Hot Deformation Behavior and Constitutive Modeling of a Novel Ni-Based Superalloy

Abstract

AbstractNi-based superalloys are widely used to manufacture the key components of a gas turbine engine because of their superior mechanical properties at elevated temperatures. In the present work, the hot deformation behavior of a novel Ni-based superalloy was investigated by compression test at temperatures of 1020–1140 °C and strain rates of 0.001–10 s−1. At low temperature and high strain rates, the flow stress rapidly increased to a peak value due to work hardening. However, at high temperatures and low strain rates, the flow curves exhibited a typical dynamic softening stage. The hot deformation activation energy of the studied superalloy is determined to be 735.4961 kJ/mol, and a strain-compensated Arrhenius-type constitutive equation is obtained. On comparing the predicted and experimental values, the developed constitutive equation can accurately describe the deformation mechanism and the flow behavior. Meanwhile, the influence of hot processing parameters on microstructure has been deeply explored, which can optimize the process parameters for manufacturing key components in gas turbine engine.KeywordsHot plastic deformationFlow behaviorConstitutive modelingMicrostructureNi-based superalloy