Thermomechanical fatigue of open cell aluminium sponge
The aim of this paper is to present experimental and simulation results to understand the mechanical behaviour of the open-cell AlSi7Mg sponge under monotonic and cycling loading conditions placing particular attention to thermomechanical fatigue (TMF) and creep characteristics. Uniaxial compressive and tensile tests were carried out taking into account variation in the homogeneity and ductility of the aluminium sponge. It has been observed that the effect of the relative low ductility of the material causes brittle behaviour during monotonic tensile testing. Furthermore, a strong decrease in the stiffness in the tensile part of the stress-strain hysteresis loop was observed under fully reversed fatigue loading. This could be attributed to the pronounced damage accumulation due to cracking of cell struts. Contrary to isothermal testing, TMF conditions lead to mean stresses since the variation in temperature causes different values of the yield strength in tension and compression.