The invention belongs to the technical field of surface treatment on
metal materials, and discloses normal-temperature alkaline
chromium-free
passivation solution and a
passivation method for aluminum
alloy. PH (potential of
hydrogen) of
chromium-free
passivation solution is regulated by the aid of acid-alkali regulators until the
chromium-free passivation solution is alkaline; the chromium-free passivation solution comprises
molybdate, complexing agents, oxidizing agents, film-forming accelerators, surfactants and water. The passivation method includes carrying out alkali washing on the aluminum
alloy and removing oil and
dirt from the aluminum
alloy; cleaning the aluminum alloy, then carrying out
acid washing on the aluminum alloy and activating the aluminum alloy; cleaning the aluminum alloy, carrying out normal-temperature passivation treatment on the aluminum alloy, washing the aluminum alloy by the aid of water,
drying the aluminum alloy by means of blowing or
drying the aluminum alloy by the aid of ovens to obtain aluminum alloy passivation films. The normal-temperature alkaline chromium-free passivation solution and the passivation method have the advantages that the passivation films can grow fast and are excellent in discoloration resistance and
corrosion resistance; various components of the normal-temperature alkaline chromium-free passivation solution are stable in chemical properties, accordingly, the normal-temperature alkaline chromium-free passivation solution is convenient to store and transport, low in cost and high in efficiency, processes are easy and convenient to implement, the aluminum alloy can be treated at the normal temperature, energy can be saved, and industrialization is easy to implement.