Synergistic Enhancement of Chromaticity and Corrosion Resistance in Gold-Like Cu-Zn Alloy Targets via Multi-Element Doping

Abstract

This study presents a systematic investigation into enhancing the chromaticity and corrosion resistance of copper-zinc-based gold-like target materials through a multi-element (Al, Mn, Zr) alloying strategy. Sixteen distinct alloy compositions were designed and fabricated via medium-frequency induction melting. Notably, Chromaticity analysis revealed that the optimized composition (Sample No. 9: Cu-65 wt.%, Al-3 wt.%, Mn-3 wt.%, Zr-0.6 wt.%, bal. Zn) yielded the closest color match to pure gold, achieving a minimum color difference (ΔE) of 11.25. Comprehensive electrochemical characterization in a 3.5 wt.% NaCl solution demonstrated that this optimal sample also exhibited excellent corrosion resistance, with a charge transfer resistance (Rct) of 5.99 Ω·cm² and a corrosion current density (Icorr) of 1.5073 × 10⁻⁶ A·cm⁻². Among the dopants, Mn was identified as the most influential element in suppressing corrosion. Microstructural analysis via scanning electron microscopy (SEM) elucidated the underlying mechanism: the enhanced performance was attributed to the refined α + β dual-phase structure and the uniform dispersion of Zr/Mn-containing nano-precipitates, which collectively hindered corrosive attack. This work provides a fundamental experimental basis and valuable insights for designing high-performance, gold-like alloy targets for advanced decorative coatings.