Effect of amorphous layer thickness on the tensile behavior of bulk-sized amorphous Ni-P/crystalline Ni laminates

Bulk-sized laminates with controllable thicknesses for amorphous Ni-P and crystalline Ni layers were prepared by electrodeposition. A strong dependence of mechanical properties on the thickness of Ni-P layer was revealed. The laminates with thin Ni-P layers display a desirable combination of strength and ductility, which is even better than that of crystalline Ni. In this case, shear banding in Ni-P layers is suppressed with an effective constraint of Ni layers, resulting in ductile fracture of the laminates. With increase in Ni-P layer thickness, the dominant fracture mode of the laminate transits from co-deformation of all layers to shear banding in the amorphous Ni-P layers, resulting in the reduced ductility and brittle fracture.