An initial assessment of the effects of increased Ni and V content in A356 and AA6063 alloys

Changes in calcined coke composition associated with different crude oil sources have caused nickel (Ni) and vanadium (V) levels in aluminum to rise. To ensure cast product quality is not compromised an understanding of the effects of these changes is needed. An initial investigation has been conducted for two commonly used alloys, A356 and AA6060/6063. Castings were produced with low typical levels of Ni-V and with high Ni-V levels approaching the maximum PI020 specification of 300ppm each. Micro-structural changes were assessed using optical and scanning electron microscopy and tensile properties and corrosion resistance were measured. For as-cast A356 alloy, there was no significant difference in corrosion performance, but adding Ni and V had a small effect on tensile properties. For AA6060/6063 alloy there was no significant difference in the tensile properties of extrusions with low and high Ni-V levels but a small drop in corrosion performance was measured at high Ni-V levels.