What harm does the smoke produced by aluminum castings have to human body?

According to the report of American patent. No.6,929,70682, Corus Aluminium and Corus Muminium Walzproclukte GmbH in Wilde, Germany invented a die-casting aluminum alloy, which has good die-casting performance and high comprehensive mechanical properties, and can be used for die-casting various parts with complex shapes. Its composition (mass percentage): magnesium 4.5 ~ 6.0, manganese 0.4 ~ 1.4, zinc 0. 10 ~ 0.9. Zr 0.05 ~ 0.25，V 0.3 max，Sc0.3max，Ti0.2max，Fe 1.0max，Si 66。

Influence of additives and impurities in die casting aluminum alloy.

(1) the role of silicon and magnesium

The specific gravity and linear expansion coefficient of Si are smaller than that of Al, and both are face-centered cubic crystals. Adding Si into the alloy can improve the casting performance, fluidity, shrinkage and hot cracking tendency, reduce porosity, shrinkage, hot cracking and deformation, and improve air tightness. The role of Mg is to improve its strength and toughness; As-cast, except for a small amount of Mg, it mainly exists in the form of larger Mg2Si phase, so the effect of Mg on the as-cast mechanical properties of the alloy is not obvious. The strength of the alloy increases with the increase of Si content and slightly with the increase of Mg content, but the elongation decreases obviously with the increase of Si and Mg content.

(2) the harmful effects of iron

Among the impurity elements, iron is the most harmful to casting Al-Si alloy. It is easy to form brittle intermetallic compounds with Al, which seriously reduces the toughness of materials. Fe mainly exists in the form of α and β intermetallic compounds in 4004 alloy. With the increase of Fe content, β phase transformation becomes coarse and needle-like. Because the solid solubility of Fe in α-Al is very small, during the solidification process, with the growth of Al, Fe is enriched at the dendrite front, forming a micro-enriched area of Fe. Therefore, even if the Fe content in the alloy is extremely low, an Fe-rich phase can be formed in the alloy. Among them, β phase (FeSiAl5, Al9Fe2Si2) has the most serious influence on the mechanical properties of the alloy. With the precipitation of β phase in coarse flake form, plasticity, impact toughness and fracture toughness will decrease. The Chinese character-like α has little effect on the fracture of the alloy, but it still has a positive effect on the fracture of the alloy, which reduces the mechanical properties of the alloy.

(3) the role of 3)Mn

After manganese is added to the alloy, the coarse needle-like β(Al9Fe2Si2) phase in the microstructure can be transformed into small-sized massive AlSiMnFe compounds, thus greatly reducing the harmful effects of Fe on the properties of the alloy.