Patent ID: 6841754

Claim:
A plasma arc torch comprising: a torch body for holding an electrode, the torch body including a plasma flow path for directing a plasma gas to a plasma chamber; a composite electrode; and a nozzle mounted beneath the composite electrode, the nozzle and the composite electrode defining the plasma chamber, wherein the composite electrode comprises: an electrode body having a forward portion and an aft portion, the aft portion comprising a first metallic material and having a first mating surface; the forward portion comprising a second metallic material and having a second mating surface configured to join with the first mating surface such that an interior surface of the forward portion is directly cooled by a coolant, the first and second mating surfaces being in direct contact with each other; wherein the first and second metallic materials have a heat transfer property, the value of the heat transfer property for the second material being greater than that of the first metallic material.