Abstract
Original experimental data on the kinematic viscosity of the liquid Mg61Cu28Cd11 alloy during its heating from 340 to 780°C and subsequent cooling are reported. The measurement results are discussed in terms of the knowledge about the microheterogeneity of metallic melts. The results of the viscosimetric study are used to determine temperature T* at which the microheterogeneity of the liquid Mg61Cu28Cd11 alloy is destroyed (T* = 750°C). The anomalous behavior of the temperature dependences of the kinematic viscosity is found: as the temperature increases, a monotonic increase in the viscosity takes place. The quasi-gaseous behavior of the melt is described in terms of the foundations of physical chemistry using the concept of molar viscosity. The microstructure of samples solidified at a rate of 1°C/s is studied. Scanning electron microscopy images are taken and energy-dispersive spectroscopy is performed; the nanohardness H (GPA) and Young’s modulus E (GPa) of the Mg2CuCd and Mg2Cu phases are measured. The results of metallographic study indicate the formation of an unmodified dendritic structure of an Mg61Cu28Cd11 ingot. Heating of the liquid Mg61Cu28Cd11 alloy to 780°C does not result in complete destruction of the microheterogeneity, and this method is unsuitable for the preparation of bulk amorphous alloys.
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Translated by N. Kolchugina
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Chikova, O.A., Barashev, A.R., Tkachuk, G.A. et al. Microheterogeneity and Solidification Conditions of an Mg61Cu28Cd11 Alloy. Russ. Metall. 2020, 731–737 (2020). https://doi.org/10.1134/S0036029520070046
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DOI: https://doi.org/10.1134/S0036029520070046