کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
828293 1470297 2015 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Tailoring a gradient nanostructured age-hardened aluminum alloy using high-gradient strain and strain rate
ترجمه فارسی عنوان
خم کردن یک آلیاژ آلومینیوم سخت شده با نانوساختار گرادیانت با استفاده از فشار و بار فشار بالا
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی (عمومی)
چکیده انگلیسی


• The topmost surface was shown nanostructured layer with greatly increased nanohardness.
• The role of strain and strain rate in grain refinement was quantitatively characterized.
• Nanograins were preferentially produced near precipitates at medium strains.
• Dislocation processes at sub-nanoscale level were observed.

Microstructural evolution of Al2024 alloy, consisting of precipitates, subjected to surface mechanical grinding treatment (SMGT) was investigated to reveal the role of strain and strain rate in structural refinement. Following SMGT, a gradient nanostructure was formed on the coarse-grained substrate, with a significant increase in nanohardness to over 1 GPa at the top surface. At low strains, the presence of particles and increasing strain rate stimulated the rapid transformation of dislocation configurations. However, at larger strains, increasing strain rate effectively stabilized the fine nanoscale structure. Strain gradient from the deformed layers and near the particles significantly promoted the development of microstructure by increasing the boundary misorientations, which was more significant at high strain rates. In particular, at very high rates and large strain gradients, extreme grain sizes may be induced. The presence of minority grains with size below 10 nm in the top 20-μm layers revealed that dislocation processes still operated at sub-nanoscale level. The dislocation-governed ductility was expected to be improved in the nanostructured materials.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials & Design - Volume 85, 15 November 2015, Pages 240–247
نویسندگان
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