Sulfuric acid anodizing process method for precise aluminum alloy parts

Abstract

The invention discloses a sulfuric acid anodizing process method for precise aluminum alloy parts. The method comprises the following steps of before sulfuric acid anodizing, performing size reservation, performing size reservation on the basis of original deviation for shaft or hole size parts with different tolerances, then performing oil removal by using an organic solvent, and performing alkali washing: specifically, the aluminum alloy parts are put into a NaOH (50-70) g / L solution for alkali washing at the temperature of 50-70 DEG C for 0.5-2 minutes; washing with hot water and then washing with cold water, flushing with a high-pressure water gun, clamping, and anodizing: H2SO4: (180-230) g / L and Al2 (SO4) 3.18 H2O: (10-20) g / L, wherein Al+3 does not exceed 25 g / L; performing cathodic treatment: a Pb-Sb alloy, 90%-94% of Pb and 10%-6% of Sb; and performing deionized cleaning, filling, blow-drying and inspection. Through size reservation before anodizing and related operation process refinement, it is guaranteed that precise part anodizing production can be conducted on the parts, the anodizing size qualification rate of products with the tolerance ranging from 0 mm to 0.015 mm is 100%, and the anodizing size qualification rate of products with the tolerance ranging from 0 mm to 0.012 mm is 98% or above.

Description

technical field [0001] The invention relates to the technical field of anodic oxidation of aluminum and its alloys, in particular to a sulfuric acid anodization process method for precision aluminum alloy parts. Background technique [0002] Aluminum and its alloys are one of the most widely used metals, which have the advantages of good electrical conductivity, fast heat transfer, low density, high specific strength, and easy molding. However, aluminum and its alloys have disadvantages such as low hardness, non-wear resistance, prone to intergranular corrosion, and difficult welding, which affect their application range and service life. In order to increase the corrosion resistance of aluminum and aluminum alloys, anodic oxidation is performed on aluminum and aluminum alloys. The anodic oxidation of aluminum and aluminum alloy is to use aluminum and aluminum alloy parts as anode and lead plate as cathode to electrolyze in sulfuric acid, oxalic acid, chromic acid and other...

AI Technical Summary

Problems solved by technology

[0003] Generally, for precision parts, chromic acid anodization is often used for treatment, but due to its high temperature, the bath contains chromic anhydride, that is, Cr +6 , have great harm to human body and environment

However, the thickness of the sulfuric acid anodized film layer is relatively large, and the production operation of precision parts cannot be carried out.