The present study highlights the effect of the cooling rate on the microstructure formation of Si–Mo ductile iron. In this study, experiments were carried out for castings with different wall thicknesses (i.e., 3, 5, 13, and 25 mm) to achieve various cooling rates. The simulation of the cooling and solidification was performed through MAGMASOFT to correlate the cooling conditions with the microstructure. The phase diagram of the investigated alloy was calculated using Thermo-Calc, whereas the quantitative metallography analyses using scanning electron microscopy and optical microscopy were performed to describe the graphite nodules and metallic matrix morphologies. The present study provides insights into the effect of the cooling rate on the graphite nodule count, nodularity, and volumetric fractions of graphite and ferrite as well as the average ferritic grain size of thin-walled and reference Si–Mo ductile iron castings. The study shows that the cooling rates of castings vary within a wide range (27 °C–1.5 °C/s) when considering wall thicknesses of 3 to 25 mm. The results also suggest that the occurrence of pearlite and carbides are related to segregations during solidification rather than to cooling rates at the eutectoid temperature. Finally, the present study shows that the longitudinal ultrasonic wave velocity is in linear dependence with the number of graphite nodules of EN-GJS-SiMo45-6 ductile iron.

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 E_g = 176.91, E_x = 124.26, E_p1 = 117.49, and E_p2 = 114.48 kJ mol⁻¹, respectively.