کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5354815 | 1503618 | 2015 | 34 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Study on the nanostructure formation mechanism of hypereutectic Al-17.5Si alloy induced by high current pulsed electron beam
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
This work investigates the nanostructure forming mechanism of hypereutectic Al-17.5Si alloy associated with the high current pulsed electron beam (HCPEB) treatment with increasing number of pulses by electron backscatter diffraction (EBSD) and SEM. The surface layers were melted and resolidified rapidly. The treated surfaces show different structural characteristics in different compositions and distribution zones. The top melted-layer zone can be divided into three zones: Si-rich, Ai-rich, and intermediate zone. The Al-rich zone has a nano-cellular microstructure with a diameter of â¼100 nm. The microstructure in the Si-rich zone consists of fine, dispersive, and spherical nano-sized Si crystals surrounded by α(Al) cells. Some superfine eutectic structures form in the boundary of the two zones. With the increase of number of pulses, the proportion of Si-rich zone to the whole top surface increases, and more cellular substructures are transformed to fine equiaxed grain. In other words, with increasing number of pulses, more Si elements diffuse to the Al-rich zone and provide heterogeneous nucleation sites, and Al grains are refined dramatically. Moreover, the relationship between the substrate Si phase and crystalline phase is determined by EBSD; that is, (1 1 1)Al//(0 0 1)Si with a value of disregistry δ at approximately 5%. The HCPEB technique is a versatile technique for refining the surface microstructure of hypereutectic Al-Si alloys.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 346, 15 August 2015, Pages 147-157
Journal: Applied Surface Science - Volume 346, 15 August 2015, Pages 147-157
نویسندگان
Bo Gao, Liang Hu, Shi-wei Li, Yi Hao, Yu-dong Zhang, Gan-feng Tu, Thierry Grosdidier,