(5) Electrolytic etching applications

Electrolytic etching process can create complex shapes with a single pass and is not affected by material's hardness or toughness. The process offers greater benefits for complex applications with materials that are hard to machine by conventional means.

For instance, when the tool radius is small the tool rigidity also becomes small, and the cutting depth must be reduced. This will greatly reduce the process efficiency. Choosing the electrolytic machining in such cases would be quite effective.

Let's examine some applications that relates to the above.

1) Electrolytic drilling

For drilling operations, tubes with various cross sections are used as electrodes.

As shown in [Fig.1], the tube's exterior is insulated with epoxy resin or similar, with a somewhat wide land on the end. The insulation on the tube's sides prevent unintended excess over-cutting of the hole ID by any stray current. This countermeasure is not necessary for certain types of electrolytes. It is said that solution such as NaNO3 with small throwing power can minimize the over-cutting to virtually zero. A product example is shown in [Fig.2].

Curved hole drilling

Electrolytic drilling can be utilized to create curved holes or slots easily. This can be accomplished by using a long electrode shaped in an arch, and feeding it in the circumferential direction as shown in [Fig.3].