Achieving Optimal Dendritic Morphology in Ultralight Copper Powder Production through Hydrochloric Acid Intervention

The production of ultralight copper powder (UCP) remains challenging due to the requisite ultralow apparent density coupled with a well-developed dendritic morphology, which greatly constrain the modulation and optimization of process parameters. In this study, we conducted a comprehensive investigation to gain deeper insights into the impact of these parameters on the performance of deposited UCPs. Our findings revealed the limitations of relying solely on conventional electrolytic parameters for tailored UCP production. To overcome this challenge, the introduction of hydrochloric acid into the electrolyte system was proposed. Upon which, remarkable improvements in UCP production were observed, including optimized dendritic morphology, enhanced current efficiency and reduced power consumption. By adjusting the amount of chloride addition, UCPs with tunable particle sizes and apparent densities were obtained. Under the benchmark factory process condition, the chloride-treated UCP exhibited an ultralow apparent density (0.47 g cm⁻³) and particle size (19.96 μm), considerably surpassing the corresponding figures for industrial copper powder (1.79 g cm⁻³ and 64.10 μm) and even the optimum values achieved by GGP Metalpowder AG for their UCP products (0.55 g cm⁻³ and < 63 μm), with 22.5% of the particles exhibiting simultaneously ultralight and ultrafine properties.