Nickel plating equipment

Nickel plating equipment

Nickel plating common fault and analysis:

Nickel plating equipment

Nickel plating equipment

Pinholes, pitting and peeling:

Electro plating coating layer has pinholes, pitting and peeling is the most common failure which mainly caused by the following reasons:

(1) Improper heat treatment process:

In the machining process, anti-rust oil, cutting fluids, lubricating oil, grease, grinding fluid, release agents and dust, grinding dust adhesion on parts surface mixed stick together, forming a thick dirt. If the heating treatment does not remove the dirt, while it will sinter to obstinate solid oil rust after degreasing and very difficult to clean, when plating, the bubbles attached on the coating layer forming gas hold-type pinhole.

(2) Poor treatment before nickel plating equipment:

Workpieces surface after heating treatment will inevitably adhere a layer of grease, when the dust accumulated on the surface and mixed with grease stick together, as a long time, it is extremely difficult to clean, so that the workpiece surface will form unconspicuous tiny oil spots, when nickel plating bubbles formed on will cause pinhole. In addtion, when using mesh belt resistance furnace for quenching, parts surface grease dirt and dust particle mix to stick together, sintering refractory solid grease, when nitrate tempering, the above grease again mix with nitro base salt to form stubborn hot polymer, while it is difficult to complete remove above durt in nickel plating equipment, in addition, hydrogen bubbles easily adhered on it, so that make the nickel plating coating layer appears pinholes and pits, and as the bubble grew bigger, the nickel electroplating layer will be automatically burst, resulting in peeling phenomenon.

Nickel plating coating layer peeling off:

Such failures have two main possible reasons:

1, Poor adhesion of the coating with substrate;
2, Nickel electro plating brittleness, small ductility.
If the heating treatment is improper, it will appear difficult to remove dirt or pre electro plating cleaning is not complete, the dirt mixed in between substrate and coating, making very poor binding force coating layer and substrate, in subsequent assembly processing, easy peeling off.
If improper ratio or poor quality brightener, PH value too high, and if the cathode current density too large and bath temperature too low, all will result in the reduction of hydrogen ions in the cathode, then the state of atomic hydrogen to penetrate into base metal and coating, make the base metal and the coating toughness decreases and cause “hydrogen embrittlement” phenomenon. In addition, when too much impurities and decomposition in the nickel solution, will also have result in “hydrogen embrittlement” phenomenon.

Poor corrosion resistance:

Because of high porosity of nickel plating layer, only when the coating thickness exceeds 25 micron, there is non-porous. Therefore, a thin layer of nickel electro plating alone can not be used as a protective coating, preferably double-nickel electroplating and multi-layer.

Green corrosion:

After nickel plating, antirust cutting fluid will be used for sealing treatment, after rust-proof cutting fluid dry, the product will be formed green negative phenomena.

Inside hole exposed copper:

Because bright nickel plating deep capacity less than cyanide plating, after nickel plating, the bright nickel plating layer can not completely cover inside hole for copper, so it will cause products unhealthy expose copper inside hole negative phenomena.

Nickel plating machine

Nickel plating machine

Nickel plating machine: Mainly used for decorative protective coatings. For iron matrix, nickel plating coating film is cathodic type coating. Because of its high porosity, so shall use copper layer as underlying or adopt multi-layer nickel plating. Nickel plating coating layer not bright from the ordinary plating solution, but easy to polish. Using Ssome brightener […]

Anodizing machine

Anodizing machine

Anodizing machine for aluminum:

Characteristic of pure aluminum:

Al is amphoteric metal, which is chemically active and easy to generate oxide in air, while aluminum oxide can inhibit further oxidation, the higher purity of aluminum, the more uniform film, and more excellent corrosion resistance. Easy to act with reducing agent. But anti-corrosion to oxidizing agent. Aluminum is passive state to concentrated nitric acid.

A Definition:

Aluminum in the ambient atmosphere will produce a layer of oxide film. Aluminum substrate attached to anode current to generate hard and transparent surface layer in electrolyte, this electro chemical reaction is called as “anodizing”, which is finished by anodizing machine.

B Features of anodizing:

Transparent, close to the glass; Insulation, anti-static; Changeable color appearance; Fully integrated with the aluminum surface and does not peel off. NOTE: Passivation is made for stainless steel surface treatment, as the same purpose to increase the corrosion resistance.

C Anodizing machine application functions:

Increase corrosion resistance; Increase abrasion resistance; Improve the adhesion of the substrate and coating; Provide an insulating surface; Insulation; Protection polishing surface and machined surface; Improve appearance. Note: After the oxidation can be painted, but generally do not suggest to do this process, because it is uneconomical. Usually to realize color when oxidation, basically except white, other colors are available by this deal, and it will not affect the film thickness (or the thickness of the substrate). These are functions of anodizing machine.

