What are the elements in the spheroidizing agent? There are Mg, Re, Ca, Si, Al, etc. What are the rare elements? In magnesium alloys, the beneficial effects of rare earths on non-ferrous metals are obvious. It not only constitutes the silicon-magnesium alloy system, but also has a significant impact on all Mg-Al and Mg-Zn. The following is what Fang Yuan Xiaobian shared for everyone, let's look down together.
1. Refine the grain
Proper rare earth content can optimize magnesium and magnesium alloy particles. The first is the particles of the substrate. The mechanism by which rare earth elements refine the matrix of magnesium alloys is not the result of heterocyclic cores. The effect of rare earth elements on the grain refinement of magnesium and its alloys is due to the increase in the degree of overfrequency along the crystallization. The second is to prevent recrystallization and grain growth during heat treatment and annealing.
2. Purify the melt
Rare earth elements and oxygen have an affinity that is higher than that of magnesium and oxygen, so the rare earth elements can react with oxides in the melt, such as MgO, to form rare earth oxides, which are precipitated to remove oxide inclusions. It reacts with molten hydrogen and water vapor to form cyanide or rare earth oxide to deoxidize. At the same time, it increases the fluidity of the melt, reduces the shrinkage of the casting, and increases the density of the casting.
3. Improve the alloy strength at room temperature
Most magnesium has high solid solubility, and temperature solubility varies with temperature. Therefore, in addition to the solid solubility in magnesium alloys, rare earth elements are also an effective aging strengthening element.
4. Improve the corrosion resistance of the alloy
By purifying the melt, the harmful effects of impurities (such as iron) are reduced, and corrosion resistance is improved. Improve the thermal stability of the alloy's mechanical properties.
The editor believes that the spheroidizing agent is an effective alloying element that can improve the heat resistance of rare earth magnesium textiles and magnesium alloys, which can significantly improve the high-temperature strength and creep properties of magnesium alloys. The small diffusion coefficient of rare earth magnesium can reduce the recrystallization process and increase the recrystallization temperature, increase the dredging aging effect and thermal stability, and the main grain boundary of the high melting point rare earth compound prevents dislocation and improves the temperature creep resistance. This is the end of the sharing, let’s see you next time~~