Production of high-precision micro metallic components by electroforming process

ABSTRACT

In this study, nickel (Ni) micro components with high precision were produced by electroforming using a soft mold produced by soft lithography and photolithography techniques. The effects of current densities on the microstructures and mechanical properties of the fabricated micro components were studied. It is found that a high-precision soft mold was successfully fabricated and micro Ni gears with sharp walls and fine features were produced. A feature size as small as approximately 70 µm, a height of 380 µm, and a pitch diameter of 3 mm were achieved for the gear. The densities of the gears electroformed are found to be within the range of 5.24–2.95 g/cm³ when current densities utilized vary between 50 and 10 mA/cm². A lower current density leads to a finer microstructure and a larger value of microhardness. Meanwhile, by changing the current density from 50 to 10 mA/cm², the grain size decreases from around 50 to 30 nm while the microhardness increases from 220 to 410. In addition, the preferred orientation of the Ni matrix changes from (111) to (200) or (220) with the decreasing current density.

KEYWORDS:

• Current
• density
• electroforming
• gear
• lithography
• microstructure
• mold
• photoresist
• precision
• property