کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
786428 1465604 2015 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Creep behavior as dislocation climb over NiAl nanoprecipitates in ferritic alloy: The effects of interface stresses and temperature
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی مکانیک
پیش نمایش صفحه اول مقاله
Creep behavior as dislocation climb over NiAl nanoprecipitates in ferritic alloy: The effects of interface stresses and temperature
چکیده انگلیسی


• Present dislocation climbing model for creep deformation to estimate theoretically.
• Threshold stress improves as temperature drops.
• Threshold stress rises with increasing average nanoprecipitate radius.
• The smaller precipitate size causes the more significant effect of interface stress.
• The positive (negative) interface stress relaxes (rises) creep activation energy.

Based on creep mechanism of lattice self-diffusion controlled dislocation climb process in the high temperatures range (873–923 K), dislocation climb model for creep deformation is presented with elastic interaction of climbing lattice dislocation with coherent nanoprecipitate to estimate theoretically the temperature and size dependence of creep behavior in NiAl nanoscale precipitation-strengthened ferritic alloy. The significant factors governing creep threshold stress and activation energy are evaluated quantitatively, such as temperature, nanoprecipitate size and interface effect as well as the mismatch between nanoprecipitate and matrix. The results show that creep rate data obey a good power-law dependence on applied stress with stress exponent of 4. In the temperature region investigated threshold stresses ranging from 0.4 to 0.5 σO and creep activation energies from 260 to 300 kJ/mol are evaluated, which are reasonable for characterizing the power-law dislocation creep mechanism. Model predictions presented in this work show good agreement with experiments for this ferritic Fe–Cr–Ni–Al alloy.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Plasticity - Volume 69, June 2015, Pages 89–101
نویسندگان
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