Nickel-based superalloys exhibiting minimal grain defects

摘要: Carbide-forming elements are added to nickel-based superalloys so as minimize grain defects, such freckle and stray defects. More specifically, carbide-forming that form from the liquid in mushy zone of solidification front single crystal (SC) directionally solidified (DS) reduce formation defects alloys. A preferred superalloy includes, by weight, between about 6.00%-9.25% tantalum, 4.75%-6.50% tungsten, at least 2.75% rhenium, 5.00% 7.00% aluminum, 0.10% hafnium carbon an amount sufficient (typically 0.10-0.15% weight) carbides with other constituents significantly during casting.