Prior Particle Boundary of PM FGH96 Superalloy and Its In-situ High-cycle Fatigue at Elevated Temperature

Abstract

The influence of different grades of prior particle boundary (PPB) in PM FGH96 superalloy during high-cycle fatigue test at 550 ℃ was investigated by the in-situ fatigue test in SEM. The results show that the PPB in P/M FGH96 superalloys by plasma rotating electrode process (PREP) + hot isostatic press (HIP) is constituted of large size γ' and carbide. There are no significant effect on the initiation and propagation of high cycle fatigue crack in different grades of PPB. Crack initiation is initiated in the grain interior, and the propagation is transgranular or intergranular, which is influenced by the angle between the grain boundary and the stress axis. In the fast crack growth zone and the transient zone, the fracture characteristics of serious grade PPB FGH96 superalloy are transgranular and along PPB globular surfaces.

Keywords

• P/M superalloy
• FGH96
• prior particle boundary
• <i>in-situ</i> fatigue