| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Mechanisms of Shock Strength Exhibited by a Nickel-Rich Nickel-Titanium-Hafnium Alloy |
| Author(s) |
Tyler D. Knapp, Aaron Stebner |
| On-Site Speaker (Planned) |
Tyler D. Knapp |
| Abstract Scope |
Ni-rich NiTiHf alloys exhibit very high strengths and good quasi-static indentation resistance and rolling contact fatigue performances. To determine whether these properties are maintained at high rates of loading, in-situ and recovery flyer plate impact shock experiments were performed on a Ni54Ti45Hf1 alloy at impact velocities ranging from approximately 150 (2.5 GPa) to 700 m/s (12.40 GPa). Analysis of Ni54Ti45Hf1 samples indicated less cracking was observed to emanate from spall failures resulting from impact velocities greater than 250 m/s (4.23 GPa), concurrent with observations of intragranular microbands. Analyses of the mechanical responses showed clear evidence that martensitic phase transformation occurred upon shock compression and reversed upon stress release, yet analyses of these microbands showed no evidence for retained martensite and that nanoprecipitates within the microbands dissolved. These results show that strain-rate dependence of these SMAs under shock loading are not only governed by expected physics of rate-dependence of the martensitic transformations themselves, but also enhanced by plastic deformation mechanisms that result in precipitate dissolution. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Phase Transformations, Mechanical Properties, Other |