Study on the Compression Properties and Deformation Failure Mechanism of Open-Cell Copper Foam

Uniaxial compression experiments on open-cell copper foams are conducted at strain rates of 10(-2)s(-1), 10(-3)s(-1), and 10(-4)s(-1) to obtain the true stress-strain curves. The effects of the strain rate, cell size, and porosity on the mechanical properties is studied. The deformation mechanism of the open-cell copper foams is investigated by experimental research and finite element analysis. The results showed that the compression strength, Young's modulus and yield strength increase with increasing strain rate and decreasing porosity and cell size. A lower strain rate results in higher strain sensitivity. Strain-hardening behavior occurred in the process of high-strain-rate loading. The experimental and simulation results indicate that the failure mechanism of the open-cell copper foam is the layer-by-layer collapse failure mechanism and that stress concentrations form easily at the weak pore struts. The simulation results are consistent with the experimental data at the first and second stages. However, the value of true stress predicted by the simulation at the third stage is slightly higher than that of the experiments.