Synergistic Effects of High-Speed Directional Solidification on the Mechanical Properties of Zn–Al–Cu Eutectic Alloy

The Zn–5.0Al–0.5Cu (wt.%) eutectic alloy was produced using melting and casting furnaces operating under vacuum during the production stage. The prepared alloy was subjected to unidirectional solidification in a Bridgman-type directional solidification apparatus under a constant temperature gradient (G = 3.67 K/mm) and a wide range of growth rates (V = 8.45–2087.15 μm/s). The resulting microstructures were examined using a field emission scanning electron microscope (FESEM). Experimental results indicate that the acceleration in solidification kinetics directly modifies the microstructure, leading to a superior mechanical combination of mechanical properties in terms of both microhardness and tensile strength. This correlation provides a new perspective for optimizing Zn–Al–Cu alloy systems for high-performance engineering applications. The obtained data were comprehensively evaluated by comparing them with Zn-Al based alloys in the literature.