Friction and wear properties of carbon fabric composites treated by oxidation in acid mixtures of HNO₃/H₂SO₄

Carbon fabric composites (CFC) were treated by oxidation in different acid mixtures of HNO₃/H₂SO₄. The carbon fabric composites sliding against AISI-1045 steel in a pin-on-disk configuration and under dry friction conditions were investigated on a Xuanwu-IE friction and wear tester. The chemical structure and shear strength of carbon fabric composites were analyzed through fourier transform infrared spectroscopy and universal materials tester respectively; the worn surfaces of the carbon fabric composites were observed by SEM. The load carrying capacity, shear strength, friction-reducing and anti-wear properties of the carbon fabric composites were greatly improved by the oxidation treatment of the acid mixtures of HNO₃/H₂SO₄, and the load carrying capacity of the treated carbon fabric composites increased by 60%, while its wear rate decreased by 65.9%. Furthermore, the carbon fabric composites under higher temperatures exhibited much better friction-reducing and the anti-wear properties than under room temperature, and the treated carbon fabric composites exhibited better friction and wear properties than the untreated carbon fabric composite under higher temperatures. There were some active chemical groups on the surfaces of carbon fabric after the oxidation of acid mixture, the cohesive force between carbon fabric and adhesive was enhanced, so the carbon fabric composites exhibited improved friction-reducing, wear resistance and temperature-resistant ability.