Nanomechanical properties of nanocrystalline Ni-Fe mold insert

Abstract

Nanocrystalline Ni-Fe alloy micro-mold inserts were fabricated by UV lithographic technology and pulse current electroforming process. The structure, surface and mechanical properties of Ni-Fe alloys were evaluated under different pulse current electroforming processes via X-ray diffraction (XRD), scanning probe microscope (SPM), nanoindentation, and scanning transmission electron microscope (STEM). The results show that when Fe content of the alloys increase by over 10% the grain size of Ni-Fe alloys was < 20 nm. The finer the grain of Ni-Fe alloys the higher the hardness, which is above 9 GPa. By controlling the variation of current density and duty cycle, the surface roughness of Ni-Fe alloys is < 10 nm and the surface friction coefficient is about 0.2. The results of the microelectroforming process revealed that the Fe contents was able to suppress grain growth and induced the formation of dense Ni-Fe alloys and improved the mechanical properties of the Ni-Fe alloys. (C) 2003 Elsevier B.V. All rights reserved.