Tensile strength of electrodeposited nanocrystalline Ni-W alloys with finely dispersed micrometer-sized array through-holes

Electrodeposited nanocrystalline Ni-W alloys with finely dispersed micrometer-sized array through-holes having diameters between 20 mu m and 50 mu m with a regular interval of 100 mu m have been prepared by using UV (ultraviolet light)-lithographic techniques. In the case of monolithic nanocrystalline Ni-16at.% W alloys with a grain diameter of 10-20 nm, the nominal tensile strength and the total elongation at fracture were attained at 1700 MPa and about 1%, respectively. With finely dispersed array through-holes having a diameter of 30 mu m, the tensile strength and the total elongation at fracture increased up to about 2200 MPa and 1.2%, respectively. This may be due to the multiplication of highly localized yielding beginning at the finely dispersed array through-holes that can moderate the propagation of individual shear bands and cracks effectively. (c) 2006 Elsevier B.V. All rights reserved.