Anodic oxidation method of spare part containing blind hole

Abstract

The invention discloses an anodic oxidation method of a spare part containing a blind hole. The method comprises the following steps: effective depth region test, sand blasting, surface pretreatment, anodic oxidation and subsequent procedures, wherein the effective depth region test comprises the following processes: providing a reference electrode in the blind hole, and testing potential or current density values of different depth positions in the blind hole, so as to obtain an effective depth region; the sand blasting comprises sand blasting on the effective depth region; surface pretreatment comprises the following processes: carrying out degreasing, alkaline etching and pickling on the spare part after the sand blasting step; anodic oxidation comprises carrying out anodic oxidation according to the anodic oxidation process; and the subsequent procedures are carried out after the anodic oxidation step. According to the method, potential or current density distribution at different depth positions in the blind hole can be effectively smoothed; and the uniformity of the thickness of an anodic oxidation film in the blind hole is improved.

Description

technical field [0001] The invention relates to the field of anodic oxidation, in particular to an anodic oxidation method for parts containing blind holes. Background technique [0002] In the field of mechanical manufacturing, blind holes with a diameter of 0.3 mm to 3 mm are generally called small holes, and blind holes with a hole depth exceeding 5 times the hole diameter are called deep holes, and blind holes that meet these two conditions are called small holes. Diameter deep hole, referred to as small deep hole. Small deep holes are widely used in internal combustion engine oil pump nozzles, various valves, automobiles, electronics, micro-machines, aviation, aerospace and military fields. [0003] In practical applications, some parts of pure titanium, titanium alloy, pure aluminum or aluminum alloy need to be anodized, and when these parts have small deep hole design, many difficulties will be encountered in anodizing, the most important of which is Two problems: o...

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Problems solved by technology

[0003] In practical applications, some parts of pure titanium, titanium alloy, pure aluminum or aluminum alloy need to be anodized, and when these parts have small deep hole design, many difficulties will be encountered in anodizing, the most important of which is Two problems: one is the uneven distribution of potential or current density in the hole; the other is that the diffusion of the solution in the hole is limited, and the solution exchange and heat dissipation are difficult

[0005] However, the above methods have unsatisfactory anodic oxidation effects in blind holes, and are difficult to apply to small deep holes: adjusting the clamping direction of the workpiece cannot fundamentally solve the uneven distribution of voltage and current density on the inner wall and bottom of the blind hole of the part and the difficulty of solution exchange. and other problems; increasing the oxidation voltage and prolonging the oxidation time may cause over-burning of other surfaces except the blind hole, unqualified size, and waste of energy; increasing the auxiliary cathode or other auxiliary solution circulation device, the device needs to be placed in the blind hole Among them, in order to keep a certain distance between the device and the wall and bottom of the blind hole to avoid short circuit or affect the distribution of power lines, the blind hole must have a certain width, and this requirement is obviously not suitable for the small deep hole design on the part

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