Vanadium-Induced Structural Effects on the Corrosion and Tribological Properties of an Al-Li Binary Alloy

Abstract

The influence of vanadium transition metal alloying on the structure, corrosion resistance and tribological properties of a binary Al-Li alloy containing 6wt% Li was investigated in this research. Varying vanadium contents of 0.05wt%, 0.1wt%, 0.5wt%, and 1.0wt% were examined. The results demonstrate that the addition of 1.0wt% vanadium optimally enhanced the corrosion resistance and wear resistance of the alloy. With 1.0wt% V, the wear rate decreased from 3.6 ± 0.50 ×10-2 m3/m to 1.5 ± 0.07 ×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 43.6µA/cm2 to 3.9µA/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 35µm to 8µm. 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 δ (AlLi) strengthening phase within the interdendritic regions, particularly with the addition of 1.0wt% V. The presence of this phase strongly contributed to the observed improvements in corrosion resistance and tribological properties of the vanadium-modified alloy.