THE EFFECT OF CHROMIC-ACID TREATMENT ON THE MECHANICAL AND TRIBOLOGICAL PROPERTIES OF ARAMID FIBER-REINFORCED ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE COMPOSITE

Surface oxidation of ultra-high molecular weight polyethylene (UHMWPE) powder has an influence on the mixing procedure of chopped fibres and UHMWPE powder. Due to this oxidation hydrogen bonds can be formed bet ween the fibres and powder particles, leading to a more homogeneous fi bre-powder mixture. This treatment improves the fibre-matrix interface and thus the physical properties of the composite. Chromic acid treat ment also has an influence on the mechanical and tribological properti es of the aramid-UHMWPE composite. Although only a relatively small im provement is observed in the modulus, yield stress and stress at break , of 33, 17 and 9%, respectively, a substantial enhancement in wear re sistance of 117% is observed.