Method for forming nanoscale porous membrane layer on pure aluminum surface

Abstract

The invention discloses a method for forming a nanoscale porous membrane layer on a pure aluminum surface. The method comprises the following steps of: (1) pretreating the pure aluminum surface; (2) placing the pure aluminum pretreated in the step (1) as a positive pole and a platinum electrode as a negative pole into an electrochemical polishing solution, enabling the spacing between the positive pole and the negative pole to be 50-70mm, and carrying out electrochemical polishing for 10-90s at the current density of 80-160mA / cm<2> under the environment temperature so as to form the nanoscale porous membrane layer on the pure aluminum surface, wherein the electrochemical polishing solution consists of 1,2-propylene glycol and perchloric acid based on the volume ratio of (9:1)-(2:1); and (3) cleaning and drying the pure aluminum subjected to electrochemical polishing in the step (2). According to the method, the nanoscale porous membrane layer is formed on the pure aluminum surface through electrochemical polishing, so that the production cycle of porous positive-pole alumina membranes is greatly shortened. Besides, the obtained nanoscale porous membrane layer has the advantages of large range, well-aligned height, and the like.

Description

technical field [0001] The invention belongs to the technical field of metal surface treatment, and in particular relates to a method for forming a nanoscale porous film layer on the surface of pure aluminum. Background technique [0002] Aluminum is a relatively active metal. It can naturally form an oxide film with a thickness of several hundred nanometers in the air. This oxide film is amorphous, thin and porous, and has low mechanical strength, which cannot meet the requirements of functional applications. [0003] In order to obtain an oxide film layer with special functions, the aluminum surface must be treated, usually in an electrolyte, using aluminum as an anode for electrolytic treatment, so as to obtain an oxide film on the aluminum surface. According to different electrolytes, dense (or barrier) anodized aluminum oxide film and porous anodized aluminum oxide film can be obtained respectively. [0004] The dense (or barrier) anodized aluminum oxide film is obtain...

AI Technical Summary

Problems solved by technology

However, this electrochemical polishing method obtains a self-organized structure of nanoscale stripes, and from the growth mechanism of the porous anodized aluminum oxide film, although pores can also be formed along the direction of the stripes, the pore density and order are seriously affected.

[0009] In addition, other methods for forming nanoscale porous membranes on metal surfaces, such as photolithography and electron beam etching, are generally unable to be applied industrially due to complex processes and high cost.

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