Controlled Nano-Deposition of Metal On Cellular Foam Materials for Improved Energy Absorption Capacity

Cellular foam materials have been widely used in aerospace and automotive fields for a long time. One of these applications is energy absorption, primarily due to their unique stress-strain response. Because of this feature, cellular foams can be efficient structural enclosures for vehicles and buildings. A longer and higher plateau stress can further enhance the energy absorption capacity of cellular foams. Efforts have been made to provide reinforced cellular foams with improvement energy absorption capacity, but success has been limited. Meanwhile, nano-scale reinforcement strategies exhibit the potentials to provide superior mechanical properties over conventional through molecular level interactions both at interfaces and material continuum. In our study, open cell foams were reinforced at the nano-scale by stiffer metals to enable an enhanced energy absorption capability. Featured electrodeposition systems for direct and pulsed current were built up and with which the porous 3D cellular structure was successfully deposited. It is believed that the final energy absorption capacity will be a function of foam relative density, cell topology (pore size, ligament thickness, etc.) and processing conditions. The effects of pore size, coating thickness, strut thickness on energy absorption capacity have been systematically investigated and will be presented. And also, with same strut thickness, the advantage of applying deposition strategy will be shown by comparing the energy adsorption capacity of coated and uncoated Al foam.