METHOD OF OXIDE REMOVAL FROM METALLIC POWDER

摘要

Metal particles in powdered form are cleaned of oxides by a method in which the particles are introduced into a plasma stream in the presence of a continuous negative transfer arc. Ionization of a gas within a plasma gun produces a plasma stream into which the metal particles are introduced at a location within the plasma gun. A negative transfer arc power source is continuously coupled between the plasma gun and a cathode downstream of the plasma gun and within the plasma stream to remove oxide coatings from the metal particles as they travel along the plasma stream to either a receptacle located downstream from the cathode or to a substrate which forms the cathode and onto which a relatively oxide-free coating is formed by the metal particles. Such methods of oxide removal are particularly effective with highly oxidizable refractory materials such as titanium, tantalum and aluminum.