A method for determining the crystallization temperature in studying internal friction behaviors of bulk metallic glasses

Abstract As well known, internal friction ( Q − 1 ) is one of useful resorts for investigating the mechanical relaxation behaviors of bulk metallic glasses (BMGs). However, so far it has been controversial on ascertaining the authentic position of crystallization temperature ( T x ) when the peak arises on Q − 1 - T heating curve of BMGs. Based on the isochronous measurement results of internal friction and resistivity ( ρ ) on a series of BMGs, a novel method for determining T x of BMGs was proposed. By differentiating the curve of Q − 1 - T with respect to temperature to obtain d Q − 1 / d T-T curve, the inflexion temperature at the left side of the Q − 1 -T peak can easily be determined. It is interesting to find that, for all the investigated BMGs in this paper, this inflexion temperature (the peak position of the d Q − 1 / d T-T curve) is in correspondence with the T x obtained from ρ - T curve ( ρ is very sensitive to crystallization), with the temperature error of ± 1.5 K. These results suggest that in studying the internal friction behaviors of BMGs, the crystallization temperature can be determined with the inflexion temperature of the Q − 1 -T curve, and the position of T x for BMGs locates at the left side of the Q − 1 -T peak, rather than at the Q − 1 -T peak temperature or others as pointed in some references.