Vanadium-induced structural effects on the corrosion and tribological properties of an Al-Li binary alloy

The influence of vanadium transition metal alloying on the structure, corrosion resistance and tribological properties of a binary Al-Li alloy containing 6 wt % Li was investigated in this research. Varying vanadium contents of 0.05 wt %, 0.1 wt %, 0.5 wt %, and 1.0 wt % were examined. The results demonstrate that the addition of 1.0 wt % vanadium optimally enhanced the corrosion resistance and wear resistance of the alloy. With 1.0 wt % V, the wear rate decreased from 3.6 +/- 0.50 x 10-2 m3/m to 1.5 +/- 0.07 x 10-2 m3/m, the hardness increased from 51.7 +/- 7.3 HV to 77.6 +/- 4.1 HV, and the corrosion current density decreased from 43.6 mu A/cm2 to 3.9 mu A/cm2. Microstructural analyses revealed significant grain refinement induced by the addition of vanadium. The grain size decreased by 36.7 %, and the dendrite arm spacing (DAS) decreased from 35 mu m to 8 mu m. Adding vanadium reduced the overall porosity of the alloy resulting from a peritectic reaction leading to the formation of vacancy-solute complexes at the grain boundaries. Phase and chemical composition analyses confirmed the formation and presence of delta (AlLi) strengthening phase within the interdendritic regions, particularly with the addition of 1.0 wt % V. The presence of this phase strongly contributed to the observed improvements in corrosion resistance and tribological properties of the vanadium-modified alloy.