Erosion resistance enhancement of polymeric composites with air plasma sprayed coatings

This paper addresses the fabrication and performance evaluation of a solid particle erosion resistant layer for polymer-based composites. Air plasma spray (APS) was used to deposit three different coating materials (tungsten carbide-cobalt, martensitic chromium stainless steel, and alumina-titania) as an erosion resistant layer on top of a carbon/epoxy composite. A woven wire, stainless steel mesh was placed on top of the composite substrate during the composite fabrication process with the intention of producing a protection for composite fibers during grit blasting and thermal spraying, enabling the deposition of relatively harder materials on the composite and enhancing the adhesion strength between coatings and substrate. Desirable processing parameters for grit blasting and plasma spraying were also identified. Several tests were conducted on the coated samples to determine their mechanical and tribological performances. Using flatwise tensile tests, it was shown that the identified processing parameters could significantly improve the coating bonding strength. Solid particle resis-tance tests were also performed using air-jet erosion (ASTM G76) as well as hardness measurements on the coated samples. It was observed that coating materials with a brittle behavior offer a higher erosion resistance when they are sprayed on stiff and hard substrates. It was established that these coatings require strong support from the hard substrate to be more durable against erodent particles. Experimental results also indicate that coating materials with a ductile behavior are more desirable to be deposited on less stiff (soft) substrates such as carbon fiber reinforced composites.

Automated summary

This paper investigates the fabrication and performance evaluation of a solid particle erosion resistant layer on polymer-based composites. Coating materials including tungsten carbide-cobalt, martensitic chromium stainless steel, and alumina-titania were deposited using air plasma spray (APS) to enhance erosion resistance. A stainless steel mesh was incorporated during composite fabrication to protect the composite fibers during grit blasting and thermal spraying, improving the adhesion between coatings and substrate. Tests were conducted to assess mechanical and tribological properties. Results showed that coating bonding strength significantly improved with identified processing parameters. Coating materials with brittle behavior exhibited higher erosion resistance on stiff substrates, while ductile coatings were more suitable for less stiff substrates like carbon fiber reinforced composites.