Friction and Wear of a Three-Dimensional Fabric-Reinforced Plastic at Room Temperature and Liquid Nitrogen Temperature

Abstract

The friction and wear characteristics for copper slid against ZI-005, a newly-developed, three-dimensional-fabric-reinforced plastic, were examined at room temperature (300 K) and at liquid nitrogen temperature(77 K) to determine its suitability for use in cryogenically-cooled electromagnets. For comparison, the friction and wear characteristics for copper slid against G-10, a conventional two-dimensional-fabric-reinforced plastic,were also measured. The friction coefficient for the copper/G-10 pair increased markedly with sliding distance at 300K, achieving a steady-state value of 0. 75; at 77K the friction coefficient is much lower, ~0. 3, and relatively independent of distance. By contrast, the friction coefficient for copper/ZI-005 is equal to ~0. 5, independent of both sliding distance and temperature. The magnitude of the nondimensional wear coefficients for copper/ZI-005 are equal to ~10⁻⁴, independent of temperature, and are approximately 100 times greater than those for copper/G-10(~10⁻⁶). The magnitude of these wear coefficients, together with an examination of the composites’ surface morphologies, suggest that the surface interactions for copper/ZI-005 are predominantly abrasive, whereas the interactions for copper/G-10 are generally adhesive. Because of its tendency towards abrasive friction, ZI-005 should provide a much stabler friction behavior when used as an insulator between highly-stressed copper windings.

Visiting scientist to the Francis Bitter National Magnet Laboratory, September and October, 1989.