کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
786459 1465611 2014 21 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
On the strength of dislocation interactions and their effect on latent hardening in pure Magnesium
ترجمه فارسی عنوان
بر روی قدرت تعامل جابجایی و تاثیر آن بر سختی نهانی در منیزیم خالص
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی مکانیک
چکیده انگلیسی


• Latent hardening coefficients are computed for hexagonal crystals from discrete dislocation dynamics.
• The validity of two commonly used hardening law is examined.
• The effect of friction stress and mobility on latent hardening coefficients is quantified.
• The effect of latent hardening on mechanical response is quantified.

This study is dedicated to the quantification of latent hardening and its effect on the plasticity of pure hexagonal magnesium. To this end, discrete dislocation dynamics simulations are used to (1) extract latent hardening parameters coupling different slip systems, and to (2) assess the validity of two existing constitutive models linking slip system strength to dislocation densities on all slip systems. As hexagonal materials deform via activation of different slip modes, each with different mobilities and lattice friction stress, the effects of the latter on latent hardening evolution are also investigated. It is found that the multi-slip formulation proposed by Franciosi and Zaoui gives accurate predictions when multiple interactions are involved while the formulation suggested by Lavrentev and Pokhil systematically overestimates the flow stress. Similar to FCC materials, it is also found that collinear interactions potentially contribute the most to latent hardening. Basal/pyramidal 〈c + a〉 interactions are found to be very strong, while interactions involving second-order pyramidal 〈c + a〉 primary dislocations appear to be the weakest ones. Finally, the latent hardening parameters, extracted from the discrete dislocation dynamics simulations, are used in polycrystal simulations and the impact of finely accounting for latent hardening on predictions of the macroscopic anisotropic response is shown to be of significant importance.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Plasticity - Volume 62, November 2014, Pages 72–92
نویسندگان
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