Posted: 18 April 2006 at 10:40pm | IP Logged

Electroforming is a highly specialized process for fabricating a metal part by electrodeposition in a plating bath over a base form or mandrel which is subsequently removed.

The advantage of the electroforming process is that it faithfully reproduces the form or mandrel exactly, to within one micron, without the shrinkage and distortion associated with other metal forming techniques such as casting, stamping or drawing. And, since the mandrel is machined as an outside surface, close dimensional tolerances and high surface finishes can be held and maintained on complex interior configurations.

Electroformed metal is extremely pure, with superior properties over wrought metal due to its refined crystal structure. Multiple layers of electroformed metal can be molecularly bonded together, or to different substrate materials to produce complex structures with "grown-on" flanges and bosses.

Electroforming should be thought of as a basic manufacturing process when considering alternatives best suited for making any particular item. Other basic metal forming processes including casting, forging, stamping, deep drawing, machining and fabricating may serve well for most applications, but can be pressed beyond their limits when requirements call for extreme tolerances, complexity or light weight. Electroforming is a real problem solver in these instances.

The diagram shows the electroforming process at work. The positively charged electroformed metal source (anode) at the left is broken down (ionized) in the copper electrolyte solution and is attracted to the negative charged mandrel (cathode). Build-up is achieved over all mandrel surfaces at an approximate deposition rate of .001" per hour. The vast majority of electroforming is done with nickel. Copper is the next most widely used metal. Copper’s use is principally in the printed circuit board industry.