Electroforming Process and Application to Micro/Macro Manufacturing

University of Edinburgh, School of Mechanical Engineering, Edinburgh, UK; Department of Mechanical & Aerospace Engineering and Engineering Mechanics, University of Missouri-Rolla, USA; Industrial and Management Systems Engineering, University of Nebraska, Lincoln, USA; Department of Engineering, Glasgow Caledonian University, Glasgow, UK
CIRP Annals - Manufacturing Technology 01/2001; DOI: 10.1016/S0007-8506(07)62990-4

ABSTRACT Electroforming is the highly specialised use of electrodeposition for the manufacture of metal parts. This paper describes the process principles and mechanisms of electroforming, outlining its advantages and limitations. A review of modelling and simulation of electroforming and experimental analysis work is also presented. The metals that can be electroformed successfully are copper, nickel, iron or silver, thickness up to 16 mm, dimensional tolerances up to 1 μm, and surface finishes of 0.05 μm Ra. The ability to manufacture complex parts to close tolerances and cost effectively has meant that electroforming has applications both in traditional/macro manufacturing and new micromanufacturing fields. These include tooling; mould making; fabrication of microelectromechanical systems (MEMS) and the combination of lithography, electroforming and plastic moulding in the LIGA process. Applications in micro-optics and medicine are included.

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    ABSTRACT: A novel technique of electroforming with orbital moving cathode was carried out for the fabrication of non-rotating thin-walled parts. This technique features a large number of insulating and insoluble hard particles as a real-time polishing to the cathode. When cathode moves, hard particles polish its surface and provide the nickel non-rotating parts with near-mirror finishing. Morphology, microstructure, surface roughness and micro hardness of deposits fabricated by novel method were studied in contrast with the sample produced by traditional electroforming methods. Theoretical analysis and experimental results showed that the novel technique could effectively remove the hydrogen bubbles and nodules, disturb the crystal nucleation, and refine the grains of layer. The mechanical properties were significantly improved over traditional method. The microhardness of the layer was in a uniform distribution ranging from 345 HV to 360 HV. It was confirmed that this technique had practical significance to non-rotating thin-walled parts.
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