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.

中文翻译：

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Mg 61 Cu 28 Cd 11合金的微观非均质性和凝固条件

摘要

报告了有关液态Mg ₆₁ Cu ₂₈ Cd ₁₁合金从340加热到780°C以及随后冷却的运动粘度的原始实验数据。根据有关金属熔体的微观异质性的知识来讨论测量结果。粘度测定研究的结果用于确定温度T *，在该温度下液态Mg ₆₁ Cu ₂₈ Cd ₁₁合金的微观异质性被破坏（T* = 750°C）。发现了运动粘度随温度变化的异常行为：随着温度升高，粘度发生单调增加。使用摩尔粘度的概念根据物理化学的基础描述了熔体的准气态行为。研究了以1°C / s的速度固化的样品的微观结构。拍摄扫描电子显微镜图像并进行能量色散光谱分析；的纳米硬度ħ（GPA）和杨氏模量Ë中的Mg的量（GPa）₂ CuCd和Mg ₂ Cu相被测量。金相研究结果表明形成了Mg ₆₁ Cu ₂₈的未改性树枝状结构。Cd ₁₁锭。将液态Mg ₆₁ Cu ₂₈ Cd ₁₁合金加热到780°C不会完全破坏微异质性，这种方法不适用于制备块状非晶态合金。