The oxide film of Al-Mg alloy is easy to form, the quality of the film is also better, and it can be oxidized and colored, which is an important feature different from other alloys. But compared with deformed aluminum alloy, there are some disadvantages.
1, the anodic oxide film has a dual nature, and the pores are large, uneven distribution, it is difficult to achieve better anti-corrosion effect;
2, magnesium has hardening and brittleness, reduce elongation, increase the tendency of hot cracking, such as ADC5, ADC6, etc., in the production, because of its wide solidification range, shrinkage tendency is large, often produce shrinkage and cracking, casting performance is very poor, therefore, there are greater limitations in its scope of use, slightly complex structure of the workpiece, simply not suitable for production;
3, the commonly used aluminum magnesium alloy on the market, because of its complex composition, aluminum purity is too low, sulfuric acid anodizing, it is difficult to produce transparent protective film, mostly milky white, the color state is poor, according to the normal process is difficult to achieve the ideal effect.
