Articles

Metal Etching Process

by xiaolong luo cnc machining shop
The application of chemical etching machine technology in ancient times was a kind of accident. On a certain day, people accidentally spilled acid on the metal and found that the acid can corrode and bite off the spilled place, and the bitten off place and the unbitten off place are formed. A three-dimensional feeling. Then people carefully record the situation. Later, a nonpolar acid with a strong acid type was discovered, that is, an anti-corrosion substance. After continuous experiments and improvements, it was gradually applied to real life, which brought great convenience to people's lives.

Around the 15th century, people mainly applied etching machine technology to the processing of armor. The craftsmen who made the armor put some anti-corrosion materials on the surface of the workpiece. It can be used for both marking and anti-corrosion. It is also possible that the rust spots formed by the damage of these protective layers acted as a mark, which inspired people to improve and gradually master the etching machine technology. At the beginning, the patterns on armor, helmets, weapons and other armors were difficult to engrave by hand. People had to find a quick and convenient way to process them. Through continuous experiments, they found that acid can corrode metals, and found that Materials that can resist acid and corrosion, finally began to use chemical corrosion technology in the production of armor patterns.

Regarding the application of etching technology to metal, the earliest written record appeared in a British manuscript in 15, which described an etching technology liquid prepared with salt, activated carbon and vinegar, and a A coating composed of linseed oil acts as a protective protective layer. During processing, the anti-etching machine technology material is first coated with the protection area pattern according to the finished workpiece style, and the metal in the exposed area will be corroded and bitten off by the acid. In the future, more advanced paraffin wax and natural resin will be used as the protective layer. When using this method, first apply paraffin wax to the entire material, and then scrape off the paraffin wax where it needs to be engraved and etched. This is the origin of step-type aluminum chemical etching or contour etching.

The possibility of removing one or more metallic materials with a liquid depends first of all on the potency of the compound, that is to say on the corrosivity of the compound. Only if this compound is sufficiently corrosive can it be used as a chemical raw material for etching machine technology. It can also be seen from this that the major development of chemical corrosion is the direct result of the development of chemical etching machine technology. In addition, the second decisive role is the discovery and development of anti-corrosion materials, because this controls the targeted local corrosion of the same metal before we can actually produce and process the products we need, so protective materials are very important. Since the corrosion processing technology has been available, the protection technology and the corrosion process method have always been the pipe fittings to ensure the processing quality. .

Technicians engaged in corrosion processing in ancient times did not have many methods to transfer images and texts to the metal surface to be corroded like we do today. The earliest method may be to use some paraffin, rosin, asphalt, etc., or natural organic materials such as beeswax and tung oil. According to records, in the 16th century, craftsmen who specialized in corrosion processing had to spend weeks or even months patiently to mash these materials in a certain proportion, and then blend them with liquid pitch or tung oil, or directly Heated and melted to make a protective coating. Then use a brush to carefully apply the protective paint to the surface of the entire part that needs to be corroded, and after drying or cooling and hardening; then use a hard object such as a needle or a scraper to make a pattern on the protective layer, and then use the original method for corrosion processing. We can imagine how they used paraffin and other natural room-temperature solid resins to build barriers around the corroded parts, and then slowly added acid to the corroded parts. We can estimate the various difficulties that these craftsmen who are specialized in corrosion will encounter, such as: the adhesion of the corrosion protection layer is not enough, and when the corrosion depth requirement has not been reached, the corrosion protection layer may come off in whole or in part. It needs to be polished by hand to remove all corrosion burn marks; the anti-corrosion wall built by natural resins such as paraffin cannot prevent acid spillage well, and the outer edge or other parts of the parts are corroded, and these Parts are machined and valuable before being corroded, and thus carry great risk. With the development of other auxiliary technologies and organic materials, non-metallic materials can be used to make large containers, and at the same time, the use of anti-corrosion coatings to fully protect other parts of the parts has gradually been mastered. At this time, the parts can be directly immersed in one foot. .

Etching process flow of etching mesh production:

From the characteristics of the etched net, we can know that the etched net is all produced and processed by metal etching, because the etched net has very dense small holes and burrs and wind are not allowed, and the stamping process cannot do it. This density and smoothness. The process of etching the net is to transfer the image by exposure and development, so the production and processing of the etching net requires six sets of equipment to produce and process through six processes. The six sets of equipment are: coating machine, oven, exposure machine, Developing machine, etching machine, ultrasonic cleaning machine. Production and processing are realized through the performance of these six equipments acting on their corresponding processes.

Metal corrosion technology is mainly developed from three aspects: 1. The discovery of metals and the development of smelting technology; 2. The discovery of various corrosive agents; 3. The discovery of anti-corrosion materials.

Four steps of metal chemical etching processing technology:

1. Cleaning:

Its purpose is to clean all kinds of stains on the surface of the rough parts to be corroded, so as to ensure that the adhesion between the anti-corrosion layer and the metal surface is uniform, and the etching speed is uniform. Commonly used cleaning methods are:

Organic solvent cleaning, alkaline chemical cleaning, acidic chemical cleaning, ultrasonic cleaning, electrolytic cleaning, etc. During use, it can be selected according to the type of metal material of the part and the degree of pollution on the surface of the part.

2. Anti-corrosion treatment:

Its purpose is to protect those surfaces that do not need to be corroded, so that the metal surface that needs to be corroded is completely exposed, and corroded by an etchant that is compatible with the metallic material. This process requires: the anti-corrosion material should be firmly adhered to the metal surface, and the anti-corrosion layer will not fall off during the entire corrosion process. Anti-corrosion treatment mainly includes: screen printing anti-corrosion technology, photographic chemical anti-corrosion technology, pad printing anti-corrosion technology, graphic electroplating anti-corrosion technology, laser lithography anti-corrosion technology and scribe anti-corrosion technology, etc.

3. Corrosion processing

It is a process in which the corroded metal parts are prepared with anti-corrosion graphics according to the requirements of the drawings, and then put into the corrosion tank for corrosion processing. In this process, the main controls are: etchant concentration, etching temperature, etching time, etching pressure, etc. Metal corrosion processing can be divided into five basic types according to the drawing requirements, namely: overall corrosion, selective corrosion, multi-step corrosion, taper corrosion and chemical cutting blanking. Metal corrosion does not require anti-corrosion treatment, and parts can be corroded after cleaning.

4. Remove the corrosion protection layer:

After the parts are corroded, use solvent, lye or other cleaning agents to remove the anti-corrosion layer on the surface of the parts.

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About xiaolong luo Advanced   cnc machining shop

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Joined APSense since, May 5th, 2019, From Dongguan, China.

Created on May 24th 2023 08:07. Viewed 157 times.

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