Investigation of the Porosity Gradient in Thickness Direction Formed by Cold Rolling in Porous Aluminum

To adapt porous material for its application as low noise trailing edge, a special rolling process, using time-varied gap, was used in previous research to produce porosity gradient the direction of rolling. Investigations suggest that may also be produced thickness material, i.e., gap direction, without specialized mill. Such help further increase acoustic efficiency materials. The aim this study analyze dependency such on parameters, and clarify which stress components are significantly responsible an increased near-surface compaction. Experiments different relative compressed lengths were performed shear-dominated friction-dominated characterized compression tests, computed tomography flow resistance measurements. It is shown length important parameter adjusting gradient. Rolling with small values during all passes leads compaction regions, compared interior ones. difference achieved up 15%. Furthermore, results suggested hydrostatic Validation by FE simulation forthcoming, but not part publication.