Aluminum scandium alloy and preparation method thereof

Abstract

The invention discloses an aluminum-scandium alloy and a preparation method thereof. The method comprises: (1) drying and mixing the halides, heating, melting and heat preservation, and then cooling to obtain block mixed molten salt; (2) heating and melting the aluminum ingot Finally, add the block-shaped mixed molten salt, continue heating until the molten salt is completely melted, then add scandium-containing compounds in batches, and add the block-shaped mixed molten salt in batches to obtain an aluminum-scandium alloy through a reduction reaction. . The method adopts the two-step method of molten salt preparation and thermal reduction reaction to prepare aluminum-scandium alloy, which is simple and quick, with adjustable molten salt composition, controllable scandium content, uniform composition structure of aluminum-scandium alloy, stable scandium content, and small component segregation.

Description

technical field [0001] The invention belongs to the technical field of high-performance aluminum alloy materials, in particular, the invention relates to an aluminum-scandium alloy and a preparation method thereof. Background technique [0002] The addition of scandium to aluminum alloy can significantly refine the grain structure of the alloy and increase the recrystallization temperature, thereby improving the corrosion resistance, heat resistance, weldability and neutron radiation damage resistance of the aluminum alloy. Due to the excellent characteristics of light weight, high strength, good plasticity, high temperature resistance, corrosion resistance and good weldability, aluminum-scandium alloy can be widely used in aerospace, automobile, rail transit as an advanced high-performance lightweight structural material , military science and defense and other fields. [0003] At present, the preparation of aluminum-scandium alloy mainly includes pair mixing method, therm...

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Problems solved by technology

The thermal reduction method includes: after mixing the molten salt according to a certain proportion, adding it to the molten pure aluminum melt, and then reducing reaction at a certain temperature to obtain an aluminum-scandium master alloy. Since the mixed molten salt powder is doped with a large amount of gas, Adding molten aluminum into the molten aluminum is very easy to cause oxidation and burning loss, resulting in a change in the composition of the mixed molten salt, affecting the next step of the aluminothermic reduction reaction, making it difficult to control the composition of the aluminum-scandium master alloy; some fluorinating agents are NH 4 HF 2 It is highly irritating and toxic, and long-term exposure will cause harm to the body and serious environmental pollution, so it is not conducive to industrial production; some use scandium fluoride and aluminum as raw materials to prepare aluminum scandium alloys by thermal reduction method, the disadvantage is the reduction reaction It needs to be carried out in a vacuum reactor, which requires a high temperature of 1100-1350 ° C, which significantly increases the production cost. In addition, the high vacuum and high temperature environment have high requirements for reduction equipment, and it is difficult to realize industrial application.

It can be seen that the current electrolytic method has complicated devices and high cost, and the aluminum-scandium alloy produced by the thermal reduction method faces the problem of uneven structure and composition.

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