Mold with starter and selector sections for directional solidification casting

Abstract From the Canadian patent

19-, Abstract, Directional solidification of a single crystal superalloy article may be accomplished using a mold with a starter section, and a selector section to convert columnar growth from the starter into single crystal growth. In such a process the devia-, tion of 001 crystallographic orientation with respect to the longitudinal axis of the article being formed is reduced from 9 degrees to 5 degrees by controlling the heat transfer in the starter section. A stepped starter section wherein the lower subsection, has a volume of 52-98% of the total starter volume and wherein the upper subsection is relatively small in lateral dimension, has been found most useful. When the solidification …