Characterization of ZnAl cast alloys with Li addition

• High temperature soldering materials ZnAl with Li were designed and characterized.
• Precipitates from Al–Li system, was observed and confirmed using TEM and XRD.
• Addition Li to eutectic ZnAl caused increased the mechanical properties.
• Li content caused increased electrical resistivity, microhardness and CTE.

The addition of Li to eutectic ZnAl alloy caused improved mechanical and thermal properties, with potential application in new design materials used in the automotive and aerospace industries. The alloys with 0.05, 0.1, 0.2, 0.5 and 1.0 Li (wt.%) content were studied using calorimetry, to determine the melting temperatures. Thermal linear expansion and electrical resistivity measurements were performed at temperatures of − 50 °C to 300 °C and 30 °C to 300 °C. The microstructure of the specimens was analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Chemical microanalysis was performed using energy-dispersive X-ray spectroscopy (EDS) on SEM and TEM. The possibility of the occurrence of Al–Li, Li–Zn and Al–Li–Zn precipitates was studied by X-ray diffraction (XRDs) and selected area electron diffraction (SAED). The addition of Li to eutectic ZnAl alloy increased the electrical resistivity and the coefficient of thermal expansion; however, the melting point did not change. The mechanical properties, strain and microhardness increased with Li content in alloys.

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