Effects of deposition current density, time and scanning velocity on scanning jet electrodeposition of Ni-Co alloy coating

Abstract

Jet electrodeposition has superior application prospects in the preparation of nanostructured alloy coatings, which is suitable for high current density deposition and has selective deposition characteristics. The purpose of this work is to clarify the combined effect of multiple factors on the properties of alloy coatings prepared by jet electrodeposition. The L16 made by Taguchi orthogonal array was used in the experiment. The work studied the influence of process parameters such as deposition time (t), current density (i) and scanning velocity (v) on the properties of NiCo alloy coatings prepared on 304 stainless steel, which was set as the substrates. Material deposition rate (MDR), coating microhardness and coating surface roughness (SRa) were selected as the test indicators to characterize the coating properties. Analysis of Variance (ANOVA) was done to analyze the experimental data. The results indicated that current density had the greatest effect on MDR, coating microhardness and coating surface roughness, followed by deposition time and scanning velocity. The optimal parameters combination was selected, listed as follows: deposition time 20 min, current density 70 A·dm−2 and the scanning velocity 10 mm·s−1. The coating microhardness was 532.40 HV, coating SRa was as low as 85 nm, adhesion between coating and substrate was as high as 26.12 N and self-corrosion current density was 5.718 × 10−3 μA·cm−2 under the optimal parameters combination, which showed good performance. This processing method can guide the preparation of NiCo alloy coatings by jet electrodeposition, while the good performance exhibited by the coating can provide a reference for the anti-corrosion and wear-resistant treatment of marine equipment and textile machinery.