INFLUENCE OF CERIUM ON THE TEMPERATURE DEPENDENCE OF THE HEAT CAPACITY AND CHANGES IN THE THERMODYNAMIC FUNCTIONS OF ALLOY AlСu4.5Mg1

Statement of the problem (relevance of the work): The use of aluminum and its alloys as structural materials is due to their resistance to corrosion. Aluminum alloys have high resistance to corrosion in atmospheric and marine conditions, in alkaline and acid solutions, low density, good machinability. In terms of corrosion resistance, these alloys are significantly superior to cast alloys of other aluminum-based systems. The high corrosion resistance of aluminum alloys in various media is determined by the formation of a hydrated film that delays the corrosion process. The high strength of the alloys of this system is associated with an increase in the distortion of the crystal lattice with an increase in the content of copper and magnesium in the solid solution. To improve the corrosion and mechanical properties, additives of various metals are introduced into aluminum alloys. One of the most important characteristics of aluminum alloys is heat capacity. Knowledge of the heat capacity and its temperature dependence plays an important role in the study of alloys. The purpose of the work: to study the temperature dependence of the thermophysical properties and thermodynamic functions of the AlCu4.5Mg1 aluminum alloy with cerium. Methods used: Many methods are known for measuring the heat capacity of a solid. In this work, a method is used to compare the cooling curves of the reference and test samples in the “cooling” mode using an aluminum standard (Al A5N) in the range of 300 – 800 K. 5Mg1. Result: mathematical models have been established that describe the temperature dependence of the heat capacity of the alloy on the cerium content and the change in their thermodynamic functions in the specified temperature range. As a result of the studies carried out, it was shown that with increasing temperature, the heat capacity, enthalpy and entropy of alloys increase, and the value of the Gibbs energy decreases. Practical significance: the obtained characteristics of thermophysical properties and thermodynamic functions of aluminum alloy AlCu4.5Mg1 with cerium fill up the pages of the relevant reference books on the thermophysics of materials and can be used in the design of parts and machines from these alloys.

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