Method of producing a single crystal article.

摘要

An improved method of producing a nickel-base single crystal superalloy cast article having a refined gamma prime phase disposed in a gamma phase matrix includes casting the single crystal article with a coarse gamma prime phase disposed in a gamma phase matrix. A stress concentration may be formed in a portion of the article. This stress concentration may be of sufficient severity to cause recrystallization upon heating of the single crystal article to a solution heat treatment temperature at which the gamma prime phase can go into solid solution in the gamma phase. To prevent recrystallization from occurring, the severity of the stress concentration is reduced by heating the single crystal article to a recovery temperature which is below the temperature at which recrystallization occurs. Thereafter, the article is solution heat treated to cause the gamma prime phase to go into solid solution with the gamma phase. A refined gamma prime phase is then precipitated in the gamma phase matrix while the single crystal structure of the article is maintained.