Analysis of elemental composition of spheroidizer

What are the elements in the spheroidizer? Mg, Re, Ca, Si, Al, and so on. What are the other rare elements? In Mg alloys, the beneficial effect of rare earth on non-ferrous metals is obvious. It not only constitutes the Si-Mg alloy system but also has a significant influence on the Mg-Al and Mg-Zn alloy systems. The following by Anyang Jinsheng Metallurgy for your detailed introduction of the main role of spheroidizing agent;

1. Grain refinement: Appropriate rare earth content can refine the grain of magnesium and magnesium alloy. The first is to refine the particles of the matrix. The thinning mechanism of rare earth elements is not the result of a heterocyclic nucleus. The effect of rare earth elements on the grain refinement of magnesium and its alloys is due to the increase of the degree of supercooling in the crystallization front. The second is to prevent recrystallization and grain growth in the process of heat treatment and annealing.

2. Purification melt: the affinity between rare earth elements and oxygen is greater than that between magnesium and oxygen, so rare earth elements can react with oxides such as MgO in the melt to form rare earth oxides and precipitate to remove oxide inclusions. It reacts with hydrogen and water vapor in the melt to form cyanide or rare earth oxides to deoxidize. At the same time, increase the melt fluidity, reduce the shrinkage of the casting, improve the density of the casting.

3. With the increase of the strength of the alloy at room temperature, the solid solubility of most rare earth elements in magnesium is greater, and the solid solubility changes obviously with the decrease of temperature. Therefore, in addition to solution strengthening, rare earth elements are also effective aging strengthening elements in magnesium alloys.

4. Improve the corrosion resistance of the alloy: by purifying the melt, the harmful effects of impurities (such as iron) are reduced and the corrosion resistance is improved. To improve the thermal stability of mechanical properties of the alloy. The spheroidizing agent manufacturers believe that rare earth elements are effective alloying elements to improve the heat resistance of rare earth and magnesium spheroidizing agent and magnesium alloy, and can significantly improve the high-temperature strength and creep properties of magnesium alloy. The rare earth magnesium with a low diffusion coefficient can slow down the recrystallization process and increase the recrystallization temperature, increase the aging effect of desilting and the thermal stability stage, and the main grain boundary of the rare earth compounds with the high melting point, block the dislocation movement and improve the creep resistance at high temperature.