Short-process severe plastic deformation preparation method of large-specification rare earth magnesium alloy high-performance ingot blank

Abstract

When the short-process severe plastic deformation preparation method is used, an ejection cylinder moves upwards, the height of a back pressure plate is adjusted to an outlet of an extrusion deformation zone, firstly, a press machine drives a male die to move downwards, and a cylindrical blank is gradually extruded into the extrusion deformation zone; the bottom of the blank slowly deforms and shrinks, an extrusion deformation zone is filled, the bottom of the blank continuously moves downwards along with the male die, the bottom of the blank makes contact with the upper surface of the back pressure plate, and when the contact width is close to the size of an extrusion forming piece, the back pressure plate starts to return downwards along with the male die; after the stroke of the male die is finished, the recoverable residual pressing block is filled in the extrusion deformation zone, and upset-extrusion deformation is finished; and then the ejection cylinder drives the back pressure plate to downwards retreat from the lower part of the lower cavity, so that the residual pressure block can be recovered to be broken under the action of high pressure, and then the extruded blank and residual pressure block powder are taken out from the lower part of the lower cavity and are recovered into a plate shape for next use. The tail shrinkage phenomenon can be solved, materials are saved, and the strengthening effect is improved.

Description

technical field [0001] The invention belongs to the technical field of metal plastic processing, and in particular relates to a method for preparing a large-scale rare earth magnesium alloy high-performance ingot by short-flow drastic plastic deformation. Background technique [0002] like figure 1 As shown in the figure, in the metal plastic deformation mold, traditional positive extrusion is the most basic extrusion method. Because of its high three-dimensional compressive stress intensity, it can fully improve the plastic deformation ability of metal materials, and has the advantages of simple process operation and large production flexibility. Features, widely used. But there are still the following shortcomings: (1) The metal flow is uneven during extrusion, the middle flow is fast, and the edge flow is slow, such as figure 2 In the middle, there is a shrinkage, which is not conducive to continuous extrusion; (2) there is a conical deformation zone in the extrusion d...

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Problems solved by technology

But there are still the following disadvantages, (1) The metal flow is not uniform during extrusion, the middle flow is fast, and the edge flow is slow, such as figure 2 The shrinkage shown in A in the middle is not conducive to continuous extrusion; (2) There is a conical deformation zone in the extrusion die, so that there is still excess pressure after the extrusion is completed; the existence of excess pressure and shrinkage makes the extrusion It is necessary to cut the head and tail, resulting in material waste; (3) The preparation of existing large-scale magnesium alloys mostly adopts the "multiple heating and repeated extrusion-upsetting" process, that is: 1) heating homogenization-2) heating-3) Extrusion-4) head and tail removal-5) heating-6) upsetting, repeat 2)-6) three times, a total of 16 processes, the cumulative total strain is 3-4 larger, and has a certain strengthening and toughening effect

However, the gap between each upsetting cycle of this process needs to be reheated. In addition to high energy consumption, each heating will weaken the strengthening effect, which greatly reduces the strengthening effect; in addition, the gap between each upsetting cycle needs to be reheated Cutting is performed on excess pressure, long working hours, low material utilization and production efficiency, making the overall cost high and limiting the application of mass production of magnesium alloys

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