Diffusion behavior and reactions between Al and Ca in Mg alloys by diffusion couples
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2018年第2期
论文作者：Jiahong Dai Hong Xiao Bin Jiang Hongmei Xie Cheng Peng Zhongtao Jiang Qin Zou Qingshan Yang Fusheng Pan
文章页码：291 - 298
摘 要：The diffusion behavior and reactions between Al and Ca in Mg alloys by diffusion couple method were investigated. Results demonstrate that Al2Ca is the only phase existing in the diffusion reaction layers.The volume fraction of Al2Ca in diffusion reaction layers increases linearly with temperature. The standard enthalpy of formation for intermetallic compounds was rationalized on the basis of the Miedema model. Al-Ca intermetallic compounds were preferable to form in the Mg-Al-Ca ternary system under the same conditions. Over the range of 350–400?C, the structure of Al2Ca is more stable than that of Al4Ca, Al14Ca13 and Al3Ca8. The growth constants of the layer Ⅰ, layer Ⅱ and entire diffusion reaction layers were determined. The activation energies for the growth of the layer Ⅰ, layer Ⅱ and entire diffusion reaction layers were（80.74 ± 3.01） k J/mol,（93.45 ± 2.12） k J/mol and（83.52 ± 1.50） k J/mol, respectively.In layer Ⅰ and Ⅱ, Al has higher integrated interdiffusion coefficients DInt, layerithan Ca. The average effective interdiffusion coefficients DAleff values are higher than DCaeff in the layer Ⅰ and Ⅱ.
Jiahong Dai1，Hong Xiao1，Bin Jiang2,3，Hongmei Xie1，Cheng Peng1，Zhongtao Jiang4，Qin Zou2，Qingshan Yang5，Fusheng Pan2,3
1. College of Mechanical and Electrical Engineering, Yangtze Normal University2. State Key Laboratory of Mechanical Transmissions, College of Materials Science and Engineering, Chongqing University3. Chongqing Academy of Science and Technology4. Research Institute for New Materials Technology, Chongqing University of Arts and Sciences5. School of Metallurgy and Materials Engineering, Chongqing University of Science and Technology
摘 要：The diffusion behavior and reactions between Al and Ca in Mg alloys by diffusion couple method were investigated. Results demonstrate that Al2Ca is the only phase existing in the diffusion reaction layers.The volume fraction of Al2Ca in diffusion reaction layers increases linearly with temperature. The standard enthalpy of formation for intermetallic compounds was rationalized on the basis of the Miedema model. Al-Ca intermetallic compounds were preferable to form in the Mg-Al-Ca ternary system under the same conditions. Over the range of 350–400?C, the structure of Al2Ca is more stable than that of Al4Ca, Al14Ca13 and Al3Ca8. The growth constants of the layer Ⅰ, layer Ⅱ and entire diffusion reaction layers were determined. The activation energies for the growth of the layer Ⅰ, layer Ⅱ and entire diffusion reaction layers were（80.74 ± 3.01） k J/mol,（93.45 ± 2.12） k J/mol and（83.52 ± 1.50） k J/mol, respectively.In layer Ⅰ and Ⅱ, Al has higher integrated interdiffusion coefficients DInt, layerithan Ca. The average effective interdiffusion coefficients DAleff values are higher than DCaeff in the layer Ⅰ and Ⅱ.
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