کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7983751 | 1514783 | 2013 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effects of Cu and Ag additions on age-hardening behavior during multi-step aging in Alî¸Mgî¸Si alloys
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
دانش مواد (عمومی)
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Low Cu and Ag additions (â¤0.10 at%) were found to strongly affect the age-hardening behavior in Alî¸Mgî¸Si alloys with Mg+Si>1.5 at%. The hardness increased during aging at 170 °C and the formation of βⳠprecipitates was kinetically accelerated. The activation energy of the formation of the βⳠphase was calculated to 127, 105, 108 and 99 KJmolâ1 in the base, Cu-added, Ag-added and Cuî¸Ag-added alloys, respectively using the Kissinger method. The negative effect of two-step aging caused by the formation of Cluster (1) during natural aging was not overcome by the addition of microalloying elements. However, it was suppressed by the formation of Cluster (2) through a pre-aging at 100 °C. Quantitative analysis of the precipitate microstructure was performed using a transmission electron microscope equipped with a parallel electron energy loss spectrometer for the determination of specimen thickness. The formation of Cluster (2) was found to increase the number density of βⳠprecipitates, whereas the formation of Cluster (1) decreased the number density and increased the needle length. The effects of low Cu and Ag additions in combination with multi-step aging are discussed based on microstructure observations and hardness and resistivity measurements.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: A - Volume 560, 10 January 2013, Pages 154-162
Journal: Materials Science and Engineering: A - Volume 560, 10 January 2013, Pages 154-162
نویسندگان
JaeHwang Kim, Calin Daniel Marioara, Randi Holmestad, Equo Kobayashi, Tatsuo Sato,