The tensile properties and fracture behavior of gradient nano-grained/coarse-grained zirconium

The tensile properties and fracture behavior of gradient nano-grained/coarse-grained zirconium produced by surface circulation rolling treatment were investigated. Experimental results indicated that gradient nano-grained zirconium foil exhibits high yield strength (∼748 MPa) and reduced tensile elongation (∼3.0%) relative to its coarse-grained counterpart. On the contrary, the gradient nano-grained/coarse-grained zirconium shows good mechanical properties which combine the strengthening from nanocrystalline zirconium with the strain hardening provided by coarse-grained zirconium. Localized plastic deformation is effectively suppressed, instead of a uniform and fish-scale overall deformation.