Foreword: This article sorts out and summarizes the rare processes of metal surface treatment, taking aluminum and aluminum alloys as examples.

 

The industrial design of products has shown a trend of diversification and individualization, and the use of new materials, new processes, and new technologies is not uncommon. Many products use metal materials to better express product quality, enhance the product's sense of weight or honor, and highlight brand value. Rare metal materials include stainless steel, aluminum and aluminum alloys, magnesium alloys, and zinc alloys. Among them, aluminum and aluminum alloys are easy to process, and the methods of appearance treatment are generous and widely used. Zinc and magnesium alloys are also commonly used. In the case of aluminum and aluminum alloys, the following methods are mainly used for appearance treatment.

1. Polishing: Grinding and polishing constitute a mirror effect
Polishing refers to the application of mechanical, chemical or electrochemical effects to reduce the surface roughness of the workpiece to make the surface of the workpiece bright and smooth. The polishing process mainly includes mechanical polishing, chemical polishing and electrolytic polishing. Among them, mechanical polishing refers to the use of polishing processes (rough grinding, fine grinding) and polishing processes to stop treatment on metal materials, and finally obtain a smooth, bright and mirror-like surface Appearance: Chemical polishing refers to the use of chemical solutions to stop soaking to remove the surface oxide scale to achieve a bright effect; electrolytic polishing is a way to stop the anode treatment of metal parts by electrolysis to improve the surface finish. For aluminum and aluminum alloys, mechanical polishing and electrolytic polishing can be used to stop the treatment, which can achieve an effect close to a stainless steel mirror surface, which makes the product high-end, fashionable and complicated.

2. Sandblasting: form matte pearl silver surface, etc.
The sandblasting process mainly refers to the process of clearing and roughening the metal surface by the impact of high-speed sand flow. The surface of the workpiece can obtain a certain degree of cleanliness and different roughness, so that the mechanical properties of the workpiece surface can be improved to a certain extent, and the fatigue resistance of the workpiece can be improved. Sex. The adhesion of the metal and sandblasting coating must be guaranteed, the coating film is durable and beautiful in appearance. The sandblasting process can be seen in many products, such as some TV cabinets or middle frames, and some shells or middle frames of consumer electronic products are compared to the sandblasting process.

3. Electroplating: cover a layer of other metal layers
Electroplating refers to the process of applying a thin layer of other metals or alloys on the surface of some metals using the principle of electrolysis. It is a process of applying electrolysis to attach a layer of metal film to the surface of the metal or other materials. It can be ineffective and avoided. Metal oxidation (such as rust) improves wear resistance, electrical conductivity, reflectivity, corrosion resistance (copper sulfate, etc.), and also makes the product beautiful.
4. Drawing: a similar satin effect
Metal wire drawing is the manufacturing process of repeatedly scraping aluminum plates out of lines with sandpaper. The typical process includes three parts: deesterification, sand milling and water washing. Metal wire drawing is rare and can complete straight wire drawing, spiral wire drawing, spiral wire drawing, chaotic wire drawing, etc. Using the metal wire drawing process, it can show the thin silk marks visible to the naked eye on the metal surface, which is expressed as the fine hair luster in the metal matte, making the product both fashionable and technological.

5. Spraying: cover up other non-metallic coatings
Metal spraying is a data maintenance technology that uses a high-speed particle stream of molten metal to spray on the surface of the substrate to produce a coating. Metal spraying is mostly used for mechanical repair, mechanical parts that resist intense chemical media, improve the wear resistance of mechanical parts, and improve other friction functions of mechanical parts. The spraying equipment in the machinery industry includes arc spray gun, flame spray gun, plasma arc spray gun, plasma spray welding and so on. Among them, arc spray guns are commonly used, which are suitable for metal wire spraying; flame spray guns are mainly used for metal wire, cermet and refractory oxide spraying; plasma arc spray guns and plasma spray welding are suitable for spraying various powders.
The choice of spraying method and spraying materials is very important, in addition, the pre-spray and post-spray treatment cannot be ignored. In some metal products, the spraying treatment is usually stopped to increase the adhesion of the metal surface before stopping the functional spraying, and then the bonding layer (nickel, molybdenum, etc.) is stopped, and the quality inspection of the sprayed layer is initially stopped after spraying. And stop the necessary blockade treatment and corresponding finishing.

6. Anodizing: electrochemical oxidation of metals or alloys
Anodizing refers to the electrochemical oxidation of metals or alloys. It is the process of forming an oxide film on aluminum products (anode) by applying current to aluminum and its alloys in the corresponding electrolyte and specific process conditions. The effect of anodizing is self-evident. It can restrain the defects of aluminum and aluminum alloys in appearance and wear resistance, and can also extend the service life of aluminum and aluminum alloys and add visual effects of product appearance. Anodizing has once become an important part of the surface treatment of aluminum and aluminum alloys, and the process has been very mature.
Nowadays, there is a two-color anodizing process, which refers to stopping anodizing on a product and giving different colors to a specific area, which can better express the high-end and common style of the product through two-color comparison. It's just that the two-color anodizing process is complicated and the cost is higher.

Seven, highlight cutting
High-gloss cutting refers to the use of machining equipment such as fine-engraving machines to reinforce specific tools (such as diamonds) on a high-speed rotating (normal speed of 20000 rpm) of the main shaft of the fine-engraving machine to stop cutting parts, so as to highlight parts of the product surface area. The brightness of the cutting highlights will be affected by the speed of the milling drill. The faster the speed of the ordinary drill, the brighter the highlights will be lost. On the contrary, the cutting surface will be darker and more likely to occur.
The high-gloss cutting process is often used in mobile phone frames that use metal materials. The metal frames of some high-end products also use high-gloss milling processes. If combined with anodizing and wire drawing processes, the entire product will be full of fashion and technology. .