Cast iron substrates reclamation by tape casting of NiCu treated by plasmatransferred arc: optimization of the tape and its plasma treatment

Plasma transferred are (PTA) is now currently used for reclamation of worn materials or to provide wear or corrosion resistant coatings welded to the base material. Instead of injecting the powder in the plasma and the molten pool created at the coated surface, a tape casting process was used to obt ain an adherent powder layer of NiCu (70:30) on the material surface. Tapes deposited on cast iron substrates exhibited a high electrical resistance ( a few G Ohm). Thus, their PTA treatment has been carried out by starting th e electrical are on the metallic cast iron substrates. The: process control by charge coupled device (CCD) camera showed that the NiCu particles fell in the melting pool created at the substrate surface. The study of the obta ined alloy compositions has shown the drastic influence of the initial bind er concentration in the tape. Some NiCu tapes were sintered on their substr ate at 1100 degreesC for 4 h under an inert atmosphere. The resulting coati ngs, characterized by a low electrical resistance (a few Ohm), and a good a dhesion to the substrate, were then treated by PTA. The surfacing alloy pro perties were compared to those obtained without heat treatment. (C) 2001 El sevier Science B.V. All rights reserved.