The effect of the addition of aramid fibers on tribological properties of the polyimide after ultraviolet or atomic oxygen irradiation

Abstract

The aramid fibers reinforced polyimide composites were fabricated by means of a hot-press molding technique. The mechanical and tribological behaviors of the reinforced composites were studied. The friction and wear properties of the composites, rotating against a GCr15 steel ball, were investigated on a ball-on-disc test rig. To contrast the effects of the ultraviolet radiation and atomic oxygen, experiments without radiation or after ultraviolet or atomic oxygen radiation were conducted. Experimental results revealed that 20% aramid fiber reinforced polyimide exhibited higher modulus. However, the coefficient of friction decreased with the increase of the aramid fiber content. The composites had a lower wear rate value after atomic oxygen radiation. Microstructure of worn surface of the tested composites was inspected by scanning electron microscopy, and X-ray photoelectron spectroscopy study of the composite surface showed that the chemical composition of the surface changed after ultraviolet or atomic oxygen radiation because of the oxidation.