Hardness Investigation of the Electroplated Ni–Co Alloy

Electroplated hard metal coatings are sought after for their anti-wear properties and cost-effective deposition process. However, traditional choices like hard chrome and tungsten present challenges in terms of fabrication and environmental concerns. To address this, we explored the electroplating process under a binary sulfamate system to produce a hard Ni-Co alloy coating on metal surfaces. Our findings revealed that the electroplating current density predominantly influenced the hardness of the Ni–Co alloy, with higher current densities resulting in lower Co concentrations. Surprisingly, the composition of the alloy remained consistent regardless of the current density and showed little sensitivity to the Co²⁺ concentration. The highest hardness value of 608.1 HV0.05, with a Co concentration of 34%, was achieved at a current density of 3 ASD. These results highlight the potential of electroplated Ni–Co alloy coatings as alternatives to traditional options, offering controlled hardness properties and stable compositions. Further research is needed to assess their mechanical properties and applicability in various industries.