>>   Electroforming Processing

(1) Basic principle of electroforming

In some metallic ion electrolyte, take the core mold as the negative pole, and pass through certain profile direct current of low pressure so as to enable the metallic ion to obtain the electron to return to original state and accumulate metal unceasingly in the negative pole. This process is called electroforming. When nickel is being electroformed, the main reaction is that the nickel ion obtains the electron in the negative pole and is returned to nickel.

Electroforming is a kind of electrolysis processing craft and follows the Faraday's law of electrolysis. Under the steady state, electrons flowing to the negative pole through the outside line participate in the reaction. But as a result of the existence of electrode side reaction, the real weight is smaller than the theoretical weight. It must calculate according to the current efficiency.

Electroforming duplicates precisely some parts of complex or the special shape according to the principle of metal electrolytic deposition. It is the special application to galvanization. Electroforming was invented by the Russian scholar Б .С.Yakbe in 1837. At first it was mainly used in duplicating the metal artware and the printing version. In the late 19 century it was started to be used in making the phonograph record die. Later the application scope expanded gradually.

The above picture shows the basic principle of electroforming. Take the master form made in advance according to the needed shape as the negative pole and electroforming material as the anode. Next put them in the metal salt brine the same material as anode material, and then pass through the direct current. Under the electrolysis, the surface of the master form deposits gradually the metal electroforming level. After achieving requiring thickness, take it out from the solution and separate the electroforming level and the master form to obtain the metal duplicate correspondent with the master form shape. Metals that can be used to electroform are usually the copper, the nickel and the hard. Sometimes they are cobalt – tungsten such as golden, the silver, platinum nickel - cobalt, alloy. But the nickel is used the most widely in electroforming. The thickness of electroforming level is generally between 0.02 and 6 millimeters. It also amounts to 25 millimeters. There are only several microns between electricity casting and master form in error.

Electroforming is mainly applied to precisely duplicating tiny, complex parts of special shape that can't be processed in other methods, for example the printing version for manufacturing paper money and the postage stamp, the phonograph record die, the type matrix, the metal artware duplicates, the reflective mirrors, the type blocks of roughness on surface, the meshes with tiny holes, the dial plates, electric poles processed by electric spark, the highly accurate diamond emery wheel substrates and so on.

The master form material has the gypsum, the wax, the plastic, alloy of the low melting point, the stainless steel and the aluminum and so on. The master form is generally made by casting, cutting or carving and so on. Precise tiny mesh or complex design can be made by making lithograph plates with the photographic technology. The master form of nonmetallic material must pass through leads electrification processing. The methods include painting electric conduction powder, chemical coatings and vacuum coatings and so on.

First process the master form of metallic material to form the oxide film on the surface or spread the graphite powder. It's convenient to peel electroforming level.

Electroforming equipment is composed by electroforming trough, the direct-current power supply (12 volts generally, several hundred to several kiloamperes), electroforming solution' installments of steady temperature, agitation, circulation and filtration. Electroforming solution is peroxide solution with electroforming metallic ions including sulfate, the sulfamate, the fluoborate, the chloride and so on. The major defect is low efficiency. The thickness of electroforming metal level is generally 0.02 ~ 0.05 millimeter per hour. Use highly concentrated electroforming solution, strengthen agitation measures and increase the solution temperature properly. It can enhance the current density, reduce electroforming time and raise electroforming efficiency. This method has obtained the application in the nickel electroforming.

(2) Raw material of electroforming

nickel

thionamic acid nickel

the boric acid (cushion)

the nickelous chloride (activation)

(3) Typical electroforming craft

electroforming copper

electroforming irons

electroforming nickel

electroforming nickel cobalt alloy

electroforming nickel manganese alloy

electroforming gold

electroforming silver

Electroforming Craft

Electroforming craft refers to the technology of fast electric deposition of single metal, the alloy or the metal-based compound materials at a high speed in the heteromorphous temporary mold (mold cavity either force plug) The electrically deposited material includes copper, nickel, iron, cobalt, tungsten, imitative golden copper alloy, iron-based alloy, nickel-based alloy as well as copper and nickel-based metallic compound material distributing wear-resisting Al203, Sic3> diamond and so on. This technology provides mold design and manufacture, electroforming installment design (except power equipment), electroforming solution formula electroforming craft, removing inner force of electroforming parts as well as micro densification processing.

Major technique performance or technical specification:

Electroforming speed: (taking electroforming nickel for example): 5- 300μ/h; electroforming (nickel) level intensity: σb=340-600MPa; Degree of hardness: Hv100-220; the size precision of surface contacting with the core mold (cavity): ±1μ, thickness of electroforming level: 0.5mm

We produce wave pipes, special pipes in the corrugated pipe and the refrigerator and air conditioning, rubber and plastic parts stamping films, printing drum; sealing-in and the connection between metals difficult to weld, carbon bits of oil well, diamond cutting tools involving in machinery, electron, petroleum, light industry, chemical industry and so on. The batch is big and a large number of products are vulnerable. They are widely used.

With the most advanced South Korean technology, we are mainly engaged in product labels of metal fission, ultra-thin product labels, ultra-thin metal trademark, carving characters on plates and production and sale of heteromorphous parts.

New metal electroforming product labels are also called metal pastes or product labels of the metal fission. This technology stems from Japan , South Korea . It has been spreaded to our country in recent years. Electroforming product labels are deposition-formed with the highly accurate models. The craft is unique. The technique content is high. The material is precious. The products are fine and magnificent with intense vision and upscale image. They are easily pasted. The bottom bush enhances product scale effectively. They can be pasted on soft and hard material such as lumber, plastic, paper, quartz and metal. Nowadays domestic high-grade commodities have adopted them.