Crystallization Kinetics Analysis of the Binary Amorphous Mg72Zn28 Alloy

Abstract

The aim of the study was to analyze the crystallization kinetics of the Mg72Zn28 metallic glass alloy. The crystallization kinetics of Mg72Zn28 metallic glass were investigated by differential scanning calorimetry and X-ray diffraction. The phases formed during the crystallization process were identified as α-Mg and complex Mg12Zn13 phases. Activation energies for the glass transition temperature, crystallization onset, and peak were calculated based on the Kissinger model. The activation energy calculated from the Kissinger model was Eg = 176.91, Ex = 124.26, Ep1 = 117.49, and Ep2 = 114.48 kJ mol−1, respectively.

Non-Isothermal Analysis of the Crystallization Kinetics of Amorphous Mg72Zn27Pt1 and Mg72Zn27Ag1 Alloys

“…The reflections corresponding to the α-Mg phase (about 2θ = 34) and the Mg12Zn13 (in two places about 2θ = 37 and 2θ = 39) were recognized for both the Mg72Zn27Pt1 (Figure 9a) and Mg72Zn27Ag1 (Figure 9b) alloys. The crystalline phases formed first are the same as in the case of an Mg72Zn28 alloy [20]. The reflections from α-Mg have a much higher intensity compared to Mg12Zn13, which means that there is more of this first phase in the system.…”

“…The reflections corresponding to the α-Mg phase (about 2θ = 34) and the Mg 12 Zn 13 (in two places about 2θ = 37 and 2θ = 39) were recognized for both the Mg 72 Zn 27 Pt 1 (Figure 9a) and Mg 72 Zn 27 Ag 1 (Figure 9b) alloys. The crystalline phases formed first are the same as in the case of an Mg 72 Zn 28 alloy [20].…”

“…This is especially visible for the alloy with Pt, while the alloy with Ag shows slightly more Mg12Zn13 phase compared to Mg72Zn27Pt1. The lowest intensity for the Mg12Zn13 phase of these three alloys occurred for the two-component alloy [20].…”

“…Moreover, the addition of alloying elements, i.e., Pt or Ag, to the base alloy Mg 72 Zn 28 [20] causes their shift towards higher temperatures. Platinum has the greatest impact (it raises T x by approximately 50 K), because it has a higher melting point (1770 • C/2043 K) [21].…”

Modelling Crystalline α-Mg Phase Growth in an Amorphous Alloy Mg72Zn28

“…Appropriate isothermal annealing temperature values were necessary. Based on the research carried out in the work of Opitek et al [30] for the amorphous Mg 72 Zn 28 alloy, the following values were selected: 350 K, 352 K, 353 K, 353.5 K, and 354 K. The total crystallisation time for each of these temperature values was, respectively, 6001 s, 4067 s, 2916 s, 2644 s, and 2447 s. The simulation results are shown in Figure 6. Each graph shows the increase in grain size in the amorphous phase over time for a given isothermal annealing temperature.…”