Abstract
The electrochemical corrosion behaviors of Ti(3)SiC(2)/Cu composites in harsh media including dilute HNO(3) and concentrated H(2)SO(4) were studied in detail and the related corrosion mechanisms were explored. Under open-circuit potential, the corrosion resistance of Ti(3)SiC(2)/Cu in dilute HNO(3) was worse than that in concentrated H(2)SO(4). In dilute HNO(3), Ti(3)SiC(2)/Cu exhibited a typical passivation character with a narrow passivation interval. During the corrosion process, the dissolution of Cu-Si compounds resulted in the destruction of the passivation layer on the surface. Additionally, with the increasing of the potentials, the oxidation of Cu and Si atoms led to the generation of the oxide film again on the surface. In concentrated H(2)SO(4), the Ti(3)SiC(2)/Cu composite was covered by a double-layered passivation layer, which was composed of an internal layer of TiO(2) and an external layer of Cu(2)O and SiO(2). This was because Cu diffused into the surface and was oxidized into Cu(2)O, which formed a denser oxidized film with SiO(2). In addition, it was found that Ti(3)SiC(2)/Cu has better corrosion resistance in concentrated H(2)SO(4).