Electroforming is basically a specialised form of electroplating.
In electroplating, metal is dissolved electrolytically at an anode.
The resulting metal ions are transported through an electrolyte
solution, usually containing a high concentration of the
same metallic ions, to be deposited at a cathode.
The anode and cathode in the electroforming cell are both connected to an external supply
of direct current .
The anode is connected to the positive terminal of the supply, and the cathode (article to be plated)
is connected to the negative terminal.
When the external power supply is switched on, the metal at the anode is oxidized from the zero valence state
to form cations with a positive charge.
These cations associate with the anions in the solution.
The cations are reduced at the cathode to deposit in the metallic, zero valence state.
For example, in an acid solution, copper is oxidized at the anode to Cu2+ by losing two electrons.
The Cu2+ associates with the anion SO42- in the solution to form copper sulfate.
At the cathode, the Cu2+ is reduced to metallic copper by gaining two electrons.
The result is the effective transfer of copper from the anode source to a plate covering the cathode.
The plating and forming is most commonly a single metallic element, not an alloy.
However, some alloys can be electrodeposited, notably brass .
Principle of electroforming...