Crystallization kinetics of Cu–Zr–Al bulk metallic glass with Nd addition

Abstract The crystallization kinetics of (Cu 48 Zr 48 Al 4 ) 100− x Nd x ( x = 0, 2 at.%) bulk metallic glasses in nonisothermal and isothermal conditions were studied by differential scanning calorimetry and X‐ray diffraction (XRD). XRD analysis shows that the crystallization product Cu 10 Zr 7 changes to Cu 10 Zr 7 and Cu 2 Nd with Nd presence in nonisothermal and isothermal conditions. Crystallization activation energy was calculated in nonisothermal conditions using Kissinger and Ozawa methods and in isothermal conditions using Arrhenius model. The results show that the activation energy harbored by (Cu 48 Zr 48 Al 4 ) 98 Nd 2 expresses larger value compared with Cu 48 Zr 48 Al 4 , which indicate that the energy barrier for crystallization has enhanced along the Nd addition. The Johnson–Mehl–Avrami model was employed for analyzing the crystallization kinetics in isothermal condition. The Avrami exponent n for Cu 48 Zr 48 Al 4 is more than 2.5, demonstrating that the crystallization is mainly governed by diffusion‐controlled three‐dimensional growth with increasing nucleation rate. Comparably, the Avrami exponent n for (Cu 48 Zr 48 Al 4 ) 98 Nd 2 is 1.5 < n < 2.5, suggesting that the crystallization is mainly determined by diffusion‐controlled three‐dimensional growth with decreasing nucleation rate. The evident enhancement in crystallization activation energy based on Nd addition is rationally made up of an influential factor commonly harbored on the enhanced glass forming ability for the rare‐earth comprising Cu–Zr–Al metallic glasses.