Calorimetry of crystallization processes of amorphous alloys based on the quasi-binary system TiN–TiCu

The influence of the degree of polynomial smoothing of experimental data from differential scanning calorimetry of amorphous metal alloys Ti$_{50}$Ni$_{25}$Cu$_{25}$, Ti$_{30.2}$Ni$_{49.8}$Hf$_{20}$, Ti$_{40.5}$Ni$_{49.8}$Zr$_{9.7}$, Ti$_{50.2}$Ni$_{24.8}$Cu$_{24.4}$Al$_{0.6}$, Ti$_{50.2}$Ni$_{24.8}$Cu$_{24.4}$Fe$_{0.6}$ on the determined values of exothermic effects during crystallization. It is shown that the values of the thermodynamic parameters obtained from these data are practically independent of the degree of polynomial smoothing. However, this procedure has an impact, and it is very significantly, the kinetic characteristics of the crystallization process of amorphous metal-metal alloys during their heating. The enthalpy of the crystallization process of such alloys turned out to be an order of magnitude lower than in the case of conventional crystallization of alloys of the same composition. The beginning of crystallization of these alloys can be formally described by functions with exacerbation, which characterizes the initial process. Crystallization is both spontaneous and high-speed. The introduction of refractory components such as Hf and Zr into the composition of alloys somewhat suppresses this trend. It is significant that during the crystallization of amorphous alloys based on the quasi-binary TiNi–TiCu system, the temperatures of the maximum rate of occurrence of crystallization centers and the maximum rate of their growth practically coincide with each other, which is not observed during conventional crystallization from melts.