Author:
Mukhtarov Sh,Shakhov R,Ganeev A
Abstract
Abstract
The microstructure evolutions of the cast rhenium containing nickel-based superalloy subjected to thermomechanical treatment and severe plastic deformation by high pressure torsion were investigated. Thermomechanical treatment led to the formation a fine-grained structure with γ grain size of about 7 μm and both large precipitates of the γ’ phase with a size of 1-5 μm and dispersed precipitates with a size of about 0.2 μm. Microstructure of the superalloy subjected to high pressure torsion up to 5 revolutions was nanocrystalline with partly dissolved of the dispersed γ′ precipitates. The effect of different kinds of deformation and subsequent annealing on the microstructure, grain boundaries and microhardness changes are also discussed.