Effect of stress on μ phase formation in single crystal superalloys

Precipitation behavior of the μ phase under applied stress was systematically investigated in two single crystal superalloys CMSX-4 and R0. The investigation has shown that both the sign and magnitude of the applied stress can affect the precipitation behavior of the μ phase with a certain degree of regularity. At first, the precipitation of the μ phase varied significantly when a small amount of stress was applied, regardless of whether the specimen is under tension or under compression. Under most conditions however, precipitation of the μ phase was restrained by this low application of stress. After increasing the applied stress, precipitation of the μ phase increased relative to the amount of tension or decreased under compression.