Corrosion Behavior of Stir Cast Al6061-B₄C/TiB₂ Composites Processed by Post-Accumulative Roll Bonding

In this study, the corrosion behavior of stir cast Al/B₄C and TiB₂ composites was investigated. Reinforcements were added to Al6061 in amounts of 3, 6, and 9 wt.% during stir casting, after which they were undergone five cycles of accumulative roll bonding (ARB) process. The results of electrochemical tests indicated that in the case of as-cast samples, composites with 9 wt.% TiB₂ and 6 wt.% B₄C displayed the highest corrosion resistance, among which the TiB₂ containing sample had the best corrosion behavior. This difference was attributed to the different nature of the reinforcing particles and their distribution. Moreover, it was considered that the ARB process had a positive impact on the corrosion resistance of the samples by causing a uniform distribution of the reinforcing particles in the samples without changing the pitting corrosion mechanism. It was observed that after ARB process, the composite with 6 wt.% B₄C had the best corrosion resistance, compared to the sample with 9 wt.% TiB₂, because it had less structural defects and homogeneously distributed particles.