Innovative surface microcracking treatment of polymeric substrate to be coated with plasma sprayed stainless steel

Abstract

Coating of organic substrates to improve properties has attracted interest because of the potential industrial applications for these materials. Thermal spraying is an attractive coating technology for this purpose owing to its high deposition rate relative to competing processes; however, actual industrial applications remain limited because of poor bonding between the polymeric substrate and the thermal sprayed deposit. Consequently, specific surface preparation of the polymer is required in most cases. In the present study, an innovative surface treatment of a polymeric material allowing subsequent buildup of a plasma sprayed coating is reported. This patented process, known as Pinpro, was successfully applied to coat an organic stereolithography substrate with an AISI 316 stainless steel thick (1 mm) deposit. The process consists in creating a population of surface microcracks in the polymer to provide mechanical anchoring for the steel deposit. Methods of surface preparation were investigated and optimised. The main surface modification mechanisms were elucidated and a phenomenological model of coating buildup on the treated substrate is proposed.