The Effect of Melt Overheating on the Melt Structure Transition and Solidified Structures of Al-La Alloy

Abstract

Although the effect of overheating treatment on solidification is due to the liquid structure state, its nature and rule are still unclear. In this article, the effect of melt overheating on the melt structure transition and solidified structures of Al100−x La x alloys (x = 2, 3, 5) was mainly studied with resistivity and rapid solidification methods. The resistivity of liquid Al-La alloy increases with the temperature and La content, and it shows the linear and nonlinear changes successively. The corrosion resistance and hardness of melt-spun alloy improves with the increase in melt temperature and La content. These results indicate that the melt structure becomes homogeneous, dense, and disordered with the increase in melt temperature, and a temperature-induced liquid–liquid structure change occurs at 880–960°C. The homogeneous and dense melt structure features are remained partly in this melt-spun alloy and have a beneficial influence on its corrosion resistance and hardness. It is useful to study on the melt structure and solidified structures with the rapid solidification and resistivity method.