Titanium surface magnesium hydrogen phosphate chemical conversion coating and preparation method and application thereof

The invention discloses a titanium surface magnesium hydrogen phosphate chemical conversion coating and a preparation method and application thereof, and the preparation method comprises the following steps: preparing a chemical conversion liquid which contains magnesium ions, sodium ions, phosphate ions, nitrate ions and an accelerant; by adding sodium hydroxide, the initial pH of the solution can be increased, the pH of the curing liquid can be conveniently adjusted subsequently, and solution precipitation caused by too high pH in the adjusting process is prevented. The chemical conversion liquid is subjected to iron powder curing treatment, and cured liquid is obtained; and coupling the cleaned and surface-activated titanium substrate with a pure iron clamp, and then soaking the coupled titanium substrate in a curing solution for chemical conversion treatment to obtain the chemical conversion coating. And by regulating and controlling the temperature of the conversion liquid, controllable preparation of di