Study on Cell Deformation of Low Porosity Aluminum Foams under Quasi Static Compression by X Ray Tomography

Understanding the correlation between cell deformation and initial cell structure during compression is important for improvement and development of effective applications of aluminum foams. Foams with porosities lower than 75 now get more attention because of more spherical cells and better mechanical performance. Herein, two low porosity aluminum foam samples are deformed by a compressive device allowing simultaneous X ray tomography. The foam cell structures in the initial undeformed state and in the state, where the first batch of cells deforms, are characterized and correlated. The absolute value of anisotropy change is selected as the most sensitive parameter to evaluate the cell deformation. A fitting formula between the cell deformation degree and the initial cell parameters is obtained, which can predict the cell deformation degree. It is found that a cell with small anisotropy, large angle between the longest axis of the cell and the loading direction, small sphericity, more neighbors, and large cell size is more prone to deform during compression. With the fitting formula, the weakest region where the first batch of deformed cells occurs can be predicted. The influence of cell morphology parameters in low porosity aluminum foams is significant and verified by experimental result