Rare earth removal of impurities and on the influence of the inclusions

Distribution in aluminum and its alloy matrix and grain boundary compounds for all kinds of intermetallic compound and the oxide and aluminum oxide. The composition, morphology, distribution and quantity of these compounds on the performance of the aluminum and its alloys, especially the plastic processing and performance has a significant influence. Inclusion of aluminum powder and its alloy owner if Al2O3 etc. Nonmetal inclusion, its existence not only reduce the processing performance and mechanical properties of alloy, and worsen the casting performance. When pure aluminium (as-cast, variable form) after adding 0.2% of rare earth, the distribution of the original intracrystalline bulky blocks disappear, spherical rare earth phase formation, grain boundary strips and fragmental compounds decreased significantly, the point chain compound forming, plastic good uniform organization. And found that after adding 0.2% rare earth alloy, the original is distributed in the intracrystalline glomeration of rough patches, and in the uniform distribution of globular phase is formed on the substrate, while eliminating the boundary brittle fragmental and strip compounds, forming small point chain distribution of plastic compounds, and lined up along the deformation direction. To join before and after the rare earth Alumina Oxide and its alloy matrix, the grain boundary in the compound, intracrystalline bulky compounds and globular compounds such as phase composition were determined. Contrast found that after joining the rare earth, which makes the impurity in the aluminum and its alloys, such as iron and other elements, to high rare-earth poly globular phase, so that the final solidification grain boundary of impurity element is greatly reduced, purify grain boundary, the grain boundary in high-speed rail brittle phase reduction, grain boundary strength increased, the plastic improvement; And grain boundary distribution point chain compounds as low iron, the composition of rare earth phase, is close to the aluminum substrate of plastic compounds, particularly in the rare earth alloy spherical phases partial quantity is relatively pure aluminium cuhk, so its distribution in aluminum alloy grain boundary minimal, so the boundary of aluminum alloy is more thin, more pure than pure aluminium.