Investigation of Strain-Rate Effects in Ni/PU Hybrid Foams under Low-Impact Velocities

Abstract

Metal foams are often used as energy absorbers and lightweight materials. Inspired by a natural blueprint, open-cell metal foams can significantly reduce the mass of a structure. The innovative manufacturing process of electrodeposition provides the possibility to customize the coating layer thickness of nickel (Ni) on a polyurethane (PU) precursor foam. Consequently, the mechanical properties can be adjusted according to the requirements of the expected application. Herein, quasistatic compression tests and low-velocity impact tests are conducted on open-cell Ni/PU hybrid foams to investigate the strain-rate effects for strain rates in the range of 10−3 to 550 s−1. Furthermore, digital image correlation is performed with the intention of comparing the micromechanical deformation mechanisms under quasistatic loading with those under dynamic loading. For the first time, the heat evolution at different impact velocities of metal foams has been investigated with an infrared camera.