کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4741343 1641482 2016 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of pressure on the strength of olivine at room temperature
ترجمه فارسی عنوان
تأثیر فشار بر مقاومت الیوین در دمای اتاق
کلمات کلیدی
اولیوین، رئوئولوژی، پلاستیکی کم دما، پراش اشعه ایکس، فشار بالا، پایرلز استرس، قدرت تولید
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فیزیک زمین (ژئو فیزیک)
چکیده انگلیسی


• We synthesized fully dense polycrystalline olivine by spark plasma sintering.
• An olivine aggregate was deformed at room temperature and between 3 and 7 GPa.
• We determined a low-T plasticity flow law incorporating a pressure dependence.
• The pressure dependence of the Peierls stress is larger than expected.
• A viscosity of 1023 Pa.s is predicted for cold subducting slabs at 100 km depth.

A fine grained fully-dense olivine aggregate was deformed in a D-DIA press at room temperature and pressures ranging from 3.5 to 6.8 GPa, at constant strain rates between 6×10-66×10-6 and 2.2×10-52.2×10-5 s−1. A weighted non-linear least square fit of a dataset including our results and data from other high-pressure studies to a low-temperature plasticity flow law yields a Peierls stress σP0=7.4(0.5) GPa and an activation energy E∗=232(60) kJ.mol−1. The dependence of the Peierls stress to pressure, σP=σP0(1+0.09P), appears to be larger than the value predicted by the formulation proposed by Frost and Ashby (1982). With such a dependence, the activation volume is very small (V*=1.6(1.7) cm3.mol−1). Extrapolation to natural conditions yields a viscosity of ~1023-1024~1023-1024 Pa.s for a cold subducting slab at depths of 50–100 km.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physics of the Earth and Planetary Interiors - Volume 259, October 2016, Pages 34–44
نویسندگان
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