Thermal diffusing permeation method of inorganic rare earth molten salt on surface of magnesium alloy

The invention provides a thermal diffusing permeation method of an inorganic rare earth molten salt on the surface of a magnesium alloy. The method is characterized in that the magnesium alloy of which surface is cleaned is placed in an anhydrous inorganic rare earth molten salt system AlCl3-NaCl-KCl-CeCl3, the molten salt system is heated and the temperature is maintained, and a cerium-containing magnesium-aluminum intermetallic compound diffusion-permeation layer with high corrosion resistance is formed on the surface of the magnesium alloy through diffusing permeation. The method has the following advantages: on one hand, the rare earth element Ce in the molten salt system has the function of promoting permeation, thus the permeation of Al atom into the surface of the magnesium alloy is promoted; on the other hand, the rare earth element Ce has the function of microalloying, thus the microstructure of the diffusion-permeation layer can be improved and the corrosion resistance can be further increased. The