期刊
JOURNAL OF ALLOYS AND COMPOUNDS
卷 610, 期 -, 页码 27-34出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.jallcom.2014.04.093
关键词
Aluminum alloy; Trialuminide compound; Coarsening; Precipitation strengthening
资金
- National Basic Research Program of China [2012CB619503]
- International Science & Technology Cooperation Program of China [2013DFB50170]
- National High Technology Research and Development Program of China [2013AA031301]
- National Natural Science Foundation of China [51101001, 51201003]
- Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry [40]
The aging strengthening behavior and coarsening process of Al3Er precipitates were investigated in AI-0.045Er (in at.%) alloys aged isothermally at 300-400 degrees C, using Vickers micro-hardness measurement and transmission electron microscopy (TEM) observation. The isothermal hardness curves showed that the peak hardness decreased slightly with the increase of temperature. From the TEM observations, the radius of Al3Er precipitates at peak hardness was measured to be 2.4 +/- 0.4 nm. The coherency of Al3Er precipitates started to get lost at the radius of 8.0-9.1 nm, which were much larger than the predicted value. The difference was speculated to be due the reduction of misfit between Al3Er precipitates and matrix when particles were very small. From the analysis of the coarsening of coherent Al3Er particles using LSW theory, the diffusion activation energy and the diffusivity pre-exponential constant of Er in Al were deduced to be 77.2 +/- 5.3 kJ/mol and (4.3 +/- 2.2) x 10(-12) m(2) S-1, respectively. Finally, the strength increment caused by Al3Er particles was evaluated using precipitation strengthening theory. It was found that when the particle radius was larger than 2.4 nm, the Orowan bypass mechanism dominated. In radius of 0-1.4 nm, a less coherency strengthening contribution indicated a reduction of lattice misfit between particles and matrix. From the strength plateaus in radius of 1.4-2.4 nm, the anti-phase boundary (APB) energy of Al3Er precipitates was deduced to be 0.60 +/- 0.03 J/m(2). (C) 2014 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据