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So beautiful aluminum alloy surface treatment process

Release time:

2020-04-13 10:26

More and more aluminum materials are used in various products.,Aluminum material can better reflect the product quality, highlight the brand value, and because of its easy processing, good viewing angle effect, rich surface treatment, the first should be adopted by various manufacturers, the followingAnn.To introduce you to the commonly used products of aluminum surface processing technology and oxide film appearance quality inspection related knowledge.

1.Aluminum alloy surface treatment process

1. Oxidation

Aluminum alloy surface is easy to generate a very thin layer of aluminum oxide film (0.01-0.02um), there is a certain degree of corrosion resistance. However, because this oxide film is amorphous, the surface of the aluminum piece loses its original luster. Aluminum alloy products are usually subjected to special oxidation treatment. Before oxidation treatment, the surface of the products is cleaned by chemical and physical methods to expose the pure metal substrate to facilitate the smooth oxidation and coloring, so as to obtain an artificial film with a firm combination with the substrate, color and thickness to meet the requirements and has the best corrosion resistance, wear resistance, weather resistance and other good properties.

Oxidation process: degreasing → alkali etching → anodic oxidation → activation → dyeing → sealing

 

2. Secondary oxidation

There are many text symbols on electronic products that are raised. There are two ways to make this effect: secondary oxidation and stamping.

Generally speaking, the secondary oxidation of convex characters is to obtain a bright surface effect, and the font can be very small. Because the material is removed by corrosion, the height is generally relatively small, and if it is too high, aluminum will be wasted.

 

3. Surface drawing

According to the decorative needs of aluminum alloy parts, the surface can be made into several surface drawing effects such as straight lines, random lines, threads, ripples and swirls.

4. Sand blasting

Sand blasting is to obtain a film light decoration or a fine reflective surface to meet special design needs such as soft gloss. At the same time, it can make the combination of printing material and substrate more firmly. Sand blasting is usually carried out in a special sand blasting machine. According to the requirements of the sand surface thickness, select the appropriate mesh of quartz sand, spray into the appropriate sand surface. Uniform and moderate sandblasting can basically overcome the common defects of aluminum surface.

 

5. Highlights

Highlight is the effect of milling on the machine tool with a tool on the edge of aluminum parts, convex characters and other places that need to be conspicuously treated. The usual effect has bright edges (C corner), bright faces,CDTattooed.

Highlight is a relatively backward process for aluminum parts.

Bright edge treatment is generally carried out on flat aluminum parts. Before highlighting, more precise fixtures should be processed, and holes should be opened in the fixtures and vacuum sucked. The angle of the bright edge C angle is determined by the selection of milling cutters with different angles, and the trajectory of the bright edge of the aluminum part is input.CNCThe milling cutter follows this trajectory to complete the machining. When designing aluminum parts, the area should not be too small, and enough vacuum adsorption area should be left, otherwise the aluminum parts cannot be absorbed during processing, and large and small edges will also appear. Bending treatment after bright edge treatment may cause damage to aluminum parts; if the edge is bright after bending, the edge width will be different.CDThe grain is a series of concentric circles drawn on an aluminum piece with a milling cutter.

 

6. Spraying, printing

Aluminum alloy spraying, printing and plastic phase similar. Spraying paint (liquid) and powder (solid), printing with silk screen and pad printing, printing without UV oil.

 

2.Appearance quality inspection of oxide film after anodic oxidation of aluminum

① Aluminum alloy anodized parts surface, there should be a layer of uniform oxide film, due to aluminum alloy composition, oxidation treatment method, sealing treatment method, oxide film color is not the same. On the whole oxidized surface, except for the fixture mark, there shall be no such defects as scratch, crush, scratch, electric burn, local corrosion and oxide film crack, or loose oxide film that can be wiped off by rubbing with fingers.

② The colorless oxide film oxidized by sulfuric acid anodic oxidation is not allowed to have other variegated colors, or the surface is not well prepared and the surface is flowery, black, dark lines and other phenomena, or defects caused by poor sealing. Sulfuric acid anodic oxide film should be orange yellow after being sealed by potassium dichromate, and no white or pale color due to poor sealing is allowed. The colored oxide film should be brightly colored and meet the requirements of the dyeing template. Not allowed: bright spots, black spots, uneven color phenomenon.

 

The oxalic acid anodic oxide film due to the use of different types of current, film thickness is different, the surface from yellow green to dark brown.

 

④ Chromic acid anodized film generally from gray to gray black, not allowed: yellow spots, white spots, local film red, black state.

The above is for reference only, the specific subject to the actual!