Tribocorrosion behavior of Ti3SiC2 in the dilute and concentrated sulfuric acid solutions

In light of the salient physical and mechanical performance combined with good corrosive resistance, Ti3SiC2 is expected to be used as materials for mechanical component in corrosive environment. It is in necessity to investigate the tribocorrsion behavior of Ti3SiC2 in corrosive environment. In the electrochemical test, Ti3SiC2 experienced passivation when potential was positive than the corrosion potential in sulfuric acid (H2SO4) solutions. In the tribocorrosion tests of Ti3SiC2 against Si3N4 in dilute (1 M) and concentrated (10 M and 15 M) H2SO4 solutions, mechanical removal of material owing to decoherence of Ti3SiC2 grains led to high wear for Ti3SiC2. In the concentrated H2SO4 solutions, an amorphous SiO2 layer formed by chemically corrosive oxidation acted as lubricant reducing friction coefficient and wear by eliminating decoherence of grains. However, mechanical decoherence of Ti3SiC2 grains prevailed again when the load increased. Tribocorrosion behavior of Ti3SiC2 strongly depended on the alternative domination of mechanical or chemical effects.