Development of electroless Ni–P modified aluminum substrates in a simulated fuel cell environment

• Pure Al and some of its alloys were coated with electroless Ni–P.
• Coating AA1050 with Ni–P reduces its corrosion current density by 44.69 times.
• Coated AA6061 is the least stable under simulated cathodic condition in PEMFCs.
• The corrosion process is mainly controlled by charge transfer as shown by EIS study.

The corrosion resistance of electroless Ni–P coating on pure Al, Al 6061, Al 3004 and Al 1050 is examined in an environment simulated to PEM fuel cell. Potentiodynamic polarization techniques, Interfacial contact resistance, surface morphology, chemical composition of coated substrates and EIS measurements have been investigated. Modified Al 1050 showed reduction in its corrosion current density by 44.69 times. It also showed the best stability of all modified Al substrates. The formed Ni–P layer on Al 1050 is thicker by about 3 times, relative to that on Al 6061 and has higher Ea value of 135.68 kJ mol−1 supporting its lower corrosion rate.