Antimicrobial property, corrosion resistance and tarnish resistance of cold-sprayed additive manufactured copper-nickel alloy

The management of infectious diseases has posed a significant challenge in recent years, drawing the attention of scientific communities. Copper is renowned for its robust antimicrobial properties; however, it is susceptible to tarnishing. In contrast, copper-nickel alloy demonstrates not only commendable mechanical strength and corrosion resistance but also exceptional antimicrobial efficacy. A suitable copper-nickel alloy was synthesised using cold spray additive manufacturing, blending copper and nickel powders. The resultant as-printed coupons underwent heat treatment at varying temperatures to ensure alloy formation, porosity reduction, and property enhancement. Both corrosion properties and hardness were investigated across different selected heat treatment conditions. The specimens exhibiting the highest corrosion resistance and hardness were selected for antibacterial and tarnish resistance testing. Stainless Steel 316 was employed in the antibacterial evaluation as a negative control for comparison. Notably, a fair well distribution of copper and nickel was observed within the as-printed product. The optimal heat treatment condition for the copper-nickel alloy was determined to be 1030 °C followed by air cooling, as it exhibited superior material properties compared to alternative heat treatment conditions. An assessment of antimicrobial performance underscored the alloy’s effectiveness in rapidly eradicating bacteria. Additionally, the highest strength samples underwent a tarnish resistance study, revealing elevated tarnish resistance. The nature of material performance in response to the heat-treatment process and antibacterial performance are discussed.