A Physically Based Constitutive Model For Dynamic Strain Aging In Inconel 718 Alloy at a Wide Range of Temperatures and Strain Rates

Yooseob Song, The University of Texas Rio Grande Valley
George Z. Voyiadjis, Louisiana State University

© 2019 Springer Nature Switzerland AG. Original published version available at https://doi.org/10.1007/s00707-019-02508-6


Dynamic strain aging has a huge effect on the microstructural mechanical behavior of Inconel 718 high-performance alloy when activated. In a number of experimental researches, significant additional hardening due to the dynamic strain aging phenomenon was reported. A constitutive model without considering dynamic strain aging is insufficient to accurately predict the material behavior. In this paper, a new constitutive model for Inconel 718 high-performance alloy is proposed to capture the additional hardening, which is caused by dynamic strain aging, by means of the Weibull distribution probability density function. The derivation of the proposed constitutive relation for the dynamic strain aging-induced flow stress, the athermal flow stress and the thermal flow stress is physically motivated. The developed model is applied to Inconel 718 high-performance alloy to demonstrate its ability to capture the dynamic strain aging behavior, which was observed in the literature across a wide range of temperatures (300–1200 K) and strain rates from quasi-static loading (0.001/s) to dynamic loading (1100/s).