Shock-induced deformation twinning in tantalum
- Univ. of Texas, El Paso, TX (United States). Dept. of Metallurgical and Materials Engineering
- Univ. of California, San Diego, La Jolla, CA (United States). Dept. of Applied Mechanics and Engineering Sciences
Shock-wave deformation of tantalum to a pressure of 45 GPa and duration of 1.8 {micro}s generates profuse twinning. The post-shock mechanical response is significantly affected, with shock hardening exceeding the expected hardening due to the transient shock strain {epsilon}{sub s} = (4/3)ln(V/V{sub 0}); this enhanced hardening, and other alterations in response, are attributed to the barriers presented to plastic deformation by the deformation twins. A constitutive model is proposed that predicts the threshold shock stress for mechanical twinning; it is based on the application of the Swegle-Grady relationship between shock stress and strain rate to constitute equations describing the critical stress for slip and twinning. This constitutive model incorporates grain-size effects and predicts a threshold twinning stress that is a function of temperature and grain size; predictions of the model are in qualitative agreement with experimental results.
- OSTI ID:
- 445332
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 1 Vol. 45; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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