Crystallization kinetics of Hf28Be18Ti17Zr17Cu7.5Ni12.5 high-entropy bulk metallic glass

Crystallization kinetics of Hf28Be18Ti17Zr17Cu7.5Ni12.5 high-entropy bulk metallic glass (HE-BMG) in the non-isothermal and isothermal conditions were investigated by differential scanning calorimetry (DSC). In non-isothermal crystallization condition, DSC traces exhibited three crystallization processes. The apparent activation energies of peak crystallization temperatures were calculated by Kissinger methods and found to be E-p1 > E-p2 > E-p3. The dependence of local activation energy on crystallized volume fraction was summarized by the Kissinger-Akahira-Sunose (KAS) method. The non-isothermal crystallization reaction was described mathematically using the Sestak-Berggren model. In the isothermal crystallization condition, with the increase of annealing temperature, the incubation time and crystallization time become shorter and the crystallization peak becomes higher. All Avrami indices were less than 2.5, indicating that crystallization of glassy alloy is dominated by a diffusion-controlled three-dimensional growth with a decreasing nucleation rate.

Automated summary

The crystallization kinetics of Hf28Be18Ti17Zr17Cu7.5Ni12.5 high-entropy bulk metallic glass (HE-BMG) were investigated using differential scanning calorimetry (DSC) under non-isothermal and isothermal conditions. Three crystallization processes were observed in non-isothermal conditions, with the activation energies of peak crystallization temperatures determined. The dependence of local activation energy on crystallized volume fraction was analyzed using the Kissinger-Akahira-Sunose (KAS) method. The mathematical description of non-isothermal crystallization reaction was achieved using the Sestak-Berggren model. Under isothermal conditions, the incubation time and crystallization time decreased while the crystallization peak increased with increasing annealing temperature. The Avrami indices were all less than 2.5, indicating diffusion-controlled three-dimensional growth with decreasing nucleation rate in the crystallization of the glassy alloy.