Accession Number : ADA188633

Title :   The Effects of Thin Polymeric Surface Films in Reducing Fretting Corrosion and Wear.

Descriptive Note : Final rept. 1 Oct 83-31 Aug 87,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG

Personal Author(s) : Furey, M J ; Eiss, N S , Jr ; Mabie, H H

PDF Url : ADA188633

Report Date : 30 Oct 1987

Pagination or Media Count : 20

Abstract : The subject of this investigation was the use of polymeric films to prevent fretting corrosion and wear. The friction and wear of the films was measured in an apparatus in which a ball was reciprocated on a flat. The measure of wear was the time required for the film to be worn through to the substrate. All of the polymers tested were thermoplastics or non-crosslinked elastomers. The following factors were investigated: normal load, frequency and amplitude of motion, film thickness, humidity, and atmosphere composition. There was a wide variety in the lives of polymeric films in a fretting interface. Polyvinyl chloride consistently exhibited the longest film lives. Some of the films caused damage to the steel ball, e.g., polyvinyl chloride, while others, such as polystyrene, did not. Almost all solvent cast films debonded from the substrate during the fretting test. This debonding contributed to the reduction in film life, particularly for elastomers for which debonding was a precursor for crack formation. The failure mechanisms varied with power composition. Polystyrene and PVC failed by plastic flow followed by wear particle formation by a fatigue process. The elastomers failed by debonding, crack initiation and propagation which is exposed the substrate to the ball. Temperature rises in fretting interfaces appear to be quite low and thus would not contribute significantly to film degradation or softening.

Descriptors :   *CORROSION, *FRETTING, *FRICTION, *POLYMERIC FILMS, *WEAR, AMPLITUDE, CASTINGS, CRACKING(FRACTURING), CRACKS, DEGRADATION, ELASTOMERS, FATIGUE, HUMIDITY, INTERFACES, MOTION, PARTICLES, PLASTIC FLOW, POLYSTYRENE, POLYVINYL CHLORIDE, SOLVENTS, SUBSTRATES, SURFACES, THICKNESS, THIN FILMS

Subject Categories : Polymer Chemistry
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE