The effect of chromic acid treatment on the mechanical and tribological properties of aramid fibre 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 between the fibres and powder particles, leading to a more homogeneous fibre-powder mixture. This treatment improves the fibre-matrix interface and thus the physical properties of the composite. Chromic acid treatment also has an influence on the mechanical and tribological properties of the aramid-UHMWPE composite. Although only a relatively small improvement is observed in the modulus, yield stress and stress at break, of 33, 17 and 9%, respectively, a substantial enhancement in wear resistance of 117% is observed.