Microstructure instability at surface of Ni-base superalloys during solution heat treatment

摘要

New insights into microstructure instability during heat treatment of Ni-base superalloy turbine blades have been investigated, with specific consideration to a 3rd generation Ni-base superalloy.Microstructure instability develops at the casting surface during heat treatment resulting in the formation of γ' surface layers.During solution heat treatment, elemental vaporisation occurs at the casting surface : Ni and Cr sublimate from the surface;and the resultant structures that form are dictated by re-distribution of Re.