Surface treatment method of aluminum alloy and treatment liquid

Abstract

The invention relates to a surface treatment method of aluminum alloy, which comprises the following steps of: pre-treating: removing oil stains on the aluminum alloy surface by adopting an alkali degreasing solution; alkali washing: purifying the aluminum alloy surface at 50-60 DEG C by adopting alkali wash to remove a natural oxide film on the aluminum alloy surface; acid pickling: treating the aluminum alloy surface at room temperature for 1-5 minutes by adopting a pickling solution to further remove residual spots left on the aluminum alloy surface after alkali washing; and chemically plating Ni-P: forming a Ni-P plating layer on the aluminum alloy surface by adopting a pre-prepared chemical plating Ni solution with pH value of 5-6.5 at 85-90 DEG C for 90-240 minutes. By adopting a chemical plating Ni-P layer process to form a uniform favorable plating layer with good acid resistance, alkali resistance and salt resistance outside an aluminum alloy shell, the invention avoids the phenomena of uneven thickness of a protective layer and spraying missing on a complex structure part, and remarkably improves the anticorrosion performance of the aluminum alloy.

Description

technical field

[0001] The invention relates to the field of surface treatment, in particular to a surface treatment method and a treatment liquid for aluminum alloys. Background technique

[0002] For the aluminum alloy-based components used in daily life, the surface anti-corrosion treatment usually involves spraying plastic powder or applying anti-corrosion coatings on the outer surface of the components. The main disadvantage of this treatment method is that the thickness of the protective layer obtained by spraying plastic powder or applying anti-corrosion coating is not uniform, and it is difficult to spray on the parts with complex structures such as bends and corners of components, so it is often damaged in harsh environments. Cracks, cracks, or even large pieces fall off, causing the aluminum alloy substrate to corrode; especially when the aluminum alloy substrate is used for the casing of electrical devices, it is not allowed to use paint to protect the explosion-p...