What are the main surface treatment processes for zinc-aluminum alloys? The significance of zinc-aluminum alloy surface treatment technology is: through the surface treatment significantly soft improve product quality; save precious materials, material surface composite; solve the problem that a single material can not be solved; repair the overall advantage of good energy-saving, material-saving effect.
Zinc and aluminum alloy surface treatment is divided into the following categories: powder coating, baking paint, passivation (including phosphating, chromating, film) treatment, anodic oxidation, polishing, plating, powder coating, electrophoresis, sandblasting, shot blasting and so on.
First, powder spraying (i.e. powder spraying): powder spraying equipment is used to spray powder coating to the surface of the die casting, under the action of electrostatic force, the powder will be uniformly adsorbed on the surface of the die casting, forming a powdery coating. Powder coating after high temperature baking leveling curing, into powder coating of different kinds of effect of the coating; powder coating spraying effect in mechanical strength, adhesion, corrosion resistance, aging resistance, etc. is better than the spraying process, the cost is also lower some. Powder coating is divided into outdoor powder and indoor powder. The texture can be adjusted to a variety of various effects, like glossy, sand, foam and so on.
Second, baking paint process: baking paint process is sprayed with aluminum alloy after phosphating, spraying and then baking, so that the coating is not only anti-corrosion and bright wear-resistant, not easy to fall off. Surface pretreatment: degreasing, washing, rust removal, washing, table adjustment, washing, phosphating, washing, washing, drying. Baking paint pretreatment is designed to get a good coating, due to the above stamping parts in the manufacturing, processing and handling, preservation of the period there will be grease, oxides, rust, dust, rust and corrosion on the surface, if not removed will have a direct impact on the performance of the film, the appearance of the film, etc., so pre-treatment in the coating process occupies a more important position.
Third, passivation treatment: aluminum alloy die casting surface oxidation, suitable for doing conductive oxidation, aluminum or aluminum profiles, suitable for doing anodic oxidation. Aluminum alloy die casting oxidation color generally have the original color, sky blue. Anodic oxidation is carried out in the case of high voltage electricity, it is a kind of electrochemical reaction process; conductive oxidation does not need to be electrified, but only need to be soaked in the potion on the line, it is a pure chemical reaction. Anodic oxidation takes a long time, often dozens of minutes, and conductive oxidation only takes a few dozen seconds.
Fourth, anodic oxidation aluminum oxidation treatment anodic oxidation is in the case of energized aluminum parts into the electrolytic tank, die casting for the anode, on the surface to produce a layer of dense aluminum oxide film layer; anodic oxidation film, although good protective, wear-resistant, but its resistance is high, not conductive; aluminum and aluminum alloys by the conductive oxidation process obtained by the oxidized film has a conductive property, which is its performance, and the film layer of protective and decorative properties. Good performance.
Fifth, sandblasting: spray a layer of fine sand on the surface of aluminum alloy products to enhance the friction coefficient of the contact surface, which can enhance the reliability of the connection. The sand has coarse and fine, and the grain is also very different.
