Extruding method for texture-weakened magnesium alloy sheet

Abstract

A disclosed extruding method for a texture-weakened magnesium alloy sheet comprises: 1) getting at least two heterogenous magnesium alloy blocks or magnesium alloy and aluminium alloy, superposing and fixing; 2) putting the superposed magnesium alloy block or the magnesium-alloy aluminium-alloy block obtained in the step 1) into an extrusion cylinder for extruding, and enabling the alloy block to be synchronously extruded from the extrusion die orifice, so as to obtain a magnesium-magnesium or magnesium-aluminium composite sheet; and 3) removing the aluminium layer or the relatively-thin magnesium layer on the composite sheet, so as to obtain the texture-weakened magnesium alloy sheet, wherein the magnesium alloy is preferably AZ31, AZ61 and AZ80 wrought magnesium alloy, and aluminium alloy is preferably 5052 and 6063. Thickness-direction metal mixing does not happen in the magnesium alloy sheet or the magnesium-alloy aluminium-alloy sheet during extrusion, also the two sides of the sheet when being extruded possesses a relatively large flow velocity difference, thus shear stress is introduced into the same magnesium alloy block, and the effects of refining crystal grain and weakening texture are given play. By employing the method of firstly performing combination and extrusion and then peeling off the relatively-thin magnesium layer, the crystal grain is obviously refined, and the texture is weakened.

Description

technical field [0001] The invention belongs to the field of magnesium alloys and relates to a magnesium alloy forming method, in particular to a method for producing high-strength and low-texture magnesium alloy plates through a composite extrusion forming method. Background technique [0002] Magnesium alloy has the advantages of high specific strength and specific stiffness, good thermal conductivity and damping performance, excellent electromagnetic shielding performance and machining performance, and has a wide range of application values ​​in various fields such as aerospace, automobiles, electrical appliances, and communications. Since the crystal structure of magnesium alloy is hexagonal close-packed and lacks an independent slip system, processing is difficult. So far, most magnesium alloy products are mainly produced by casting, but casting products have shortcomings such as coarse structure and many defects, which lead to unsatisfactory mechanical properties, whic...

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Problems solved by technology

Although these two methods both add magnesium and aluminum to the extruder simultaneously for extrusion, the main purpose is to form an aluminum alloy protective layer on the surface of the magnesium alloy, thereby improving its corrosion resistance, and the magnesium alloy is completely in the two methods. Coated by aluminum alloy, the lateral flow of the magnesium alloy extruded sheet is restricted by the clad aluminum during the extrusion process, and it is easy to produce uneven lateral distribution, which eventually leads to uneven lateral structure and properties of the entire composite material, and serious anisotropy , can not meet the requirements of use; in addition, the magnesium alloy is not in contact with the extrusion cylinder during the extrusion process of this method, and it is in a state of symmetrical stress along the thickness direction (the deformation process of the magnesium alloy is similar to the symmetrical extrusion of ordinary magnesium alloys , can not improve the basal texture of magnesium alloy)

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