Tuning isothermal crystallization kinetics by minor similar solute element substitution in novel La‐(AlGa)‐C metallic glasses

Abstract

In the present text, the effects of minor similar solute element Ga substitution for Al on the isothermal crystallization kinetics of novel light RE‐based La‐(AlGa)‐C metallic glasses (MGs) were systematically investigated between La60Al26Ga4C10 MG and the precursor La60Al30C10 MG by using phase analysis, Johnson–Mehl–Avrami and Arrhenius using x‐ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The incubation period, the accomplishment time of the whole process, and the diversity of both the precipitated phases and the varying trend of the local Avrami exponent are elevated by minor similar solute element Ga substitution for Al, respectively. Additionally, the Avrami exponent of different isothermal crystallization temperature changes from g n > 2.5 to a combination of values 1.5 < n < 2.5 and a value n > 2.5 given by minor similar solute element Ga substitution for Al, corresponding to the crystallization characteristics changing from crystallization with promoting nucleation rate to a combination of crystallization with a reducing nucleation rate and crystallization with promoting nucleation rate. Moreover, the isothermal crystallization process becomes more difficult after minor similar solute element Ga substitution for Al, due to the reduced Avrami exponent and the intensified local activation energy.