High resolution dataset of plastic deformation at cryogenic temperatures in a nickel-based superalloy

A nickel-based superalloy is examined during monotonic deformation at cryogenic temperatures, reaching as low as liquid helium temperature. A detailed multimodal analysis of the microstructure and plasticity is conducted to discern changes in deformation mechanisms and plastic deformation localization under cryogenic conditions. This study employs high-resolution digital image correlation to identify the deformation mechanisms and understand their influence on plastic deformation localization as the temperature varies. At cryogenic temperatures, unusual plastic deformation localization processes are observed, attributed to the competing activation of a range of deformation processes. Furthermore, a mechanism of slip delocalization, i.e., local plastic deformation homogenization through closely spaced slip, is noted at these extreme temperatures. Ultimately, the impact of the microstructure is identified across the temperature range, from room to cryogenic temperatures., Material: The present study investigated a nickel-based superalloy, Inconel 718. The Inconel 718 material was subjected to an annealing treatment at 1050◦C for 30 minutes, followed by water quenching to produce a nearly random texture and a grain size distribution centered at 65 μm. Subsequently, a two-step precipitation hardening treatment was performed by subjecting the material to 8 hours at 720◦C, followed by 8 hours at 620◦C. This treatment resulted in the formation of hardening γ’ and γ” precipitates.
Mechanical Testing: Flat dogbone-shaped specimens were prepared for testing with a gauge section measuring 1×3 mm2. The specimens were subjected to mechanical loading using an electromechanical 3R VHCF MEG20TT frame equipped with a custom setup for cryogenic testing. The specimens are exposed to either liquid helium or nitrogen pushed from a dewar using helium or nitrogen gas, respectively. The monotonic tensile tests were conducted at a quasi-static strain rate between 10−5 s−1 to 1..., , # High resolution dataset of plastic deformation at cryogenic temperatures in a nickel-based superalloy

[https://doi.org/10.5061/dryad.jm63xsjk3](https://doi.org/10.5061/dryad.jm63xsjk3)

## Methodological Information

**Material:** The present study investigated a nickel-based superalloy, Inconel 718. The Inconel 718 material was subjected to an annealing treatment at 1050◦C for 30 minutes, followed by water quenching to produce a nearly random texture and a grain size distribution centered at 65 μm. Subsequently, a two-step precipitation hardening treatment was performed by subjecting the material to 8 hours at 720◦C, followed by 8 hours at 620◦C. This treatment resulted in the formation of hardening γ’ and γ” precipitates.

**Mechanical Testing:** Flat dogbone-shaped specimens were prepared for testing with a gauge section measuring 1×3 mm2. The specimens were subjected to mechanical loading using an electromechanical 3R VHCF MEG20TT frame equipped with a custom setup for cryogenic ...