Method for Preparing a Coating Resistant to Contact Corrosion on the Surface of Titanium Alloy

A titanium alloy part with a corrosion resistant surface coating for contact corrosion, comprising:

• a coating having a thickness of 200-300 μm, said coating contains a diffusion layer formed through diffusion of atoms at the interface on a substrate, the diffusion layer leads to a metallurgical combination between the coating and the substrate, a thickness of said diffusion layer is 10-30 μm, and said diffusion layer is formed through the following steps:
• a first step of carrying out degreasing and derusting to a titanium alloy part;
• a second step of carrying out etching treatment on the titanium alloy part;
• a third step of carrying out surface activation treatment on the titanium alloy part;
• a fourth step of preheating the titanium alloy part in an atmosphere protection furnace;
• a fifth step of immersing the preheated titanium alloy part in plating solution in a way that the part is rotated in the submerging process;
• and a sixth step of carrying out diffusion treatment on the immersion-plated titanium alloy part in a vacuum furnace whereby atoms on the interface diffuse to form a diffusion layer on a substrate and thus form a plating diffusion composite layer on the surface of the titanium alloy part and thereby realizing metallurgical combination between the coating and the substrate.