Study on the deposition of stainless steel on polymeric substrates by arc electric thermal spraying

It is known that application areas of plastics can be enlarged by imparting special features such as higher electrical and thermal conductivity by surface metallization of these materials. Still, there are very limited studies on the metal deposition on polymeric substrates by thermal spray process due to various limitations and problems associated with this aspect, although some reports are available on the fabrication and characterization of bonding layers using low melt temperature materials. With this background, this study was taken up with the objectives of deposition of 309L stainless steel on some polymeric substrates (PP, Nylon 66 and PVC) by electric arc thermal spray process through a prior development of a bond coating. This bond coating was based on epoxy resin/micro silica with scattered and packed metal particles anchored over it, which changed the nature of the substrate surface creating a favorable topology for adhesion and scattering of the sprayed particles. Coatings having an average thickness of 129.06 μm of stainless steel and 259.06 μm of bonding layer (epoxy/micro silica) were obtained over a polyvinyl chloride (PVC) substrate, which had the smaller difference of coefficient of thermal expansion with the bond coat. Obtained coating showed good electrical conductivity value. This kind of favorable metallization of plastics could expand its application areas and might be potential candidate to replace expensive metallic or ceramic materials in special applications.