A method for synergistic hypoeutectic casting Al-Si alloy modification and microalloying

Abstract

A synergistic method for metamorphism and microalloying of a hypoeutectic casting Al-Si alloy comprises: melting the hypoeutectic casting Al-Si alloy, adding a refining agent thereto for degassing and slag removal, adding rare earth elemental La, settling and maintaining at a certain temperature, further adding elemental Mg, settling and maintaining at a certain temperature, and finally casting at a certain temperature. By means of the metamorphizing action of La and Mg and the mutual promotion of metamorphism of these two elements, favorable metamorphism of the Al-Si alloy can be achieved. At the same time, La and Mg as microalloying elements can strengthen the Al-Si alloy, improving alloy performance. In addition, for an Al alloy melt, the method includes dehydrogenation and degassing, reducing oxide inclusion, and purifying the melt, thereby improving the alloy structure and enhancing the mechanical performance thereof.

Description

technical field [0001] The invention belongs to the technical field of aluminum alloys, and in particular relates to a method for modifying and microalloying a hypoeutectic cast aluminum-silicon alloy. [0002] technical background [0003] Hypoeutectic cast aluminum-silicon alloy has low density, high specific strength, and is easy to form. It is suitable for the production of various complex-shaped and high-performance structural parts, and is widely used in various industries such as aviation, aerospace, automobiles, and machinery. However, in the as-cast alloy, the eutectic silicon presents a coarse needle-like or slab-like shape without modification. This form of silicon will split the alloy matrix and greatly reduce the strength and plasticity of the aluminum-silicon alloy. At present, in industrial production, the method of modification treatment is generally adopted to eliminate the adverse effects of coarse needle-like or plate-like silicon phases. Modification trea...

AI Technical Summary

Problems solved by technology

Although Na modification has a good modification effect, it is prone to decay and failure, and it is easy to generate smog to pollute the environment during the addition process; although Sr modification has the advantages of obvious modification effect and long-term effect, it has a long latent period of modification, serious inhalation tendency, and serious burning loss. , the tissue is prone to defects such as pores and shrinkage porosity; Sb deterioration has the advantages of no decay and small air absorption tendency, but the effect of Sb deterioration is general, and Sb is toxic, and toxic gases will be generated during smelting and pouring. approved for use under the conditions

[0005] The aluminum-silicon alloys used in engineering applications are all multi-element alloys, that is, it is necessary to introduce a certain amount of elements La and Mg in advance for microalloying, and then undergo modification treatment. The smelting process is relatively cumbersome

Images