What is the context?

Electrochemical Machining (ECM) is an important method for removing metal by anodic dissolution in a conducting electrolyte. Metal is removed by a suitably shaped electrode (cathode tool).
ECM is a relatively fast method, with important advantages over more traditional machining methods (mechanical, laser, electrochemical discharge) since it can be applied to any electrically conductive material regardless of its hardness. Moreover, ECM is able to produce smooth, stress and crack free surfaces.
From a methodology point of view, a difference can be made between:

• ECM imaging processes, where the cathode tool shape moves with a certain feed rate (0.1 to 10 mm/min) towards the part and the cathode tool shape is reproduced in the part almost perfectly (e.g. shave heads, airfoils);
• ECM processes producing internal structures in a part (holes, cavities, tubes). This process is also referred to as ElectroChemical Drilling (ECD).

What are the issues?

For ECM imaging processes, the major issue is controlling the narrow electrolyte gap between cathode tool and part, since dissolved metal ions, gas and heat have to be removed from this gap.
For internal ECM processes, a high forced electrolyte flow is still required for removal of metal ions, gas and heat, but in addition the shape of the produced structures depends strongly on the process conditions (electrolyte flow rate, DC/pulsed current or potential difference) and cell configuration (cathode tool shape, position and movement).

What value do we bring?

Elsyca has a unique simulation technology, extensive know-how and experience for the design and optimization of the cathode tool shape and process conditions (pulse parameters, feed rate) in order to obtain a part end shape that is within specifications.
Elsyca will account for following physico-chemical phenomena:

• ohmic drop in the electrolyte;
• cathodic and anodic polarization behavior;
• anodic metal dissolution efficiency;
• gas evolution and removal by the electrolyte flow;
• dissolved metal removal by the electrolyte flow;
• workpiece heating and heat removal.

Electrical phenomena accounted for:

• potential or current process steering;
• DC or (bipolar) pulsed signals;
• contact and wire resistors.

Configuration features accounted for:

• complex 3D workpiece and cathode shapes;
• moving cathode tools;
• topology changes (formation of perforations).