阅读说明：本技术 一种镁合金构件的增塑工艺 (Plasticizing process of magnesium alloy component ) 是由 夏祥生 陈强 舒大禹 黄树海 林军 康凤 王艳彬 于 2019-11-22 设计创作，主要内容包括：本发明提供了一种镁合金构件的增塑工艺,步骤包括：热处理过程中,在镁合金构件的组织内引入孪晶缺陷,并对镁合金构件进行时效处理。采用对镁合金构件进行冷压的方式引入孪晶缺陷,冷压过程中的温度控制为10~30℃,冷压后的总变形量控制为3~9%。本发明通过在镁合金构件的组织内引入孪晶缺陷,并对镁合金构件进行时效处理,使得镁合金构件的强度和塑性得到同步提高,解决了传统热处理工艺强度增加但塑性下降的难题；经本发明处理后的镁合金构件抗拉强度可达411-512MPa,断后伸长率可达14-17%,表面粗糙度等级可达IT8-IT10级,为镁合金构件的拓展应用提供了更多的可能；此外,本发明工艺操作简单,易于实施,适合于工业化大规模生产。(The invention provides a plasticizing process of a magnesium alloy component, which comprises the following steps: in the heat treatment process, twin defects are introduced into the structure of the magnesium alloy member, and the magnesium alloy member is subjected to aging treatment. The method for cold pressing the magnesium alloy component is adopted to introduce twin crystal defects, the temperature in the cold pressing process is controlled to be 10-30 ℃, and the total deformation after cold pressing is controlled to be 3-9%. The invention leads the strength and the plasticity of the magnesium alloy component to be synchronously improved by introducing twin crystal defects into the structure of the magnesium alloy component and carrying out aging treatment on the magnesium alloy component, thereby solving the problem that the strength is increased but the plasticity is reduced in the traditional heat treatment process; the tensile strength of the magnesium alloy member treated by the method can reach 411-512MPa, the elongation after fracture can reach 14-17%, and the surface roughness can reach IT8-IT10 level, so that more possibilities are provided for the expansion application of the magnesium alloy member; in addition, the method is simple in process operation, easy to implement and suitable for industrial large-scale production.)

1. A process for plasticizing a magnesium alloy structural member, comprising the steps of: in the heat treatment process, twin defects are introduced into the structure of the magnesium alloy member, and the magnesium alloy member is subjected to aging treatment.

2. Plasticizing process according to claim 1, characterized in that: twin defects are introduced by cold pressing the magnesium alloy component.

3. Plasticizing process according to claim 2, characterized in that: twin crystal defects are introduced by placing the magnesium alloy component in a constant-size normal-temperature die for cold pressing.

4. A plasticising process according to claim 2 or 3, characterised in that: the temperature in the cold pressing process is controlled to be 10-30 ℃, and the total deformation of the magnesium alloy member is controlled to be 3-9%.

5. The plasticizing process of claim 4, wherein when the magnesium alloy member is a Mg-Al based alloy, the plasticizing process step includes: the method comprises the steps of firstly, placing a magnesium alloy component in an atmosphere of 400-420 ℃ for heat preservation for 1-2 hours, then placing the magnesium alloy component in an atmosphere of 100-130 ℃ for heat preservation for 3-8 hours, then placing the magnesium alloy component in a mold with the temperature of 15-25 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation after cold pressing to be 4-7%, then placing the magnesium alloy component after cold pressing in an atmosphere of 170-200 ℃ for heat preservation for 10-16 hours, and finally carrying out forced air cooling.

6. The plasticizing process of claim 4, wherein when the magnesium alloy member is a Mg-Re-Zr/Mn alloy, the plasticizing process step includes: the method comprises the steps of firstly, placing a magnesium alloy component in an atmosphere of 490-510 ℃ for heat preservation for 1-2 hours, then placing the magnesium alloy component in a mold with the temperature of 15-25 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation amount after cold pressing to be 5-6%, then sequentially carrying out two-stage aging treatment on the component after cold pressing, controlling the temperature to be 100-130 ℃ and the time to be 12-30 hours in the primary aging treatment process, controlling the temperature to be 190-230 ℃ and the time to be 18-30 hours in the secondary aging treatment process, and carrying out forced air cooling after aging is completed.

7. The plasticization process according to claim 4, wherein when the magnesium alloy member is Mg-Zn series alloy, the magnesium alloy member is subjected to two-stage aging treatment before and/or after twin defects are introduced.

8. The plasticizing process of claim 7, wherein the magnesium alloy member includes the following elements in percentage by mass: 5.5-6.5% of Zn, 0.5-0.8% of Zr or Mn and the balance of Mg and inevitable impurities; the plasticizing process steps include: firstly, placing a magnesium alloy component in a mold with the temperature of 20-25 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation amount after cold pressing to be 4-5%, then placing the component after cold pressing in the atmosphere with the temperature of 110-120 ℃ for primary aging treatment for 4-8 h, then placing the component in the atmosphere with the temperature of 180-190 ℃ for secondary aging treatment for 12-30 h, and performing forced air cooling after the secondary aging treatment.

9. The plasticizing process of claim 4, wherein the magnesium alloy member includes the following elements in percentage by mass: 2-10% of Gd, 1-4% of Y, 0.2-1% of Zr or Mn and the balance of Mg and inevitable impurities; the plasticizing process steps include: firstly, placing a magnesium alloy component in a die at the temperature of 10-30 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation amount after the cold pressing to be 3-10%, then placing the component after the cold pressing in the atmosphere at the temperature of 100-220 ℃ for aging treatment for 4-30 h, and cooling with strong wind after the aging treatment.

