Advanced Surface Engineering and Protective Coating

The surface and near-surface layers of structural metal alloys are the front line against corrosion, erosion, and wear attacks from their working environments. To enhance the surface layers without degrading the mechanical strength of the base material, various surface engineering technologies have been redeveloped in the past decade driven by ever-increasing requirements for additive manufacturing of metallic components. In general, the surface engineering techniques can be catalogued into two groups. One is surface treatment that either enhances the intrinsic surface materials via introducing plastic deformations or converts them into more thermodynamically stable materials upon direct energy flux. The other is surface coating by single or multiple layered extrinsic materials that have higher corrosion and wear resistances than those of the base material. Hybrid methods between the two groups have also been proposed in recent years for advanced surface engineering. Here, we briefly introduce a few techniques for advanced surface engineering and protective coating, highlighting their remaining challenges and promising potentials.