System and method for reducing grain boundaries in shrouded airfoils

Abstract

A turbine bucket includes an airfoil and a shroud. The shroud includes first and second bearing surfaces, and the first and second bearing surfaces each comprise a single grain structure. A method for forming a turbine bucket includes orienting a mold vertically, wherein the mold includes a first portion that defines a shank, a second portion connected to the first portion that defines an airfoil, and a third portion connected to the second portion that defines a shroud, wherein the third portion includes first and second sides, and wherein the first portion is higher than the second portion and the second portion is higher than the third portion. The method further includes flowing a molten metal into the mold and selectively growing large single grains in at least one of the first or second sides.

Dependencies are inferred from the claim text.