A kind of reciprocating reverse extrusion processing method of reinforced magnesium alloy pipe

Abstract

The invention relates to performance enhancement of magnesium alloy pipes and improvement of processing methods, in particular to a cyclic reverse extrusion compression processing method for reinforcing a magnesium alloy pipe. According to the novel cyclic reverse extrusion compression processing method, cyclic reverse extrusion compression is conducted on the magnesium alloy pipe inside a mould cavity on a vertical type hydraulic extruder in the heated state; in the cyclic reverse extrusion compression process, the wall thickness of the magnesium alloy pipe maintains unchanged, uniform-section corner deformation occurs, and the pipe flows in the reverse direction; the inner diameter and the outer diameter change, and severe plastic deformation of the magnesium alloy pipe is achieved through accumulative deformation; and the grain structure is refined and densified so that performance of the magnesium alloy pipe can be enhanced. By means of the method, the application field and the application scope of the magnesium alloy pipe are widened.

Description

technical field [0001] The invention relates to performance enhancement of magnesium alloy pipes and improvement of processing methods, in particular to a reciprocating reverse extrusion processing method of reinforced magnesium alloy pipes, and belongs to the technical field of plastic processing of non-ferrous metals and enhancement of mechanical properties. Background technique [0002] Magnesium alloy is currently the lightest metal structure material available, the density of pure magnesium is 1.74g / cm 3 , about 2 / 3 of aluminum alloy and 1 / 4 of steel. Magnesium alloys have great application prospects in aerospace, national defense, transportation, machinery, electronics and other industrial fields due to their significant effects in energy saving, emission reduction, and weight reduction. However, magnesium alloys have a close-packed hexagonal structure and few independent slip systems, which lead to relatively low strength and poor room temperature plasticity, so the ...

AI Technical Summary

Problems solved by technology

These severe plastic deformation technologies have their own characteristics. For example, reciprocating extrusion can prepare large-volume ultrafine grain materials with uniform structure, but most of the current reciprocating extrusion technologies can only prepare bulk materials, and their application range is limited; Compression is one of the effective ways to refine grains. During extrusion, the shape and size of the sample remain unchanged. Repeated extrusion can accumulate large deformations. However, one extrusion can only obtain a deformation with a maximum strain of about 1. , the amount of single extrusion deformation is small; cumulative rolling can also refine the grain structure of the material, but it will lead to a decrease in the plasticity of the material; high-pressure torsion can prepare materials with nanocrystalline structures, but the prepared sample structures are not Homogeneous, and can only be used to prepare thin sheet samples and limited in size

In short, these severe plastic deformation methods have many technical defects and drawbacks.

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