Density-Graded Aluminum Foams by the Corrosion Method
Optimum corrosive density-grading of T6- and solution-treated alloys was studied using NaOH solutions. Rough corroded strut surfaces in aluminum foams were found to transform to smooth metallic surfaces with an increase in pH from 10 to 13. For instance, during immersion in pH13 solutions, pits with large curvatures appeared on strut surfaces, and corrosive mass losses increased. Strut diameters also decreased, and open cell windows became wider, without an increase in visible damage. Processing parameters such as pH, corrosion rate, and the surface state of the struts were examined to optimize final structure. An experimental method for grading of relative density continuously between 10% and 5% is described.
T. Chandra, K. Tsuzaki, M. Militzer , C. Ravindran
Y. Matsumoto et al., "Density-Graded Aluminum Foams by the Corrosion Method", Materials Science Forum, Vols. 539-543, pp. 1903-1908, 2007