A process for preparing aluminum alloy semi-solid blanks by combining electromagnetic forming and secondary remelting

Abstract

The invention discloses a process for preparing a semisolid aluminum alloy blank by compounding electromagnetic molding and secondary remelting. The process comprises the following steps of selecting an aluminum alloy bar material; carrying out plastic deformation on the aluminum alloy bar material by using an electromagnetic molding device, and enabling the aluminum alloy bar material to generate plastic strain; and next, pushing the metal bar material generating plastic strain into a medium-frequency induction heating device to carry out secondary remelting treatment to prepare the semisolid aluminum alloy blank with a fine and uniform approximately-spherical non-dendritic microstructure. The process has the characteristics of simple technological process, low cost, high efficiency, excellent molding performance and the like.

Description

technical field [0001] The invention belongs to the technical field of metal semi-solid blank preparation, and in particular relates to a process for preparing an aluminum alloy semi-solid blank by combining electromagnetic forming and secondary remelting. Background technique [0002] Semi-solid processing is a metal forming method proposed by Professor Flemings of the Massachusetts Institute of Technology in the 1970s. The so-called semi-solid processing is to heat the metal to the temperature between the solidus line and the liquidus line, and keep it warm for a certain period of time to obtain spherical or nearly spherical grains, and then shape them. Spherical or nearly spherical The semi-solid slurry has the advantages of good fluidity, low forming force and good performance of the formed parts, so this process has received more and more attention. [0003] In the semi-solid forming process, how to obtain a semi-solid slurry with a non-dendritic fine and uniform near-...

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Problems solved by technology

At present, in the preparation of non-ferrous metal semi-solid slurry, the electromagnetic stirring method is the most widely used, and has been used in industrial production, but there are also disadvantages: ① The melting point of ferrous metals is high and the conductivity of the melt is low, so that the semi-solid slurry The preparation brings great difficulties, such as the required large stirring power and long stirring time; ②Due to the skin effect, the Lorent magnetic force in the semi-solid slurry gradually increases from the center to the periphery, so billets with a diameter greater than 150mm are not suitable for use Electromagnetic stirring method, and the blank structure is not uniform on the cross section; ③ During the preparation of semi-solid slurry by electromagnetic stirring method, an alternating magnetic field is generated, so the power consumption is large and the cost is high, and when the solidified shell is formed around the molten metal , the mixing effect is not good

The key technology of the strain-induced melting activation method (SIMA) is how to plastically deform the conventional cast ingot. Currently, the commonly used method is to plastically deform the cast ingot, such as upsetting, extrusion or rolling, but there are The problem of small deformation and low deformation efficiency, therefore, the current preparation technology of spherical or granular primary crystal semi-solid metal slurry or continuous casting billet still restricts the application of semi-solid metal forming technology

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