Experimental and numerical analysis of the Portevin–Le Chatelier effect in a nickel-base superalloy for turbine disks application

High-pressure turbine disks are subjected to extreme mechanical and thermal loadings throughout their lifetime. This is the reason why during design of turboshaft engines, regulation rules impose on manufacturers demonstrate integrity rotating parts, especially disks, with over-speed experiments. To improve prediction rotation speed at burst, it essential study viscoplastic behavior fracture material. The present work focuses approach used calibrate accurately a model high temperature (500 °C) nickel-based superalloy Inconel718. experimental testing campaign includes standard tensile tests axisymmetric flat specimens without notches. described using McCormick for dynamic strain aging. accounts including range negative rate sensitivity Portevin–Le Chatelier (PLC) effect. In addition global measurements, digital image correlation speckle directly engraved specimen detect measure carried by PLC bands. information in parameter calibration. consideration machine stiffness shown be analysis correct description serrations critical effects. 3D simulations full geometries samples performed validate finite element model. Finally, representative disk geometry simulation instabilities propagation due geometrical singularities.