Abstract:Powder sherardizing has the advantages of good corrosion resistance, high bonding strength with the matrix, and low melting point of the material. However, improving the quality of the powder zinc layer and optimizing the performance of powder zinc layer are still the aspects that need to be studied. In this paper, different doping amounts of rare earth element La (mass fractions of 0%, 1.3%, 2.7%, 4.0%, 5.3%) were added to the sherardizing agent for surface sherardizing treatment of metal structural parts. Use SEM to observe surface morphology, XRD to determine phase and proportion, confocal laser scanning microscope (CLSM) to generate ultra-high resolution 3D surface morphology images to evaluate surface roughness characteristics, nanoindentation (Nano Indenter G200) study the hardness of the powder zinc layer to evaluate its mechanical properties.The results show that adding 4.0% rare earth element La to the sherardizing agent can better improve the microstructure of the infiltrated layer, increase the columnar and compact δ phase in the permeable layer to make the structure of the layer fine and compact, and reduce the occurrence of defects such as pits and cracks, thereby improving the uniformity of the layer. The hardness of the layer in the thickness direction is improved, and the hardness distribution is more uniform.By measuring the open circuit potential (OCP), polarization curve (Tafel) and electrochemical impedance spectroscopy (EIS) of the material, it is shown that the corrosion resistance of the layer formed by adding 4.0% La element is better.