Accession Number : ADA307855

Title :   Wear Rate and Friction Coefficient in Liquid Nitrogen and Hydrogen of Steel Sliding on Polymer Laminates (Various Fabrics and Polymers.

Descriptive Note : Technical note,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Wisander, Donald W. ; Johnson, Robert L.

PDF Url : ADA307855

Report Date : APR 1968

Pagination or Media Count : 15

Abstract : Wear rates and coefficients of friction of polymer laminates were determined in environments of liquid nitrogen and liquid hydrogen. The polymers included PTFE (polytetrafluoroethylene), phenolic, epoxy, and melamine; the fabrics included glass, graphite, nylon, and cotton. The reference material used was not a laminate (80 percent PTFE, 15 percent glass fiber, and 5 percent graphite). Wear and friction experiments were conducted with a 3/16-inch- (4. 8-mm-) radius hemispherical rider sliding on a flat disk, which was rotated to produce sliding velocities of 2300 feet per minute (701 m/min). The 304 stainless-steel riders were under a 1- kilogram load against the polymer laminate disks. The results of this investigation indicated that the graphite-fabric phenolic laminate is a potentially useful material for sliding contact in liquid nitrogen and that glass-fabric PTFE and graphite-fabric PTFE laminates are potentially useful in both liquid nitrogen and liquid hydrogen. The wear rates and coefficients of friction of 304 stainless-steel riders against the laminates were appreciably lower in liquid nitrogen than in liquid hydrogen. p2

Descriptors :   *POLYMERS, *LAMINATES, *STEEL, *COEFFICIENTS, *WEAR, *LIQUID HYDROGEN, *LIQUID NITROGEN, *FRICTION, *SLIDING CONTACTS, VELOCITY, ENVIRONMENTS, NYLON, GRAPHITE, HYDROGEN, GLASS FIBERS, DISKS, EPOXY COMPOUNDS, HEMISPHERES, RADIUS(MEASURE), PHENOLIC PLASTICS, COTTON, MELAMINES.

Subject Categories : Polymer Chemistry
      Inorganic Chemistry
      Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE