کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7992935 | 1516149 | 2018 | 40 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Mechanical behavior of nanostructured and ultra-fine grained Al containing nanoscale oxide particles processed via spark plasma sintering of nano-sized Al powders
ترجمه فارسی عنوان
رفتار مکانیکی آلومینیوم نانوساختار و آلومینیوم حاوی ذرات نانومقیاس اکسید که توسط اسپکتروفتومتری جوش با پودرهای آلومینیومی نانو
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کلمات کلیدی
مواد نانوساختار، مواد دانه ای فوق العاده خوب، پخت سیلر جرقه، پودر نانو استحکام، شکل پذیری،
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
چکیده انگلیسی
This paper reports a study on mechanical behavior during tensile testing of nanostructured (NS) Al and ultra-fine grained (UFG) Al containing nanoscale oxide particles that were produced via consolidation of nano-sized Al powders using spark plasma sintering (SPS) only and SPS plus extrusion, respectively. Our results show that the NS Al exhibits â¼370â¯MPa in 0.2% offset yield strength and â¼0.9% in elongation to failure, whereas the UFG Al presents â¼430â¯MPa in 0.2% offset yield strength and â¼1.5% and â¼1.9% in uniform elongation and elongation to failure, respectively. Based on the tensile stress vs. strain curves, microstructural features and fractured surface characteristics, mechanical behavior of NS Al and UFG Al was analyzed and discussed in detail. We suggest that the lower yield strength and ductility in the NS Al than those in UFG Al can be attributed to the strong stress concentration at grain boundaries (GBs) as a result of (i) the presence of highly segregated nanoscale oxide particles and of residual porosity at GBs to induce, and (ii) the absence of dislocation sources and thus of activated dislocation slip at nano-sized grain interiors (GIs) to release, the stress concentration. Immediately after yield in the as-SPSed Al, the stress concentration debonded GBs and further tensile straining rapidly led to connection between debonded GBs and the occurrence of intergranular fracture. In contrast, in the UFG Al the extent of oxide particle segregation and the porosity at GBs were reduced due to materials flow during extrusion, avoiding the occurrence of intergranular fracture at a very low strain level and thus sustaining plastic straining; as a result, yield strength and ductility were improved. However, the residual porosity and nano-sized/ultra-fine grains still induced early strain localization shortly followed by transgranular fracture via growth, coalescence and connection of nano-sized pores, leading to limited ductility.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 745, 15 May 2018, Pages 677-687
Journal: Journal of Alloys and Compounds - Volume 745, 15 May 2018, Pages 677-687
نویسندگان
Yaojun Lin, Zhigang Yan, Bocong Xu, Yongzhao Feng, Fei Chen,