Tracking Hydrogen Microporosity Evolution During Solidification of Al-Cu-Li Alloy Using Multiscale Model and Synchrotron Radiation X-ray Radiography

In-situ observations of the evolution of hydrogen microporosity nucleation and growth during solidification of Al-Cu-Li alloys were conducted by using synchrotron X-ray radiography. The kinetic behavior of hydrogen microporosity and the mechanisms of nucleation and growth were investigated and verified by comparison with a multiscale model. Hydrogen microporosity was found to nucleate at temperatures between 610 degrees C and 622 degrees C during solidification and exhibited rapid growth between 565 degrees C and 610 degrees C, with growth rates around 3.2 mu m/s. The evolution of hydrogen microporosity growth was best described by the Boltzmann function and displayed merging and ripening behavior. The average equivalent diameter (D<overline>e\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\overline{D} }_{e}$$\end{document}) of hydrogen microporosity and hydrogen supersaturation (SSH) followed the relationship D<overline>e\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\overline{D} }_{e}$$\end{document}=23.96SSH-0.27. The evolution of 3D hydrogen microporosity during the solidification of Al-Cu-Li alloy was predicted by using a multiscale model. Simulation results agreed well with in-situ experiments, offering a predictive tool for optimizing the manufacturing process of Al-Cu-Li alloy products.