Fatigue and cyclic creep of replicated microcellular aluminium

The cyclic behaviour of 400 μm pore size replicated aluminium foam is assessed in tension–tension fatigue with a stress ratio equal to 0.1, keeping the load amplitude constant, for relative density values comprised between 0.175 and 0.220. The number of cycles to failure ranges from 6 × 102 (lowest relative density) to 5 × 106 (highest relative density). The foams display cyclic creep coupled with a strong influence of relative density on their general fatigue performance. Data analysis shows that the foam fatigue behaviour is dominated by cyclic creep, which governs both the deformation and the fatigue life of the cycled specimens, yielding characteristics globally in line with what is expected knowing the metal making the foam.