کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7979264 | 1514718 | 2015 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
TiB2 reinforced aluminum based in situ composites fabricated by stir casting
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In this study, a new technique involving mechanical stirring at the salts/aluminum interface was developed to fabricate TiB2 particulate reinforced aluminum based in situ composites with improved particle distribution. Processing parameters in terms of stirring intensity, stirring duration and stirring start time were optimized according to the microstructure and mechanical properties evaluation. The results show that, the first and last 15Â min of the entire 60Â min holding are of prime importance to the particle distribution of the final composites. When applying 180Â rpm (revolutions per minute) stirring at the salts/aluminum interface in these two intervals, a more uniform microstructure can be achieved and the Al-4Â wt% TiB2 composite thus produced exhibits superior mechanical performance. Synchrotron radiation X-ray computed tomography (SR-CT) was used to give a full-scale imaging of the particle distribution. From the SR-CT results, the in situ Al-xTiB2 composites (x=1, 4 and 7, all in wt%) fabricated by the present technique are characterized by fine and clean TiB2 particles distributed uniformly throughout the Al matrix. These composites not only have higher yield strength (Ï0.2) and ultimate tensile strength (UTS), but also exhibit superior ductility, with respect to the Al-TiB2 composites fabricated by the conventional process. The Ï0.2 and UTS of the Al-7TiB2 composite in the present work, are 260% and 180% higher than those of the matrix. A combined mechanism was also presented to interpret the improvements in yield strength of the composites as influenced by their microstructures and processing history. The predicted values are in good agreement with the experimental results, strongly supporting the strengthening mechanism we proposed. Fractography reveals that the composites thus fabricated, follow ductile fracture mechanism in spite of the presence of stiff reinforcements.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 625, 11 February 2015, Pages 357-368
Journal: Materials Science and Engineering: A - Volume 625, 11 February 2015, Pages 357-368
نویسندگان
Fei Chen, Zongning Chen, Feng Mao, Tongmin Wang, Zhiqiang Cao,