Hard anodic oxidation pre-treatment technology applicable to protection of groove and blind hole parts

Abstract

The invention belongs to the technical field of surface treatment and in particular relates to a hard anodic oxidation pre-treatment technology applicable to protection of groove and blind hole parts.A flow of the hard anodic oxidation pre-treatment technology comprises the following steps: inspecting and accepting a workpiece; removing gasoline; insulating protection glue of the groove and blindhole parts; hanging; chemically removing oil; washing with hot water; washing with cold water; carrying out acid etching; washing with the cold water; washing with the cold water; carrying out hard oxidation; washing with the cold water; washing with the cold water; sealing; washing with the cold water; washing with the cold water; drying; detaching; drying; removing insulating glue; checking. According to the hard anodic oxidation pre-treatment technology provided by the invention, chemical oil removal and alkali etching procedures are not adopted so that corrosion risks are completely avoided; actual production proves that oxidation tint on the groove part of a product with a certain model can be avoided. By adopting the method, a condition that glue layers of the groove and blind holeparts are torn to fall off in a common partial hard anodic oxidation pre-treatment process so that the protection on the part becomes invalid can be avoided or a condition that alkali etching liquid is retained in a groove and a blind hole so that serious electrochemical corrosion on the part is caused can be avoided.

Description

technical field [0001] The invention belongs to the technical field of surface treatment, and in particular relates to a hard anodic oxidation pretreatment process suitable for the protection of grooves and blind holes. Background technique [0002] In the prior art, in order to achieve local hard oxidation of the aluminum material, an insulating glue is used to protect the non-oxidized area. However, in actual production, the parts with grooves and blind holes need to be protected. Since the adhesive layer of the grooves and blind holes is only attached around the surroundings, during the pretreatment chemical degreasing and alkali etching process, because the bath temperature is above 50°C, Coupled with the impact of hydrogen gas generated by alkali etching, the protective glue on the groove, blind hole, and adhesive layer will be separated from the substrate, and the sodium hydroxide solution in the alkali etching process will be poured into the gap between the groove, bl...

AI Technical Summary

Problems solved by technology

However, in actual production, the parts with grooves and blind holes need to be protected. Since the adhesive layer of the grooves and blind holes is only attached around the surroundings, during the pretreatment chemical degreasing and alkali etching process, because the bath temperature is above 50°C, Coupled with the impact of hydrogen gas generated by alkali etching, the protective glue on the groove, blind hole, and adhesive layer will be separated from the substrate, and the sodium hydroxide solution in the alkali etching process will be poured into the gap between the groove, blind hole, and adhesive layer. During the subsequent electro-oxidation process, the corresponding part will undergo intense electrochemical corrosion; or the glue layer will fall off during the alkaline corrosion process, which should cause the protection of this part to fail.