislocation density, (II) the stage of dislocation wall and dislocation cell formation, (III) the stage of subgrain formation, and (IV) the stage of nanocrystalline formation. Also, as the reduction increases from 0% to 70%, the tensile strength increases while the fracture elongation decreases. The sample subjected to 70% reduction can display the highest ultimate tensile strength (~ 930 MPa) and retain a fracture elongation of 8.6%. The combined effects of fine grain strengthening, dislocation strengthening and strain hardening play a leading role in the increase of strength and decrease of fracture elongation.
NSTL
Elsevier