Anisotropy and strain localization in steel foam

Steel foam fabricated by a powder metallurgical process was tested in uniax ial compression. The closed-cell foam samples exhibited anisotropy in compr ession, a phenomenon that was caused primarily by the ellipsoidal cell shap es within the foam. Yield strengths were 3 x higher in the transverse direc tion than in the longitudinal direction. Yield strength also showed a power -law dependence on relative density (n congruent to1.8). Compressive strain was highly localized and occurred in discrete bands that extended transver se to the loading direction. The deformation hands were comprised of collap sed cells, and deformation occurred in a sequential manner with repeating c ycles of yield, collapse and densification of cells. Foam densification com menced when all of the foam was converted into deformation bands. (C) 2001 Elsevier Science B.V. All rights reserved.