Abstract
The grain refinement of aluminium alloys is one of the important processes in various industrial fields. This work aims to use aluminium-vanadium (Al-V) master alloy as a new grain refiner for grain refinement of aluminium alloys. The new refiner was prepared by reduction of vanadium pentoxide V2O5 using molten aluminium, then it was examined using SEM, EDS, XRD, and optical microscopy. The findings of these tests indicated that the developed master alloy contains blockyshaped particles evenly distributed within the aluminium matrix Al3V in the form of an intermetallic compound. Different levels of vanadium content were examined (3.5, 5.6, and 8.3) as grain refiners for commercial pure Al and 6063 alloys. It was found that the grain size was decreased from 2000 to 320 mu m for commercial pure aluminium and decreased from 1500 to 300 mu m for 6063 alloys. The best results were obtained by using vanadium content of 0.03 wt.% in the refined alloy and a holding time of 3 min. Based on the growth restriction factor (GRF), the new grain refiner Al-V master alloy performed well at vanadium contents more than 0.02 wt.% in the refined alloy.