Effect of Near Immersion Active Cooling Technology on the Formation and Microstructure of Directed Energy Deposition-Arc Inconel 718 Alloy
摘要
This article studies the formation and microstructure of directed energy deposition-arc Inconel 718 alloy assisted by near immersion active cooling technology (NIAC). The results indicate that, NIAC increases the cooling rate through water heat conduction, shortens the solidification time of the molten metal, suppresses the overflow phenomenon, and significantly reduces the surface roughness (358 μm→252 μm). The increase in the cooling rate leads to the growth of subcooling, which improves the driving force for nucleation and reduces the average grain size. In addition, the increase in cooling rate also suppresses the segregation of Nb, greatly reduces the size of the Laves phase, and the Laves phase area fraction reduces from 5.4 to 1.9%.
Graphical Abstract