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Effects of Adiabatic Heating and Strain Rate on the Dynamic Response of a CoCrFeMnNi High‑Entropy Alloy

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Details

Original languageEnglish
Pages (from-to)320-330
Number of pages11
JournalJournal of Dynamic Behavior of Materials
Volume5
Issue number3
DOIs
Publication statusE-pub ahead of print - 30 Jul 2019
Publication typeA1 Journal article-refereed

Abstract

This work presents a comprehensive analysis of the effects of strain and strain rate on the adiabatic heating and the mechanical behavior of a CoCrFeMnNi high-entropy alloy (HEA). In this investigation, compression tests were carried out at quasi-static and dynamic strain rates. The temperature of the specimens was measured using high speed infrared thermography. The high strain rate tests were conducted with a Split Hopkinson Pressure Bar, and the tests at lower strain rates were performed using a universal testing machine. The material exhibited a positive strain rate sensitivity, as true stress–strain plots were shifted upwards with the increase in strain rate. With exception of the isothermal tests, temperature rise and the Taylor–Quinney coefficient (β) were noticeably similar for the investigated strain rates. This study shows that the common assumption that β can be considered 0.9 and constant is possibly not very accurate for the CoCrFeMnNi alloy. The β is influenced by at least strain and strain rate.

Keywords

  • Adiabatic heating, Taylor–Quinney coefficient, CoCrFeMnNi, High-entropy alloy, Dynamic testing, High speed infrared imaging

Publication forum classification

Field of science, Statistics Finland