Consecutive nucleation events during divetrification of Zr 52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass

DSC, XRD, and in-situ synchrotron diffraction experiments were carried out to investigate the devitrification behavior of Zr_52.5Cu _17.9Ni_14.6Al₁₀Ti₅ bulk metallic glass. Through careful measurements of isochronal and isothermal DSC traces, we identified two consecutive exothermal peaks. XRD patterns collected at various stages of isothermal annealing and in-situ synchrotron data collected during isochronal heating indicate that the exothermal peaks correspond to two nucleation events, with different local atomic structures. Multi-parameter refinement of both isochronal and isothermal DSC data show that the devitrification behavior of this alloy is adequately described by JMA theory with a two-step consecutive reaction model, so long as the heating rate is <10 K/min. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.