Air Force Materials Laboratory, Wright-Patterson AFB, Ohio
Pages: 21 Published: Jan 1974
The influence of materials construction variables on the erosion behavior of fiber-reinforced polymeric composite materials in subsonic rain environments is described. The void content and type of reinforcement are shown to significantly influence the behavior of fiber-reinforced composite structures in a subsonic rain erosion environment whether uncoated or coated. The effects of various fiber layup schemes with a particular fiber reinforcement have been found to be minor compared to void content effects. The addition of reinforcement to thermoplastic resin matrices increases the erosion rates of these materials by breakage of fibers and resulting loss of material. In thermosetting resins, the addition of reinforcement reduces the erosion rate of a bulk material by limiting the chunking and breakout of large pieces. Polymeric coatings such as epoxies, polyesters, and armde-imides are brittle relative to the impringing water droplets with rupture of the film occurring very rapidly. The most resistant coatings; that is, elastomeric polyurethanes, typically show no surface erosion at all but fail at isolated points associated with a breakdown of the composite (that is, glass-epoxy) underneath the coating. Other elastomeric coatings such as neoprene or fluorocarbon will gradually erode on the surface by structural failure or tearing within the film; erosion of the composite then follows.
composite materials, water erosion, subsonic, reinforced plastics, polymers, materials parameters, voids, thermoplastic resins
Paper ID: STP35496S