Strain intermittency in shape-memory alloys
Friday, October 23, 2015 - 3:30pm - 4:10pm
Giovanni Zanzotto (Università di Padova)
We study experimentally the intermittent progress of the mechanically induced martensitic transformation in a Cu-Al-Be single crystal through a full-field measurement technique: the grid method. We utilize an especially designed gravity-based device which applies a perfectly monotonic uniaxial load through very small force increments. The sample exhibits hysteretic superelastic behavior during the forward and reverse cubic-monoclinic transformation, produced by the evolution of the strain field of the phase microstructures. The in-plane linear strain components are measured on the sample surface during the loading cycle, and we characterize the strain intermittency in a number of ways, showing the emergence of power-law behavior for the strain avalanching over almost six decades of magnitude. Joint work with X. Balandraud, N. Barrera, P. Biscari, M Grédiac.