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.