Deformation behaviors of gradient nanostructured superelastic NiTi shape memory alloy

Deformation behaviors of the gradient nanostructured superelastic NiTi shape memory alloy strip with grain size ranging from 20 to 175 nm along the tensile axis are investigated. Compared with the commercial NiTi of uniform grain size, the gradient nanostructure leads to the increase of transformation stress as well as the morphology change, from localized deformation to homogeneous one. However, the behaviors in local different grain size regions are independent and maintain the grain-size dependent characteristics.