Electroless nickel-phosphorus amorphous alloy coating as effective barrier for hydrogen permeation and corrosion protection

This study focuses on the electroless nickel-phosphorus amorphous coating and its performance as an effective barrier against hydrogen permeation and corrosion. The coating was deposited on 16Mn substrate using the electroless plating technique. The microstructure and chemical composition of the coatings were systematically characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Hydrogen permeation experiments were performed using the Devanathan-Stachurski (D-S) dual-electrolytic cell system to quantitatively assess the coating's hydrogen barrier efficiency and its effectiveness in suppressing hydrogen diffusion across the substrate. Moreover, Potentiodynamic polarization curves (PPC) and electrochemical impedance spectroscopy (EIS) were performed using a electrochemical workstation in 3.5 wt% NaCl solution. The results indicated that a uniform and dense nickel-phosphorus alloy coating with an amorphous structure was successfully prepared on the 16Mn substrate via electroless chemical deposition. Hydrogen permeation tests revealed that increasing the thickness of the Ni–P amorphous coatings significantly prolonged hydrogen permeation time and effectively reduced the hydrogen diffusion coefficient, demonstrating exceptional hydrogen barrier performance. Furthermore, the electroless nickel-phosphorus amorphous coating exhibited enhanced corrosion resistance compared to the uncoated substrate. The coating's amorphous structure and the presence of phosphorus were found to play crucial roles in its barrier and corrosion protection mechanisms. Overall, the electroless nickel-phosphorus amorphous coating shows great potential as a reliable solution for applications where hydrogen permeation and corrosion protection are of utmost importance.