阅读说明：本技术 一种制备Al-Cu-Mg合金纳米晶粒组织的装置和方法 (Device and method for preparing Al-Cu-Mg alloy nanocrystalline grain structure ) 是由 范语楠 范才河 阳建君 欧玲 严红革 何世文 郑东升 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种制备Al-Cu-Mg合金纳米晶粒组织的装置和方法,包括多道次再结晶退火步骤和多道次高速剪切处理步骤,所述再结晶退火的温度为750～800K,保温时间为20～40min；所述Al-Cu-Mg合金两侧分别设置有用于对合金进行高速剪切处理的剪切板一和剪切板二,所述高速剪切处理步骤中,剪切板一和剪切板二与合金表面紧密贴合并沿合金表面高速上下移动对合金进行剪切,使合金产生剧烈形变,所述剪切板一和剪切板二的移动方向相反。本发通过剧烈剪切变形和再结晶退火工艺相结合细化Al-Cu-Mg合金晶粒组织,以提高合金的综合力学性能。(The invention discloses a device and a method for preparing an Al-Cu-Mg alloy nanocrystalline grain structure, which comprises a multi-pass recrystallization annealing step and a multi-pass high-speed shearing treatment step, wherein the recrystallization annealing temperature is 750-800K, and the heat preservation time is 20-40 min; the alloy shearing device comprises an Al-Cu-Mg alloy and is characterized in that a first shearing plate and a second shearing plate which are used for carrying out high-speed shearing treatment on the alloy are respectively arranged on two sides of the Al-Cu-Mg alloy, in the step of high-speed shearing treatment, the first shearing plate and the second shearing plate are closely attached to the surface of the alloy and move up and down along the surface of the alloy at a high speed to shear the alloy, so that the alloy is severely deformed, and the moving directions of the first shearing plate and the second shearing plate are opposite. The Al-Cu-Mg alloy grain structure is refined by combining the severe shear deformation and the recrystallization annealing process, so that the comprehensive mechanical property of the alloy is improved.)

1. The device for preparing the Al-Cu-Mg alloy nanocrystalline grain structure is characterized by comprising a shear plate I, a shear plate II and a driving motor, wherein the shear plate I and the shear plate II are connected with the driving motor through a mechanical arm and used for controlling the shear rate; the first shearing plate and the second shearing plate are arranged on two sides of the Al-Cu-Mg alloy.

2. A method for preparing Al-Cu-Mg alloy nanocrystalline grain structure by using the device of claim 1 is characterized by comprising a multi-pass recrystallization annealing step and a multi-pass high-speed shearing treatment step, wherein the temperature of recrystallization annealing is 750-800K, and the holding time is 20-40 min; the alloy shearing device comprises an Al-Cu-Mg alloy and is characterized in that a first shearing plate and a second shearing plate which are used for carrying out high-speed shearing treatment on the alloy are respectively arranged on two sides of the Al-Cu-Mg alloy, in the step of high-speed shearing treatment, the first shearing plate and the second shearing plate are closely attached to the surface of the alloy and move up and down along the surface of the alloy at a high speed to shear the alloy, so that the alloy is severely deformed, and the moving directions of the first shearing plate and the second shearing plate are opposite.

3. The method for preparing an Al-Cu-Mg alloy nanocrystalline grain structure according to claim 2, characterized in that the shear rate of the shear plate is 70-100 mm/s.

4. The method for preparing an Al-Cu-Mg alloy nanocrystalline grain structure according to claim 3, characterized in that the temperature rise rate of the recrystallization annealing step is 620 to 650K/min.

5. A method of producing an Al-Cu-Mg alloy nanocrystalline grain structure according to any one of claims 2 to 4, characterized by comprising a four-pass high shear treatment step and a four-pass recrystallization annealing step.

6. The method for preparing an Al-Cu-Mg alloy nanocrystalline grain structure according to claim 5, characterized in that the high-speed shearing treatment step and the recrystallization annealing step are performed alternately, the first process is a first-pass recrystallization annealing, the second process is a first-pass high-speed shearing treatment, the third process is a second-pass recrystallization annealing, the fourth process is a second-pass high-speed shearing treatment, the fifth process is a third-pass recrystallization annealing, the sixth process is a third-pass high-speed shearing treatment, the seventh process is a fourth-pass recrystallization annealing, and the eighth process is a fourth-pass high-speed shearing treatment.

