The evolution of precipitation in the Ni-based superalloy AD730 during slow cooling from supersolvus temperatures and non-isothermal compression, conditions representing the early stages of the billet conversion process, is investigated. A range of different precipitate morphologies were observed and are shown in 3D using focused ion beam (FIB) serial sectioning and volumetric reconstruction. This 3D view reveals that precipitates which appear different in 2D sections may have the same morphology in 3D. 

The recrystallisation mechanisms occurring around different precipitate types are characterised, and the origin of primary precipitates is discussed.