Effect of denucleating glass composition on undercooling of Fe83Ga17 alloy melts

Adopting glass fluxing combined with superheating cycling method, the undercooling and its stability of Fe83Ga17 alloy melts were investigated using different kinds of denucleating glass: B2O3, 90% NaSiCa + 10% B2O3 (simplified as Na-Si-Ca-Al-B) and 70% Na-Si-Ca-Al-B + 30% Na2B7O4. The results showed that different glass has different denucleating mechanism. The purification of B2O3 glass is only a physical process, by which the stable bulk undercooling cannot be obtained during superheating-cooling cycles. While taking Na-Si-Ca-Al-B glass as purifying agent, its denucleating mechanism is a comprehensively physicochemical process. But the stability of undercooling is still undesirable because of the separation between melt and glass during cooling process in superheating cycling. A stable bulk undercooling can be obtained by physicochemical denucleating process in the case of 70% Na-Si-Ca-Al-B + 30% Na2B7O4 molten glass owing to its suitable viscosity.