Composite alloy material, preparation method thereof and metal structural part

The invention discloses a composite alloy material, a preparation method of the composite alloy material and a metal structural component, and the method comprises the steps that a composite alloy matrix is subjected to micro-arc oxidation, so that an oxidation layer is formed on at least part of the surface of the composite alloy matrix, a first middleware is obtained, and electrolyte for micro-arc oxidation comprises silicate, fluoride salt, lithium hydroxide and aluminate; polishing the surface of the first middleware to obtain a second middleware; forming an appearance film layer on at least part of the surface of the second middleware; wherein the composite alloy matrix comprises at least one of a magnesium-aluminum composite matrix and a titanium-aluminum composite matrix. Micro-arc oxidation treatment is carried out on the surface of a composite alloy matrix by adopting the electrolyte formula, and meanwhile, an oxidation layer with high hardness and high compactness is formed, so that the binding forc