Thats not that easy. As soon the two metals are seperated, there will be an arc. The arc is really, really hot and will burn everything and also as soont there is an arc, the arc stays can bee so much much longer in discance than just air. Since there is 0 in DC, large DC-switches are much more difficult to build. There are several options from SF6 (today no), to vacum or blowing magnets (blow the arc to cooling cambers).
