INFLUENCE OF TITANIUM ADDITIONS ON THE ELECTROCHEMICAL BEHAVIOUR OF NiCr/Ti LASER CLADDED COATINGS

Abstract

In this research, the electrochemical evaluation of NiCr/Ti laser cladded coatings in simulated polymer electrolyte membrane fuel cells (PEMFCs) environment was investigated. The Laser Cladding technique was used to develop protective coatings on mild steel substrate using NiCr-based powders mixed with 12.5, 15, 17.5 and 20 wt.% Ti additions. The samples were tested at room temperature in Na2SO4 0.1M + 0.1 ppm F-. The potentiodynamic polarization curves are presented before and after the samples were subjected to accelerated stress tests, for 6 hours each, at +0.736 V (cathodic environment) and at-0.493 V (anodic environment). Afterwards, scanning electron microscopy (SEM) was used to investigate the effect of Ti addition in terms of morphology. Energy-dispersive X-ray spectroscopy (EDS) was performed for chemical evaluation of the surface after corrosion tests.