Rapid Tooling Method Using Plasma Transferred Arc

Directed Plasma Fabrication (DPF) is a rapid tooling process that is based on the controlled deposition of molten metal particles according to computer-controlled patterns. It makes fully dense, near net shape metallic components without casting, pressing or forging processes in molds or dies. Experimental works were carried out using a conventional low current Plasma Transferred Arc welding system, and the atomized Stellite #21 powder. Cylindrical shapes are successfully deposited into the wall 2.5-4.2 mm thick. The key factor is the non-dimensional "operating parameter n" which was proposed by Christensen. The better deposition efficiency is obtained with the shorter arc length and the slower traveling speed under the same plasma current.