As we all know, magnesium alloys are based on metal magnesium and formed by adding some other elements. The alloy elements added in magnesium alloys mainly include AL, Zn, Mn, Si, x, Cu, Li and some rare earth elements. Magnesium alloys can be classified not only by alloy composition, but also by processing methods and performance applications. Today, Nuoba promised to explain the classification of magnesium alloys and what are the magnesium alloy processing surface treatments?
Processing of magnesium alloy parts
Classification of magnesium alloys:
1. Classification according to magnesium alloy composition:
According to chemical composition, it can be divided into Mg Mn, Mg AL Mn, Mg Al Zn Mn, Mg Zn Zn, Mg Zr, Mg Zn Zr, Mg Re Zr, Mg Ag Re Zr, Mg Y-Re Zr based on the five main alloy elements Mn, Al, Zn, Zr and rare earth.
2. Classification according to the processing method of magnesium alloy:
According to the processing method, magnesium alloys can be divided into three categories: cast magnesium alloys, wrought magnesium alloys and hot-dip magnesium alloys. Casting and deformation are two common types. These two types of alloys have great differences in composition and metallurgical structure and properties. Cast magnesium alloys are mainly used for die casting transportation equipment, machinery, electrical and electronic products and other spare parts. Die cast magnesium alloy workpieces have high casting efficiency, excellent surface quality, fine and uniform grains, and can produce workpieces with thin walls and complex shapes. Wrought magnesium alloys are mainly used for forging and extrusion, with high strength and good plasticity.
3. Classification according to the properties and uses of magnesium alloys:
It can be divided into creep resistant magnesium alloy, magnesium alloy mould, wear-resistant magnesium alloy, anti-corrosion magnesium alloy and structural magnesium alloy.
Processing of magnesium alloy parts
Precautions for magnesium alloy processing surface treatment:
Because of its small density and high strength, magnesium alloy is known as a green metal material, which can withstand impact load more than aluminum alloy, and is widely used in the field of automobile parts processing. However, the high temperature performance and corrosion resistance of magnesium alloys are poor, which requires some surface modification or layer treatment to improve the performance of magnesium alloys. The surface treatment of magnesium alloy mainly includes the following methods:
1. Magnesium alloy pretreatment:
Remove the oil stain, rust and other foreign matters attached to the surface of magnesium alloy to obtain a bottom layer that can isolate the environment. Common treatment methods include mechanical cleaning and chemical cleaning.
2. Magnesium alloy electroplating/electroless plating:
Protect magnesium alloy matrix and improve conductivity, wear resistance, corrosion resistance and oxidation resistance of magnesium alloy
Processing of magnesium alloy parts
3. Magnesium alloy conversion coating treatment:
Stable insoluble compound film is formed on the surface of magnesium alloy
①. Chemical conversion of magnesium alloy: simple operation and low cost, but the protective film formed is brittle and porous, and cannot be used as a long-term anti-corrosion protective film of magnesium alloy.
②. Magnesium alloy anodic micro arc oxidation: anodic oxidation uses electrolysis to form oxide film on the surface of magnesium alloy; Micro arc oxidation breaks through the anodic oxidation technology, which has both the performance of anodic oxide film and the advantages of ceramic coating. However, the technology is not mature enough and needs further research.
③. Magnesium alloy E coating: by this method, the magnesium alloy surface can obtain good corrosion resistance
4. Magnesium alloy coating:
① Thermal spraying of magnesium alloy: the spraying materials are heated and melted through flame, laser, arc or plasma and other heat sources, and the surface of magnesium alloy is sprayed at a certain speed to form a protective layer.
② Organic coating and powder coating of magnesium alloy: the organic layer is thin and easy to fall off; Powder coating is difficult to obtain for some concealed coatings.
③. Vapor Deposition of Magnesium Alloys: Improving Corrosion Resistance of Magnesium Alloys
5. Surface modification of magnesium alloy:
It is divided into magnesium alloy diffusion and magnesium alloy ion implantation
6. High energy beam treatment of magnesium alloy:
The surface of magnesium alloy is rapidly heated by laser, plasma, etc. to obtain the surface layer of quenching, rapid solidification or cladding.