7. The method for preparing an Al-Cu-Mg alloy nanocrystalline grain structure according to claim 5, wherein the shear rate of the shear plate in the first-pass high-speed shearing treatment step is 95-100 mm/s, and the shear rate of the shear plate in the second-pass high-speed shearing treatment step is 90-95 mm/s.

8. The method for preparing an Al-Cu-Mg alloy nanocrystalline grain structure according to claim 5, wherein the shear rate of the shear plate in the third high-speed shearing treatment step is 75-90 mm/s, and the shear rate of the shear plate in the fourth high-speed shearing treatment step is 70-75 mm/.

9. The method for preparing the Al-Cu-Mg alloy nanocrystalline grain structure according to claim 2, characterized in that the recrystallization annealing temperature is 760-780K, and the holding time is 30 min.

10. The method of producing an Al-Cu-Mg alloy nanocrystalline grain structure according to claim 2, characterized in that the Al-Cu-Mg alloy has the composition: cu: 4-6 wt.%, Mg: 1-3 wt.%, Mn: 0.2-1.2 wt.%, Si: 0-0.05 wt.%, Fe: 0 to 0.05 wt.%, and the balance of Al.

Technical Field

The invention relates to the technical field of metal material processing, in particular to a device and a method for preparing an Al-Cu-Mg alloy nano grain structure.

Background

Al-Cu-Mg alloy has been widely used in aerospace and military fields because of its high strength, good formability and heat resistance. However, the Al-Cu-Mg alloy prepared by the conventional technology still cannot meet the application requirements in the military industry. The long flaky nano precipitated phase S' phase is a main strengthening phase in the Al-Cu-Mg alloy with low Cu/Mg ratio, the precipitation strengthening is a main strengthening mode of the Al-Cu-Mg alloy, and the refined grains are a main strengthening and toughening way of the alloy.

During large deformation of the high-stacking fault energy aluminum alloy polycrystal, due to different crystallographic orientations of crystal grains adjacent to a grain boundary, deformation of each crystal grain must be coordinated with adjacent crystal grains so as to maintain the continuity of deformation of the polycrystal. During severe deformation of an aluminum alloy, regions of different orientations, i.e., deformation bands, are separated in coarser grains due to uneven stress of the grains propagating to adjacent grains or instability of the grains during plastic deformation. The mechanism of transition zone transformation deformation induced grain boundary in the deformation process can effectively refine coarse grains and large grains in the alloy and plays an important role in obtaining uniform fine grain structures.

The existing research mainly discusses the microstructure evolution and mechanical property characteristics of Al-Cu-Mg alloy under the conditions of conventional deformation and aging temperature, and no report that high-speed shearing and recrystallization annealing process is applied to the preparation of nano-grain structure of Al-Cu-Mg alloy exists at present.

Disclosure of Invention

The invention aims to provide a device and a method for preparing Al-Cu-Mg alloy nano-grain structure aiming at the defects in the prior art, and the nano-grain structure is promoted to be formed in the Al-Cu-Mg alloy through the combination of high-speed shearing and recrystallization annealing processes, so that grains are effectively refined, and the mechanical property of the alloy is improved.

The purpose of the invention is realized by the following technical scheme:

a device for preparing an Al-Cu-Mg alloy nanocrystalline grain structure comprises a shear plate I, a shear plate II and a driving motor, wherein the shear plate I and the shear plate II are connected with the driving motor through a mechanical arm and are used for controlling the shearing rate; the first shearing plate and the second shearing plate are arranged on two sides of the Al-Cu-Mg alloy.

A method for preparing an Al-Cu-Mg alloy nanocrystalline grain structure by using the device comprises a multi-pass recrystallization annealing step and a multi-pass high-speed shearing treatment step, wherein the temperature of recrystallization annealing is 750-800K, and the heat preservation time is 20-40 min; the alloy shearing device comprises an Al-Cu-Mg alloy and is characterized in that a first shearing plate and a second shearing plate which are used for carrying out high-speed shearing treatment on the alloy are respectively arranged on two sides of the Al-Cu-Mg alloy, in the step of high-speed shearing treatment, the first shearing plate and the second shearing plate are closely attached to the surface of the alloy and move up and down along the surface of the alloy at a high speed to shear the alloy, so that the alloy is severely deformed, and the moving directions of the first shearing plate and the second shearing plate are opposite.

