2024铝合金冷轧板材的中子衍射织构表征与力学性能分析

Neutron Diffraction Texture Measurement and Mechanical Property Study of Cold Rolling 2024 Aluminum Alloy Sheet

2024铝合金是Al-Cu-Mg系铝合金的代表材料,在航空航天领域有重要应用,其力学性能受到晶粒择优取向(织构)的影响。本研究利用中子衍射与电子背散射(EBSD)技术表征了不同冷轧变形量下2024铝合金板材的晶粒形貌与取向分布,基于拉伸实验进行了特征力学性能测试,研究了织构与力学性能的关联性。拉伸试验结果表明板材沿轧向方向屈服强度最优,沿与轧向呈45°方向延伸率最优;通过中子衍射测得{111}极图定性分析了板材沿宏观方向力学性能变化趋势,结果与拉伸测试结果一致。研究表明,相对于EBSD,中子衍射能更好表征粗晶粒材料中晶粒取向的分布,反映材料体织构,从而可用于定性判断其力学性能,为优化材料工艺、提高服役性能提供有效支撑。

2024 aluminum alloy(AA2024)is known as the representative material of Al-Cu-Mg aluminum alloy,which has generally applicated in aerospace field.Preferred orientation(texture)could profoundly affect the mechanical properties of the material.Neutron diffraction and EBSD were used in this study for the characterization of grain morphology and orientation on AA2024 sheets with different cold rolling deformation rates.Mechanical tests show that the yield strength along rolling direction remains optimization,while the 45°direction to rolling direction has the best elongating performance.Furthermore,analysis of{111}pole figures from neutron diffraction shows the consistency with the evolution of the mechanical properties.Research shows that neutron diffraction measurement can more accurately obtain macro distribution of grain orientation compared with EBSD,particularly while coarse grains obviously exist in the material.It can be concluded that neutron diffraction texture analysis can illustrate spatial distribution of grains,and the application of this method can effectively support the optimum of manufacturing process and improvement of service performance.