Surface treatment of extruded magnesium

In the application products of magnesium alloy, pressure machining products, casting products and non-structural applications are three major trends. Since the industrialization of magnesium application, magnesium in metallurgical industry (preparation of aluminum alloy, steel desulfurization, ductile iron, etc.) in the application of 50%-65%, processing magnesium and magnesium alloy semi-finished products (plate, strip, tube, bar, profile) material accounted for a very small proportion, only 1%-1.6%, extrusion material (tube, bar, profile) accounted for a smaller proportion, only 0.4-0.8%.Therefore, the amount of extruded magnesium required for surface treatment is small each year. The surface treatment methods of extruded magnesium include oxidation coloring, anodic oxidation, electroplating and so on.

Preparation and management of tank liquid of magnesium

Calculate the chemical products needed according to the volume of the tank, add water to 1/2 volume, add the chemical products one by one into the tank, heat the oil removal tank and the oxidation tank, turn on the fan, stir, and turn on the fan for the pickling tank and the light washing tank at room temperature, stir. After stirring, add water to the specified volume, then stir evenly, sample analysis, test oxidation, qualified rear can be formal production. Chemical analysis of tank liquid composition should be carried out periodically during use.

Oxide film defect repair of magnesium

The oxide film on the surface of the extruded material should be uniform and firm. If it is unqualified, it can be repaired as follows:

Thoroughly remove the unqualified film layer and reprocess.

The defective oxide film is partially removed and then colored with complementary color solution. The commonly used complementary color solution is shown in Table 2.After cleaning oil with gasoline or industrial alcohol, gently polish it with glass abrasive cloth to expose clean magnesium, blow the dust with compressed air, wipe the surface with gauze soaked in wine semen, dry it with glass stick or wood stick of brocade yarn or cotton, dip in oxidation solution and rub it on the surface repeatedly for about 35s, dry it.