Tuning Non-Isothermal Crystallization Kinetics between Fe₂₀Co₂₀Ni₂₀Cr₂₀(P_0.45B_0.2C_0.35)₂₀ High-Entropy Metallic Glass and the Predecessor Fe₇₅Cr₅P₉B₄C₇ Metallic Glass

Abstract

In the present work, comparisons of non-isothermal crystallization kinetics between Fe20Co20Ni20Cr20(P0.45B0.2C0.35)20 high-entropy metallic glass (HEMG) and the predecessor Fe75Cr5P9B4C7 metallic glass (MG) were performed with X-ray diffraction and differential scanning calorimetry approaches. The HEMG possesses a harsher crystallization process compared with the predecessor MG, deriving from a higher triggering energy for all the characteristic transitions and local activation energy along with a smaller local Avrami exponent and a growth with pre-existing nuclei. Meanwhile, the glass transition is the easiest process, but the nucleation of the second crystallization case is the hardest transition for the HEMG. However, the predecessor MG possesses distinctly different crystallization features of a moderate difficulty for the glass transition, the harshest process for the growth transition of the second crystallization case, and a crystallization of growth with a diverse nucleation rate. These results conclusively prove that the non-isothermal crystallization kinetics can be significantly changed after the present high-entropy alloying with the substitution of similar solvent elements Co, Ni, and Cr with Fe in Fe75Cr5P9B4C7 MG. Moreover, the two alloys possess a strong glassy formation melt with high thermal stability and diverse crystallized products after non-isothermal crystallization.

Keywords

• high entropy
• metallic glass
• similar solvent element substitution
• non-isothermal crystallization
• Avrami exponent
• activation energy