Room temperature tribocorrosion behaviour of Al-4.5%Cu/SiC particulate composite was evaluated against stainless steel ball in natural sea water. Ab-initio, the Al-4.5%Cu was reinforced with 5,10,15 and 20 % SiC reinforcements to produce the Al-4.5%Cu/SiC particulate composite by stir casting method. The tribocorrosion test was carried out with an Anton Paar Tribometer at applied loads of 5 and 7 N. The surfaces of the control and worn out surfaces were characterized by scanning electron microscopy (SEM); the navigation camera of the SEM machine was used to capture the exposed areas of the composite that were subjected to tribocorrosion prior to the SEM. From the results, it was found that the control sample (Al-4.5%Cu) was more susceptible to corrosion and wear in sea water than the reinforced (Al-4.5Cu%/SiC) sample under the loadings considered in this work. The susceptibility to corrosion and wear decreased as the percent composition of the reinforcement was increased; the synergistic action of corrosion and wear (tribocorrosion) decreased as the reinforcement was increased. The pre and post-tribocorrosion scanning electron microscopy (SEM) images of the test samples obtained at magnifications of 2000x and 2500x revealed white patches of SiC particulates embedded in dark areas of Al-Cu matrix regions and appears to be fairly distributed throughout the matrix. It was concluded that the tribocorrosion rate of the test samples decreased with increase in percentage volume fraction of the SiC particulate reinforcement.
Key words: Al-4.5%Cu/SiC; seawater; tribocorrosion; room temperature; synergism; SEM.
