The invention provides a preparation method of an environment-friendly self-healing type
titanium /
zirconium /
molybdenum conversion film on the surface of aluminum
alloy. The preparation method comprises the following steps that surface pretreatment is conducted on each aluminum
alloy sample; a conversion solution is compounded, wherein the conversion solution comprises 0.5-5 g / L of fluotitanate, 0.5-3 g / L of fluozirconate, 1-6 g / L of
molybdate, 0.2-3 g / L of a chelating agent, 0.3-3 g / L of a film formation additive and 0.2-0.5 g / L of a pH value adjustment agent, water is added after all components are mixed, stirring is conducted for 30-50 minutes, then, sealing is conducted, and aging is conducted for one day; the conversion film is prepared, wherein each aluminum
alloy sample is soaked inthe conversion solution, the continuous and uniform faint-yellow
titanium /
zirconium /
molybdenum conversion film can be formed on the surface of the aluminum alloy, the aluminum alloy samples are takenout and thoroughly cleaned through
distilled water, and
drying is conducted, so that preparation of the conversion film is completed. By means of the preparation method, the film formation temperatureis low, the film formation time is short, the conversion solution is stable, no
chromium is adopted, and environmental friendliness is achieved; the surface of the aluminum alloy is good in corrosionresistance and capable of achieving self-healing; and the preparation method is applicable to various types of aluminum alloy.