Hot deformation processing of a precipitate free Ni-based superalloy

Description

Alloy 718 is a well-known nickel based alloy used for high temperature applications mainly in aerospace. This work describes the microstructure evolution due to thermomechanical treatment of a precipitate free IN718 (IN718 WP) produced by powder metallurgy. Therefore compression tests are performed by thermomechanical simulator Gleeble®-3800. Flow curves, grain size and recrystallization percentage are correlated with different temperatures and strain rates. Results show stress values up to 1.5 lower than standard alloy 718 and some common twinning features. The stress softening of the precipitation free material is comparable to standard alloy 718 for the high strain rates and almost twice larger at low strain rates. Dynamic recrystallization is observed in the deformed samples by means of light optical microscopy and SEM – EBSD. The size and percentage of recrystallization are correlated with the deformation parameters, i.e. with the temperature and strain rate. The material is fully recrystallized only after deformation at the lowest strain rates.

Period	21 Sept 2018
Event title	Advanced Materials Day 2018
Event type	Conference
Location	Graz, AustriaShow on map