Electrochemical performance and microstructural evolution of laser deposited Al‐Sn coating in acidic environment

Abstract

AbstractOutstanding performance of materials is one of the requirements of modifying the existing materials in order to meet a global demand necessary in technology innovation. Direct laser metal deposition technique due to excellent properties has replaced conventional techniques in modifying the surface of materials. The interplay between melting, fusion and optimised laser parameters are very important factors to be considered when using laser metal deposition technique. ASTM A29 steel property was enhanced through this technique by Al‐Sn reinforcements. A 3‐kW continuous wave ytterbium laser system was employed by this process. This research investigated the microstructure and corrosion properties of fabricated laser metal deposited ASTM A29 steel. The resulting microstructure and content of the inconsequential elements in the coatings fabricated were studied to obtain the results achieved. Observation of the microstructure showed typical phase of acicular α′‐martensite attributed to rapid cooling of the molten pool. The electrochemical behaviour was investigated in 1 M HCl solution at 27 °C via potentiodynamic polarization technique. The fabricated coatings had corrosion rate of 0.03435 mm/yr, current density of 3.95 ⋅ 10−6 A/cm2, and polarization resistance of 7093.4 Ω ⋅ cm2. While the control had corrosion rate of 16.308 mm/yr and polarization resistance of 8.0631 Ω ⋅ cm2.