Ni-Based Coatings on Molybdenum: Influence of Current Density and Basalt on Mechanical Properties and Forensic Relevance

Ni and Ni/basalt (Ni/Bst) coatings prepared by the electrodeposition on Mo substrate were analyzed with the aim of their potential application in forensics. The coatings of Ni and Ni/Bst are produced galvanostatically from the sulfamate electrolyte at different current densities and characterized by scanning electron microscope (morphology), X-ray diffraction (structure) and Vickers microindentation (microhardness). The wettability of Ni and Ni/Bst coatings was also investigated. While morphology and microhardness of the coatings strongly depended on the current density of electrodeposition and the presence of basalt particles in the electrolyte, the effect of basalt addition on structure of the coatings was not observed. The microhardness of Ni coatings was in the (1.6951–5.7246) GPa range, while the addition of basalt particles increased the range to (5.8206–10.7981) GPa. Both Ni and Ni/Bst coatings were hydrophilic, whereas comparison of the coatings obtained at the same current density showed that incorporation of the basalt particles in the coating decreases the degree of hydrophilicity, as observed by the increase in the water contact angle (WCA). The largest WCA, i.e., the smallest hydrophilicity, showed Ni/Bst coating produced at 30 mA cm−2 (WCA ≈ 75.5°), and was about 46.7% larger than that of Mo substrate (WCA ≈ 51.5°). This coating also showed the best development of latent fingerprints with clearly visible ridge details, indicating that there is strong correlation between fingerprint development and the wettability of the coatings.