Abstract
Low-melting eutectic alloys represent promising candidates for production of phase change materials (PCMs). PCMs are widely used in the field of thermal energy storage (TES). The most important advantages of the low-melting metallic materials as PCMs are their high volumetric latent heat and high thermal conductivity. However, essential thermophysical properties such as melting point, latent heat of fusion, specific heat capacity, thermal conductivity, and surface tension for many low-melting eutectic alloys are still unknown.
In this study, melting temperature, latent heat of melting and thermal conductivity of the Bi-Sn-Zn eutectic alloy were experimentally investigated. Melting temperature and latent heat of melting were determined by using differential scanning calorimetry (DSC) and compared with the results of thermodynamic calculation according to CALPHAD (calculation of phase diagram) method. Thermal diffusivity of the investigated eutectic alloy at 25 °C was measured by using the xenon-flash method. Based on the experimentally determined thermal diffusivity and the specific heat capacity obtained by thermodynamic calculation, the thermal conductivity of the investigated eutectic alloy was determined to be 22.88 ± 1.83 W m^–1 K^–1. In addition, the microstructure of the investigated eutectic alloy was examined using scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS).

Key words
Bi-Sn-Zn system, eutectic alloy, latent heat of melting, thermal conductivity

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