Directionally solidified columnar grained article and apparatus for manufacture thereof

摘要

A method and an apparatus for manufacturing a directionally solidified columnar grained article with a reduced amount of secondary misorientation of the columnar grains. The method employs a casting assembly comprising a mold with a cavity, a selector section at a lower end of the mold, a heating chamber and a cooling chamber. The mold is fed with a liquid metal and moved from the heating chamber to the cooling chamber where the columnar grained article is solidified. The article is solidified with at least two dendrites or grains emerging from the selector section and entering the main cavity of the shell mold. Further, the selector section is configured so that no dendrite or grain grows from the bottom of the selector section into the shell mold cavity along a continuous path of purely vertical growth.