抄録
Directed Plasma Fabrication (DPF) is a rapid tooling process that is based on controlled deposition of molten powder particles according to computer-controlled patterns. It makes fully dense, near net shape metal components without molds or dies, and without forming, pressing or forging systems. Experimental works were carried out using conventional low current Plasma Transferred Arc Welding system, and metallic powder was stellite #21. Cylindrical shapes are successfully deposited as dimensions with 2.5-4.2 mm wall thickness. The key factor is the melting efficiency M, which is defined as the ratio of given heat input into base metal and required heat input to melting of deposited metal. Other one is the non-dimensional "operating parameter n" which is proposed by Christensen. As the conclusion, better" deposition efficiency is obtained in case of lower melting efficiency M, this means shorter arc length and slower traveling speed-when the same plasma current conditions are applied.
