Abatement of intergranular corrosion in zinc-aluminium foundry alloys through flux treatment

Commercial Zn-Al alloys are susceptible to Intergranular Corrosion (IGC) restricting their widespread use for various applications. In this paper the IGC behaviour of two important foundry alloys namely Zn-8Al and Zn-12Al has been studied through microstructural observations with a view to improving the resistance to intergranular attack. It has been shown that a special flux containing boric oxide along with fluoride and chloride salts employed during the preparation of the alloys significantly improves the resistance to intergranular attack.