D Anodizing machine technical processes:

Anodizing machine

Anodizing machine

In briefly, anodizing machine divided into 2 big steps: Pre-treatment and After treatment.

Pre-treatment: Include degreasing, etching, chemical polishing, etc. Oxidation: once the surface is prepared, the oxidation film is built. After treatment: porous anodizing film can be colored in this stage. Sealing.

Chrome plating production line

1, Chrome plating production line proglgue:

Copper alloy with good features of corrosion resistance, excellent heat conductivity, excellent plasticity and certain mechanical strength, etc., where widely applied in the industrial field. Chrome plated copper alloy surfaces can increase hardware parts surface hardness, wear resistance, corrosion resistance and decorative.
However, unskillful technical process operation of brass plating chrome production line, will cause white stripes, spotted, shelling, blistering, poor bonding failure on brass surface, and poor brightness chrome plating: such as the surface of gray, dark, hair spray, etc., then effect the chromic plating layer quality.
Following, we’ll from chromium plating production practices based on brass, beryllium bronze alloy parts, to analyze, summarize the key factors of chrome plated copper alloy, then to improve quality of chrome plating.

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2, Material properties of the copper alloy and chrome plating process analysis and countermeasures:

Main material of brass is copper and zinc alloy, while zinc alloy is easy to dezincification corrosion and cracking, so when brass plating chrome production line in plating pre-treatment, need to prevent zinc dezincification.
HPb59-1 easy cutting brass contains a small amount of lead, in the conventional etching activation, it is difficult to dissolve lead, then often lead to chromium plate layer poor bonding. Copper is a copper alloy in addition to zinc, nickel elements, commonly used are copper tin alloy, as well as phosphor bronze, aluminum bronze, beryllium copper and so on. Beryllium bronze materials with high strength and hardness, and the fatigue limit, elastic limit, wear resistance, corrosion resistance are all very good, but also has heat conductivity, cold-resistant, non-magnetic, by the shock does not produce sparks, etc., so beryllium mostly to be used to manufacture elastic parts or wearable parts. Beryllium copper use copper as base material, containing beryllium: 1.7%~2.5%, and nickel: 0.2% ~ 0.5% and a trace titanium.
As an example QBe1.9 beryllium materials with a wide range of applications. The content of beryllium is 1.8%~2.1%, nickel: 0.2%~0.4%, titanium: 0.1%~ 0.2%, the balance being copper. Beryllium, nickel, titanium are elements of easy to passivation, beryllium bronze surface even in atmosphere air will quickly generate a dense layer of invisible passive film. And beryllium copper materials are generally required by quenching, aging processes such as heat strengthened, even with vacuum heat treatment, then surface oxide film will more denser. If parts of surface with oil, easier to generate grease, stains and so on.
So before chrome plating process, must select the appropriate pre-treatment process, make sure that the surface is in the activated state, to ensure chromium plating quality. Brass, beryllium in short time surface passivation easily when chrome plating energized, and even cause dissolve corrosion, which is the key reason of chrome plated brass quality.

3, Chrome plating production line pre-treatment:

The degreasing process before chrome plating of copper alloy not suitable for dipping alkali solution for a long time.

3.1, Brass parts corrosion activation:

Parts of the surface contain oxide or heavy black oxide film, must be pre-etching.
Temperature: room temperature;
Time: 1 ~ 5 min.
After descaling the pre-etching, to activate the surface by using of light etching.
For surface has smooth finish, minor oxide film parts, after degreasing process the surface oil purification can be fully activated in 10% sulfuric acid solution, then can be carried out for chrome plating operation.

4, Chrome plating equipment for brass:

Chrome plating production line for brass alloy parts using standard chromium plating processes. Copper alloy parts must be charged into baths, general should transmit small step cathode current power, especially for beryllium parts, cathode current density degree from 2 A/dm2 gradually rise to 5 A/dm2. Since cathodic hydrogen evolution, and the new ecological hydrogen atom precipitated with a strong reducing ability, can make the copper alloy surfaces passivation coating in particular beryllium bronze reduction and activation, that is very beneficial to improve the bonding strength of chromium plating equipment.

But be careful, charged into the tank, do not anode anti-plating, can effectively avoid passive film formed on the surface coating then to effect surface bonding force, and also avoid parts surface to dissolve corrosion to affect chrome plating quality.
Can adopt strike current (1.5~2 times compare to the normal current density) strike plating 30-60s, and this is particularly necessary for more complex shape parts.
Then resume normal current density chrome plating. In chrome plating process should always pay attention to the anode and cathode conductive good, should be appropriate to adjust the distance and position between the anode and cathode according to the shape of parts, in order to obtain a uniform layer of chrome, to make sure chrome plating quality.img_0038

Galvanized plating machine

Galvanized plating machine