Compression fatigue properties of open-cell aluminum foams fabricated by space-holder method.

Highlights • The fatigue mechanism was analyzed from macroscopic to microscopic scales. • Effect of porosity on fatigue performance of Al foams was investigated. • The deformation process under quasi-static and cyclic compression was comparatively analyzed. Abstract The compression-compression fatigue properties of open-cell Al foams fabricated by space-holder method with different porosities were investigated. The ε–N curves of the Al foams show two types based on the stress levels (k). The first type shows a three-stages for low stress level (k < 0.9), while the second type only presents stage I and stage III for high stress level (k ≥ 0.9). The quasi-static compression tests were performed to determine the yield strength (σ s) of Al foams. The fatigue strengths of Al foams with porosities of 50%, 60% and 70% are 12.77 MPa (0.75 σ s), 7.61 MPa (0.68 σ s) and 3.02 MPa (0.66 σ s) respectively, showing a linear decrease with the increment of porosity. The macroscopic deformation observation shows that the local deformation regions during fatigue tests emerge earlier than those during quasi-static compression tests. The initiation and propagation of fatigue cracks are the main failure mechanism of Al foams subjected to compression fatigue loading. [ABSTRACT FROM AUTHOR]