Influence of reaction temperature for the manufacturing of Al–3Ti and Al–3B master alloys

Abstract

In the present work, binary Al–3Ti and Al–3B master alloys were prepared at different reaction temperatures in an induction furnace by the reaction of halide salts like potassium fluoborate and potassium titanium fluoride with liquid molten Al. The reaction temperatures of 800, 900 and 1000°C were selected while the reaction time was kept constant at 60min for the preparation of master alloys. These master alloys were characterized by chemical analysis, particle size analysis, XRD and SEM/EDX studies. The indigenously developed master alloys were used for grain refinement studies of Al–7Si alloy and evaluated for their grain refining ability by CA-CCA studies. The present results suggest that, the reaction temperature influences the size, size distribution and morphology of the intermetallic (Al3Ti in Al–3Ti and AlB2/AlB12 in Al–3B) particles present in Al–3Ti and Al–3B master alloys. Grain refinement studies of Al–7Si alloy reveal that, Al–3Ti and Al–3B master alloys prepared at 800°C–60min have shown better grain refining efficiency on Al–7Si alloy when compared to the master alloys prepared at 900°C–60min and 1000°C–60min, respectively. In addition, B-rich Al–3B master alloy shows efficient grain refinement than Ti rich Al–3Ti master alloy.