Controlled fabrication and electrochemical corrosion behavior of ultrathin Ni-Cu alloy foil

Abstract

Cost-effective ultrathin alloy foils (<20 μm) are highly expected with the development of electronic industry and micro-system technology. In this paper, electrodeposition combined with vacuum sintering is used to fabricate a Ni-Cu alloy foil with thickness of 12.0 (±0.2) μm. For the ultrathin Ni-Cu alloy foil, a densified structure without pores can be achieved by prolonging sintering duration at 900 ℃ for 3 h. Under the current density of 10 mA cm−2, 700 s is the optimal electrodeposition time to obtain the highest tensile strength (187 MPa) with the Ni content of 41.5 wt.% in the alloy foil. Compared with Cu foil, Ni-Cu alloy foil shows superior corrosion resistance in 3.5 wt.% NaCl solution and also HCl solutions (0.5 mol/L, 1.0 mol/L, 2.0 mol/L), respectively. The uniform composition and defect-free surface, excellent tensile strength and corrosion resistance together exhibits the great application potential of the obtained Ni-Cu alloy foil, which may provide an inspiration for future development of integrated electronic or medical devices.