I read the article and I'm still kind of confused as to why you say that current determines the distance an arc can travel... Cause it doesn't make much sense, even in the article you linked me, in the first half of the first page it says
"Arc Voltage is that amount of voltage that exists on contacts separated by a small gap that will cause an electric discharge across the gap // And, lastly, Arc Current is that amount of current necessary to just sustain an arc caused by the arc-voltage electric discharge."
Also what we are referring to as an "arc" is most likely an electric spark because the air between the contacts just ionizes and becomes conductive but doesn't turn into plasma. But for our little convo this doesn't really matter as the physics remain mostly the same.
Anyways, here's a few quotes from the "Electric arc" , "Spark gap", "Electric spark", "Breakdown voltage" and "Paschen's Law" Articles on wikipedia, (My books are in greek, otherwise i would have taken pictures).
"The
breakdown voltage of an
insulator is the minimum voltage that causes a portion of an insulator to become electrically
conductive." - Breakdown Voltage
"When the potential difference between the conductors exceeds the
breakdown voltage of the gas within the gap, a
spark forms,
ionizing the gas and drastically reducing its
electrical resistance." - Spark gap // (potential difference = voltage)
"The rapid transition from a non-conducting to a conductive state produces a brief emission of light and a sharp crack or snapping sound. A spark is created when the applied electric field exceeds the
dielectric breakdown strength of the intervening medium. For air, the breakdown strength is about 30 kV/cm at sea level." - Electric spark // Here you can see that the spark/arc ignition isn't that dependent on the "metal type", but instead the intervening medium between them, and if the voltage is sufficient to ionize said medium, (30kV/cm for air), a spark will fly across the contacts.
Now here is where the confusion stemmed from. An electric ARC has a lot do with current, ex. :
"An
electric arc, or
arc discharge, is an
electrical breakdown of a
gas that produces a prolonged
electrical discharge. The
current through a normally
nonconductive medium such as
air produces a
plasma; the plasma may produce
visible light."
- Electric arc
Here there is talk about current, but don't mix them up, sufficient current is needed to turn the air into plasma and maintain that state. That's it... The distance, and for that matter, everything else is determent on the voltage as you can also see here:
"
Paschen's law is an equation that gives the
breakdown voltage, that is, the
voltage necessary to start a discharge or
electric arc, between two electrodes in a gas as a function of pressure and gap length." - Paschen's law
Here you can also see that you need to have the necessary voltage to start an electric arc.
Fun Fact: Lightning is an electric spark