Yielding of metallic glass foam by percolation of an elastic buckling instability

The preparation of metallic glass foam by percolation of an elastic buckling instability, was investigated. A 70 % porosity closed-cell amorphous Pd₃₄Ni₁₀Cu₂₇P₂₀ foam was used to prepare metallic glass foam. In situ X-ray microtomography during load was performed at beam line ID15A of the ESRF. A cycle involving compressive loading towards a non-catastrophic collapse event followed by unloading was applied. Radiation exposure of foam raises a spontaneous temperature, which was effectively accommodated by a stress rise due to the inability of the constrained foam to thermally expand. Strains were estimated from the cross head displacement, and were corrected for the nonlinear machine compliance. Results show that the implementation of real-time X-ray microtomography confirms the yielding of metallic glass foam to evolve by percolation of local elastic membrane-buckling instabilities.