Plasma Assisted Debinding and Sintering (PADS) – Metal Injection Molding Application

this paper describes the PADS process and equipment, which has been developed to produce PIM components. The use of a hybrid system of plasma discharge and Mo heating elements makes debinding and sintering PIM components in the same heating cycle possible. The use of an abnormal discharge between a cathode and anode under low-pressure provides reactive specimens that break the polymeric chains of the binder of the molded parts. By the combination of these features it was possible to use heating rates of 2,0º C/min during the debinding step. The hydrocarbons, resulted from debinding, are pumped out through vacuum pumps, without traps. The clean environment makes possible to sinter the parts in the same cycle, as well as execute a surface treatment during cooling. The results present short process times as 6 hours to Fe2Ni0,6C low alloy steel and 7 hours to 316-L stainless steel. Characteristics as density, carbon content and mechanical properties are similar to traditional PIM process. The reduction of energy and gas consumption and shorter lead-times are economic advantages of PADS system. The clean environment of PADS is also an ecological advantage.