Influence of Heat Treatment on γ' Phase and Property of a Directionally Solidified Superalloy

摘要

The effects of heat treatment process on microstructure and properties of a nickel base superalloy are investigated. The size of γ' phase decreases and the stress rupture life of alloy at 1100 °C/60 MPa drops with the rise of cooling rate. The hardness at room temperature also increases. The size of cuboidal γ' precipitate and the volume of spherical γ' precipitate increase with the rise of aging temperature. With higher aging temperature, the alloy exhibits bimodal γ' phase. A reasonable combination of the size and volume fraction of cuboidal and spherical γ' phase can obtain better stress rupture property at 1100 oC/60 MPa.