Nb/NiTi laminate composite with high pseudoelastic energy dissipation capacity

NiTi shape memory alloys (SMAs) with marked hysteresis between the forward and reverse martensitic transformations are attractive for the applications in passive damping. However, the stress hysteresis of NiTi SMAs is usually 150–300 MPa, limiting their energy dissipation to ∼10 MJ/m3. Here, we designed a bulk Nb/NiTi laminate composite with a reversible energy dissipation capacity of ∼30 MJ/m3 and a plateau strength of ∼750 MPa, which are outstanding among the common bulk energy dissipation materials. This high performance is attributed to the strong interaction between the pseudoelastic NiTi and the non-pseudoelastic Nb lamellae within the composite. The intrinsically plastic Nb layers deform in a pseudo-super elastic manner, involving elastic lattice deformation, reversible motion of dislocations, and reversed plastic deformation. These are enabled by the unique phenomenon of lattice strain matching the martensitic transforming. This study offers a new pathway for the design of high energy dissipated bulk materials.