کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5456424 1514661 2017 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ageing behavior of as-cast SiCp/AZ91 Mg matrix composites
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
Ageing behavior of as-cast SiCp/AZ91 Mg matrix composites
چکیده انگلیسی
SiC particles exhibited necklace-type distribution in SiCp/AZ91 Mg matrix composites fabricated by stir casting, and thus, the SiC particles could be divided into segregated particles region and particle free region. The effects of this particle distribution on the discontinuous precipitation of Mg17Al12 phase during ageing were investigated. The high density dislocations were induced due to the sharp mismatch between the thermal expansion coefficients of SiC and AZ91 alloy. The overlapped mismatch among the segregated particles causes higher density dislocations. And as a result, the discontinuous precipitations as the ageing products started born mainly near particles, especially near segregated particles. However, few Mg17A112 precipitated in the matrix within the particle segregation. The high-density dislocations and the numerous SiC/Mg interfaces made Mg17A112 phases much easier and earlier to precipitate in the composite. Thus, the SiCp addition reduced the peak ageing time from 38 h (for AZ91 alloy) to 28 h (for the composite). The ultimate tensile strength of the composite was enhanced by 46% after peak-ageing. SiC particles could also improve the age hardening efficiency of the composite because the high-density dislocations, the fine grain sizes and the numerous SiC/Mg interfaces cause the finer and more uniform precipitation of Mg17A112 Above all, the addition of SiC particles is effectively to improve the mechanical properties of magnesium matrix composite materials.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 682, 13 January 2017, Pages 491-500
نویسندگان
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