کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7990639 | 1516130 | 2018 | 22 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Phase selection and mechanical properties of permanent-mold cast Mg-Al-Ca-Mn alloys and the role of Ca/Al ratio
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In this work, phase selection, microstructure and mechanical properties of Mg-Al-Ca-Mn alloys with three different Ca/Al ratios (0.58, 0.79 and 0.91) were studied. The Mn content of the alloys was kept constant at â¼0.30â¯wt%. Thermodynamic non-equilibrium (Scheil) simulations, X-Ray Diffraction (XRD) analyses and Scanning Electron Microscopy/Electron Dispersive Spectroscopy (SEM/EDS) determined that all three alloys contain α-Mg solid solution phase, Al8Mn5 intermetallics and, depending on the Ca/Al ratio, combinations of C36-(Mg,Al)2Ca (hP24 aâ¯=â¯0.577-0.586â¯nm, câ¯=â¯1.819-1.835â¯nm), binary C14-Mg2Ca (hP12, aâ¯=â¯0.620â¯nm câ¯=â¯1.023â¯nm), ternary C14-Mg2Ca (hP12, aâ¯=â¯0.561-0.599â¯nm, câ¯=â¯1.025-1.051â¯nm), and/or C15-Al2Ca (cF24, aâ¯=â¯0.793â¯nm) Laves phases. It is observed that Ca/Al ratio shows a direct relationship with the total amounts of Laves intermetallics and the amount of the C36 phase, and an indirect relationship with the amount of C14 phase. Microhardness measurements, room and elevated temperature (150â¯Â°C and 200â¯Â°C) tensile tests, as well as tensile creep tests (175â¯Â°C/50â¯MPa), were carried out to determine the mechanical properties of the alloys. Results show that the hardness and room temperature yield and ultimate tensile strengths (UTS) increase while the ductility at all temperatures decreases with increasing Ca/Al ratio. At elevated temperatures, in the range of Ca/Al ratios investigated, the UTS has a relationship with the dissolved amount of Ca and Mn in the α-Mg phase. Creep strain was found to decrease from 0.35% to 0.05% as Ca/Al increases from 0.6 to 0.9 and as the amount of the C36 phase which can strengthen grain boundaries increases. One order of magnitude improvement seen in creep resistance as the Ca/Al ratio increases from 0.6 to 0.8 is attributable to the presence of C36 and C14 phases rather than C36 and thermally unstable C15 phase in the alloys and to the increased amounts of dissolved Mn and Ca in the α-Mg matrix.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 764, 5 October 2018, Pages 216-225
Journal: Journal of Alloys and Compounds - Volume 764, 5 October 2018, Pages 216-225
نویسندگان
Hamid Ali Elamami, Alper Incesu, Konstantinos Korgiopoulos, Mihriban Pekguleryuz, Ali Gungor,