Based on the microstructure characteristics of the Al-Cu-Mg alloy, the uniform nanocrystalline structure is obtained through repeated dislocation multiplication and continuous recrystallization by the alternate action of high-speed shear deformation and recrystallization annealing, so that the mechanical property of the alloy is improved.

Further, the shear plate is connected with a driving motor for controlling the shear rate.

Further, the shear rate of the shear plate is 70-100 mm/s.

Further, the temperature rise rate of the recrystallization annealing step is 620-650K/min.

According to the invention, rapid heating is adopted in the recrystallization annealing step, desolventizing particles in the alloy are avoided, the recrystallization temperature is effectively reduced, and the recrystallization is promoted, so that a precipitated phase which is formed in the subsequent recrystallization annealing process and is enough to influence the recrystallization is carried out in recrystallized grains, and the uniformity and refinement of the alloy grain structure are promoted.

Further, the method for preparing the nanocrystalline grain structure comprises a four-pass high-speed shearing treatment step and a four-pass recrystallization annealing step.

Further, the high-speed shearing treatment step and the recrystallization annealing step are alternately performed, the first process is first-pass recrystallization annealing, the second process is first-pass high-speed shearing treatment, the third process is second-pass recrystallization annealing, the fourth process is second-pass high-speed shearing treatment, the fifth process is third-pass recrystallization annealing, the sixth process is third-pass high-speed shearing treatment, the seventh process is fourth-pass recrystallization annealing, and the eighth process is fourth-pass high-speed shearing treatment.

Further, the shearing rate of the shearing plate in the first-pass high-speed shearing treatment step is 95-100 mm/s.

Further, the shearing rate of the shearing plate in the second-pass high-speed shearing treatment step is 90-95 mm/s.

Further, the shearing rate of the shearing plate in the third high-speed shearing treatment step is 75-90 mm/s.

Further, the shearing rate of the shearing plate in the fourth-pass high-speed shearing treatment step is 70-75 mm/s.

Further, the temperature of recrystallization annealing is 760-780K, and the heat preservation time is 30 min.

Further, the Al-Cu-Mg alloy comprises the following components: cu: 4-6 wt.%, Mg: 1-3 wt.%, Mn: 0.2-1.2 wt.%, Si: 0-0.05 wt.%, Fe: 0 to 0.05 wt.%, and the balance of Al.

Compared with the prior art, the invention has the following beneficial effects:

the invention creatively carries out high-speed shearing and recrystallization annealing treatment on the Al-Cu-Mg alloy, scientifically designs a high-speed shearing process, and continuously increases the deformation in the alloy along with the increase of high-speed shearing passes, the recrystallization degree is larger and larger, the grain size is thinner and finer, and the grain structure is more uniform. Under the alternate action of high-speed shearing and recrystallization annealing, the interior of the alloy is subjected to repeated dislocation multiplication and continuous recrystallization to form a microstructure mainly composed of large-angle grain boundaries, and compared with an alloy sample subjected to conventional deformation, the grains are obviously refined.

The invention provides a novel method for preparing a nano-crystalline grain structure, which improves the mechanical property of the alloy through fine-grain strengthening. In the high-speed shearing process, a large amount of cell structures or sub-crystals are formed and are used as recrystallization cores in the recrystallization annealing step to remarkably promote the recrystallization, so that the crystal grains are effectively refined, the grain boundary area is increased, and the strength and the toughness of the alloy are improved.

Drawings

FIG. 1 is a schematic diagram of a high shear processing step;

wherein 1 is Al-Cu-Mg alloy, 2 is a shear plate I, 3 is a shear plate II, and 4 is a driving motor;

FIG. 2 is a schematic view of high-speed shearing and recrystallization annealing treatment of the Al-Cu-Mg alloy in example 1;

FIG. 3 is a TEM image of the grain morphology of the Al-Cu-Mg alloy after 2-pass high-speed shearing and recrystallization annealing treatment in the present invention;

FIG. 4 is a TEM image of the crystal grain morphology of the Al-Cu-Mg alloy after 4-pass high-speed shearing and recrystallization annealing treatment in the invention.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following specific examples.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.