Dynamic heat flux experiments in Cu67.64Zn 16.71Al15.65: Separating the time scales of fast and ultra-slow kinetic processes in martensitic transformations

Crackling noise and avalanches during the martensite phase transformation of Cu67.64Zn16.71Al15.65 were investigated. Heat flux measurements with extremely slow heating rates of 0.005 Kh -1 allowed sufficient separation between the continuous background and the avalanche jerks. The jerk enthalpy is below 3 of the total transformation enthalpy. The crackling noise follows power law behavior with an energy exponent near ε=1.8. The jerks are almost uncorrelated with approximately a Poisson distribution of the waiting times between jerks. Quantitative analysis showed a scaling behavior with p(wt) ∿ wt (γ-1)exp(-wt/Ï„)n with γ=0.7 and n ≈ 1. © 2011 American Institute of Physics.The calorimetric experiments have been supported in Seville by Project FIS2006-04045. J. Manchado wishes to thank to Fundacio´n Ca´mara for a research grant. We want to thank also to Dr. A. Planes for supplying the sample.Peer Reviewe