EDM vs ECM

I was reading an old reference today about ECM, now called AM or Anode
Machining. The reference sparked my interest because of something
someone said last week about dielectric fluid for EDM and asking if an
electrolyte should be added. Or course the EDM fluid has to have good
dielectric properties and can't have any conductivity, if possible.

Even so, the idea of salt water came up and in ECM or AM, salt water is
exactly what is used. The power supply is simple but extremely
powerful. A good one would have variable voltage from 6 to 30 Vdc and
be able to deliver massive amounts of current - up to 20,000 ampers -
but that would be impractical for a home shop. I haven't found the
minimum current practical for AM as yet.

These machines also use an electrolyte filtration system to remove the
metal salts formed during machining. They also use fairly high pressure
to push/flush the space between the electrode and the workpiece.
Otherwise, they are fairly simple and work much faster than an EDM machine.

The reference I have says that it is common to bore 0.050" holes into
turbine blades that are 12" or more long using ECM at a speed that makes
it practical Not bad.

So as a corollary to EDM, maybe someone here would be interested in ECM/AM??

JerryK