Microscopic stresses in carbon nanotube reinforced aluminum matrix composites determined by in-situ neutron diffraction
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第19期
论文作者：X.X.Zhang J.F.Zhang Z.Y.Liu M.Hofmann H.Andr? B.L.Xiao Z.Y.Ma
文章页码：58 - 68
摘 要：One of the most desired strengthening mechanisms in the carbon nanotube reinforced aluminum matrix composites（CNT/Al） composites is the load transfer strengthening mechanism（LTSM）. However, a fundamental issue concerning the LTSM is that quantitative measurements of load partitioning in these composites during loading are very limited. In this study, in-situ neutron diffraction study on the tensile deformation of the 3 vol.% CNT/2009 Al composite and the unreinforced 2009 Al alloy was conducted. The{311} and {220} diffraction elastic constants（DECs） of the 2009 Al alloy were determined. Using those DECs the average stress in the 2009 Al matrix of the composite was calculated. Then the average stress in the CNTs was separated by using the stress equilibrium condition. Computational homogenization models were also applied to explain the stress evolution in each phase. Predicted results agree with experimental data. In the present case, the average stress in the CNTs reaches 1630 MPa at the yield strength of the composite based on linear regression of the measured data, which leads to an increment of yield strength by about 37 MPa. As the result of this work, an approach to quantify load partitioning in the CNTs is developed for the CNT/Al composites, which can be applied to optimize the mechanical properties of the composites.
X.X.Zhang1，J.F.Zhang1，Z.Y.Liu1，M.Hofmann3，H.Andr?4，B.L.Xiao1，Z.Y.Ma1
1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences3. Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universit?t München4. Fraunhofer Institute for Industrial Mathematics
摘 要：One of the most desired strengthening mechanisms in the carbon nanotube reinforced aluminum matrix composites（CNT/Al） composites is the load transfer strengthening mechanism（LTSM）. However, a fundamental issue concerning the LTSM is that quantitative measurements of load partitioning in these composites during loading are very limited. In this study, in-situ neutron diffraction study on the tensile deformation of the 3 vol.% CNT/2009 Al composite and the unreinforced 2009 Al alloy was conducted. The{311} and {220} diffraction elastic constants（DECs） of the 2009 Al alloy were determined. Using those DECs the average stress in the 2009 Al matrix of the composite was calculated. Then the average stress in the CNTs was separated by using the stress equilibrium condition. Computational homogenization models were also applied to explain the stress evolution in each phase. Predicted results agree with experimental data. In the present case, the average stress in the CNTs reaches 1630 MPa at the yield strength of the composite based on linear regression of the measured data, which leads to an increment of yield strength by about 37 MPa. As the result of this work, an approach to quantify load partitioning in the CNTs is developed for the CNT/Al composites, which can be applied to optimize the mechanical properties of the composites.
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