Plasma arc torch

A plasma arc torch, comprising:

• an electrode comprising an electrode holder and an electrode element, said electrode holder having a tip portion, said tip portion having an outer side surface and an end surface, said electrode element having a high melting point and being embedded in said end surface of said tip portion of said electrode holder;
• a nozzle which is electrically insulated from the electrode, said nozzle being positioned coaxially with and exteriorly of said electrode, said nozzle being provided with a nozzle orifice so that said electrode element faces said nozzle orifice, and
• a working gas passage between said outer side surface of said tip portion of said electrode holder and said nozzle for supplying a working gas, wherein, upon application of a high frequency voltage, insulation breakdown occurs in a section of said working gas passage between said outer side surface of said tip portion of said electrode holder and said nozzle so that a pilot arc can be generated and the thus generated pilot arc moves, with flow of working gas through said working gas passage, downstream along said outer side surface of said tip portion of said electrode holder to said electrode element,
• wherein said outer side surface of said tip portion of said electrode holder has an electrode surface which faces said nozzle across said section of said working gas passage,
• wherein said nozzle has a nozzle surface which faces said electrode surface across said section of said working gas passage, and
• wherein at least one of said electrode surface and said nozzle surface comprises at least one metal selected from the group consisting of gold and silver.