A unified physically based constitutive model for describing strain hardening effect and dynamic recovery behavior of a Ni-based superalloy

Abstract

The strain hardening effect and dynamic recovery behavior of a Ni-based superalloy are studied by isothermal compressive tests. A new unified dislocation-density based constitutive model is developed to characterize the strain hardening effect and dynamic recovery behavior of the studied superalloy. In the developed constitutive model, some material parameters (yield stress, strain hardening coefficient, and dynamic recovery coefficient) are assumed as functions of initial grain size, deformation temperature, and strain rate. An iterative algorithm is designed to predict the high-temperature deformation behaviors under time-variant hot working conditions. The hot deformation parameters and material parameters can be updated in each strain increment. Comparisons between the experimental and calculated flow stresses indicate that the developed constitutive model can accurately describe the high-temperature deformation behavior of the studied superalloy. Furthermore, the developed constitutive model is also successfully used for analyzing time-variant hot working processes.

Study of Flow Softening Mechanisms of a Nickel-Based Superalloy With Δ Phase

“…where A ,n and α are the material constants, which can be evaluated by the procedure reported in previous studies [16,17]. In present study, the values of A ,n and α at the strain of 0.…”

“…In recent years, the hot deformation behaviors of some typical nickel-based superalloys were investigated. On the one hand, Lin et al [15,16,17], Kumar et al [18], Zuo et al [19], Yang et al [20], Azarbarmas et al [21], and Liu et al [22] developed various accurate constitutive models to predict the flow stress of some typical superalloys. Considering the synthetical effects of deformation temperature, strain, strain rate, and initial δ phase on the hot deformation behaviors of GH4169 superalloy, Lin et al [23,24] proposed the improved phenomenological constitutive model.…”

A new dynamic recrystallization kinetics model for a Nb containing Ni-Fe-Cr-base superalloy considering influences of initial δ phase

“…Lin et al [20,21,22] developed accurate phenomenological and physical-base constitutive models to predict high-temperature deformation behavior for GH4169 superalloy.…”

Simulation of the rheological behavior of the 01570C alloy under high-temperature deformation

“…During plastic deformation, free dislocations involved in plastic deformation are pinned by dispersoids or impurity atoms thus causing material hardening [5][6][7]. At the same time, at high temperatures, due to high mobility of dislocations, dynamic recovery occurs intensively, and this results in the annihilation of pinned dislocations and, as a consequence, in the reduction of the volume p V .…”