7075 Aluminum Alloy is a high quality aluminum alloy material that is widely used in various industries due to its excellent strength, hardness and corrosion resistance. In many applications, the quality of a product's appearance has a significant impact on the product's market competitiveness, so surface treatment, such as polishing, of 7075 aluminum alloy has become an important means of improving the aesthetics and value of the product.

First of all, let us understand the basic characteristics of 7075 aluminum alloy. 7075 aluminum alloy belongs to the alloy of aluminum, copper, magnesium and silicon, of which copper is its main alloying element, accounting for 6.8%-7.8% of the total alloy content. This alloy has good tensile strength, fatigue strength and corrosion resistance, and is suitable for manufacturing parts subject to high stress and high load. Meanwhile, 7075 aluminum alloy has good welding properties and machinability, but relatively poor polishing properties.

So, why do we need to polish 7075 aluminum alloy? Polishing treatment can improve the surface quality of 7075 aluminum alloy and make its surface smooth and beautiful. Polished 7075 aluminum alloy has the following advantages:

1. Improve the appearance quality: the polished 7075 aluminum alloy has a high surface finish and bright color, which can improve the overall aesthetics of the product and increase the market competitiveness.

2. Increase corrosion resistance: Polishing treatment can remove the tiny defects and impurities on the surface of aluminum alloy, so as to improve its corrosion resistance and prolong the service life of the products.

3. Improve welding performance: Polishing treatment can optimize the welding performance of 7075 aluminum alloy, reduce welding defects in the welding process and improve welding quality.

4. Improvement of coating adhesion: Polishing treatment can improve the adhesion of 7075 aluminum alloy surface coating, make the coating more uniform and firm, and prolong the service life of the coating.

How to polish 7075 aluminum alloy?7075 aluminum alloy polishing process mainly includes the following steps:

1. Degreasing: Before carrying out polishing, it is first necessary to remove the oil, oxide skin and other impurities on the surface of aluminum alloy to ensure the polishing effect. Alkaline cleaning agent or organic solvent can be used for cleaning.

2. Rough polishing: use coarse abrasives (such as silicon carbide sandpaper) to initially polish the surface of aluminum alloy to remove surface scratches, oxidized skin and other defects. In the rough polishing process, pay attention to moderate pressure to avoid excessive abrasion.

3. middle casting: on the basis of rough casting, the use of medium abrasive (such as aluminum oxide sandpaper) for further polishing, so that the surface is more smooth. In the process of medium polishing, we should control the polishing speed and pressure to avoid scratches.

4. fine polishing: the use of fine abrasives (such as aluminum oxide sandpaper) for fine polishing, so that the surface to achieve a mirror effect. Fine polishing process, to try to slow down the polishing speed, light pressure polishing pad, to avoid excessive wear.

5. Polishing paste application: in the polishing process, can be properly coated with polishing paste to improve polishing efficiency and surface quality. Polishing paste has lubrication, cooling and anti-corrosion effect, which can reduce the wear and heat generation on the surface of aluminum alloy.

6. Cleaning: After polishing is completed, use water to clean the surface of aluminum alloy and remove the residual polishing paste and impurities.

In short, by polishing 7075 aluminum alloy, it can improve its surface quality, corrosion resistance and coating adhesion, so as to enhance the market competitiveness of the product. In the actual operation process, it is necessary to master the polishing speed, pressure and the use of polishing paste to achieve the best polishing effect.