Effect of Rapid Solidification on Hardness and Grain Size of Copper Alloys

الملخص

Copper alloys are widely studied for their excellent properties, including electrical conductivity, corrosion resistance, and moderate mechanical strength. However, optimizing their mechanical properties, particularly hardness, remains a critical focus for various engineering applications. Grain size plays a crucial role in determining the hardness of copper alloys, and recent advancements in rapid solidification (RS) techniques have shown promise in refining grain structure to enhance hardness. This study investigates the effect of rapid cooling on the hardness and grain size of copper-zinc (brass), copper-tin (bronze), and copper-aluminum alloys. Using Vickers hardness tests and optical microscopy combined with electron microscopy analysis, the study examines the microstructural changes induced by RS, with particular attention to the relationship between grain size and hardness as described by the Hall-Petch relationship.

The results reveal a direct correlation between decreasing grain size and increasing hardness, which is consistent with the Hall-Petch relationship. Microscopic analysis confirms that grain refinement is the primary factor influencing the hardness of RS-processed copper alloys. Vickers hardness testing shows an increase in hardness from approximately 80 Hv for coarse-grained samples to 150 Hv for fine-grained samples. The study underscores the potential applications of rapid solidification in developing high-performance copper alloys for structural, electrical, and wear-resistant applications, where enhanced hardness is crucial.

This research contributes to the optimization of processing techniques for tailoring the mechanical properties of copper alloys for specific engineering applications.