Effect of a Chloride Flux on the Dissolution of Mn-Al Compacts in Molten Aluminum

Dissolution and recovery of Mn-Al compacts with and without a chloride flux was studied by taking samples from the melt after addition of the compact. Events occurring after the addition of the compacts into the melt were studied using water quenched specimens after holding them for a specified time in molten state. The cross sections of these specimens were characterized by SEM as well as optical imaging. The results showed that an optimized amount of flux (10 to 15%wt. in this research) considerably decreases the time to reach more than 90% recovery in comparison with non-fluxed compacts. The flux caused the intermetallic forming reactions to be started considerably sooner in fluxed compacts in comparison with the non-fluxed compact. Consequently, the incubation time decreased from about 180 seconds for non-fluxed compacts to less than 3 seconds for compacts with 10%wt. flux