The ceramic nanoparticles (e.g. TiC, TiB2) can increase the mechanical properties of Al alloys. However, their effects on the corrosion performance of Al alloys are relatively less understood. We found that the corrosion resistance of Al-Mg-Si alloys was improved by adding TiC and worsened by adding TiB2. These changes result from i. TiC refining the grain structure by acting as nucleants and reducing the number of grain boundary phases and ii. TiB2 segregating at grain boundaries and accelerating the corrosion. This provides a selection criterion that can be utilized for reinforcement nanoparticles for wrought Al alloys that are applied in corrosive environments.
The increase in strength usually accompanies with ductility loss in structural materials. We proposed a novel approach to the design and fabrication of hierarchically structured Al-Mg- Si alloys/nanocomposites with improved strength and ductility. The layered distribution of TiC nanoparticles, bimodal-sized grains and precipitates were produced in a laminated composite composed of Al-Mg-Si matrix alloy and TiCp/Al-Mg-Si composite by accumulative roll bonding (ARB), increasing yield strength from 380MPa to 443MPa with a uniform elongation from 5.0% to 6.4%, compared to the ARB TiCp/Al-Mg-Si composite.