Electrochemical machining (ECM)
<p>1 Pump, 
2 Anode (workpiece), 
3 Cathode (tool) that is movable in all directions, 
4 Electric current, 
5 Electrolyte, 
6 Electrons, and 
</p>
7 Metal hydroxide
<a href="//commons.wikimedia.org/wiki/User:Laurensvanlieshout" title="User:Laurensvanlieshout">Laurensvanlieshout</a>
CC BY-SA 4.0
<span class="int-own-work" lang="en">Own work</span>