Low-temperature superplastic deformation of EK61 and EP975 wrought nickel-based superalloys with an ultrafine-grained structure

It is shown that thermomechanical treatment (TMT) of the EK61 superalloy with a strain rate (ε∙) 10−3 s−1 and gradual decrease in temperature from (0.92 – 0.65)Tδ leads to transformation initial coarse-grained structure into an ultrafine-grained (UFG) mixed type structure. Such UFG microstructure consists γ-phase grains δ-phase particles 0.3 μm size relatively large up 2 size. The having such exhibits low-temperature superplasticity range 700 900°C, maximum characteristics which are achieved at 850°C ε∙ =10−3 s−1. Low-temperature TMT (0.84 0.8)Тγ' also formation EP975 superalloy. γ'-phase 0.5 And there 3.5 globular-shaped form. 900 –1000°C, 1000°C