Technical Field

The invention relates to a magnesium alloy heat treatment process, in particular to a plasticizing process of a magnesium alloy member.

Background

At present, the more mature magnesium alloys mainly comprise Mg-Al, Mg-Zn, Mg-Re and other series, wherein the Mg-Al and Mg-Zn series are the most potential magnesium alloy series and are widely applied to the fields of rail vehicles, automobiles, aerospace, weapons and the like. The Mg-Al series alloy has the advantages of easy casting, easy processing, high strength, high corrosion resistance, low cost and the like, is a magnesium alloy series with the most brands and the widest application at present, and can obtain excellent room temperature mechanical properties through solid solution and aging strengthening.

Most magnesium alloy members are obtained by deep processing (such as hot pressing) on the basis of magnesium alloy profiles, and in general, the elongation after fracture of the magnesium alloy profiles is relatively small, for example, the elongation after fracture of the magnesium alloy profile disclosed in document CN109457157A is at most 8.7%, and the elongation after fracture of the magnesium alloy profile processed into a magnesium alloy member is generally further reduced. In addition, although the strength of the magnesium alloy member is greatly increased after heat treatment, the toughness and plasticity thereof are also greatly reduced, which inevitably affects the application range of the magnesium alloy member. Therefore, it is necessary to develop a heat treatment process for simultaneously improving the strength and plasticity of magnesium alloys.

Disclosure of Invention

The invention aims to provide a plasticizing process of a magnesium alloy component.

In order to achieve the purpose, the invention adopts the following technical scheme.

A process for plasticizing a magnesium alloy structural member, the steps comprising: in the heat treatment process, twin defects are introduced into the structure of the magnesium alloy member, and the magnesium alloy member is subjected to aging treatment.

Preferably, the twin defects are introduced by cold pressing the magnesium alloy component.

Preferably, the twin crystal defect is introduced by cold pressing the magnesium alloy member in a constant-size normal-temperature die.

Preferably, the temperature in the cold pressing process is controlled to be 10-30 ℃, and the total deformation of the magnesium alloy component is controlled to be 3-9%.

Preferably, when the magnesium alloy member is a Mg-Al alloy, the plasticizing process includes: the method comprises the steps of firstly, placing a magnesium alloy component in an atmosphere of 400-420 ℃ for heat preservation for 1-2 hours, then placing the magnesium alloy component in an atmosphere of 100-130 ℃ for heat preservation for 3-8 hours, then placing the magnesium alloy component in a mold with the temperature of 15-25 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation after cold pressing to be 4-7%, then placing the magnesium alloy component after cold pressing in an atmosphere of 170-200 ℃ for heat preservation for 10-16 hours, and finally carrying out forced air cooling.

Preferably, when the magnesium alloy component is Mg-Re-Zr/Mn alloy, the plasticizing process comprises the following steps: the method comprises the steps of firstly, placing a magnesium alloy component in an atmosphere of 490-510 ℃ for heat preservation for 1-2 hours, then placing the magnesium alloy component in a mold with the temperature of 15-25 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation amount after cold pressing to be 5-6%, then sequentially carrying out two-stage aging treatment on the component after cold pressing, controlling the temperature to be 100-130 ℃ and the time to be 12-30 hours in the primary aging treatment process, controlling the temperature to be 190-230 ℃ and the time to be 18-30 hours in the secondary aging treatment process, and carrying out forced air cooling after aging is completed.

Preferably, when the magnesium alloy component is Mg-Zn alloy, the magnesium alloy component is subjected to two-stage aging treatment before and/or after twin defects are introduced.

Preferably, the magnesium alloy component comprises the following elements in percentage by mass: 5.5-6.5% of Zn, 0.5-0.8% of Zr or Mn and the balance of Mg and inevitable impurities; the plasticizing process steps include: firstly, placing a magnesium alloy component in a mold with the temperature of 20-25 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation amount after cold pressing to be 4-5%, then placing the component after cold pressing in the atmosphere with the temperature of 110-120 ℃ for primary aging treatment for 4-8 h, then placing the component in the atmosphere with the temperature of 180-190 ℃ for secondary aging treatment for 12-30 h, and performing forced air cooling after the secondary aging treatment.

Preferably, the magnesium alloy component comprises, by mass, 2-10% of Gd, 1-4% of Y, 0.2-1% of Zr or Mn, and the balance of Mg and inevitable impurities; the plasticizing process steps include: firstly, placing a magnesium alloy component in a die at the temperature of 10-30 ℃ for cold pressing to enable twin crystal defects to be introduced into the structure of the magnesium alloy component, controlling the total deformation amount after the cold pressing to be 3-10%, then placing the component after the cold pressing in the atmosphere at the temperature of 100-220 ℃ for aging treatment for 4-30 h, and cooling with strong wind after the aging treatment.

Has the advantages that: the invention leads the strength and the plasticity of the magnesium alloy component to be synchronously improved by introducing twin crystal defects into the structure of the magnesium alloy component and carrying out aging treatment on the magnesium alloy component, thereby solving the problem that the strength is increased but the plasticity is reduced in the traditional heat treatment process; the tensile strength of the magnesium alloy member treated by the method can reach 411-512MPa at room temperature, the elongation after fracture can reach 14-17%, and the surface roughness can reach IT8-IT10 level, so that more possibilities are provided for the expansion and application of the magnesium alloy member; in addition, the method is simple in process operation, easy to implement and suitable for industrial large-scale production.

Detailed Description

The present invention is further described with reference to the following specific embodiments, which should not be construed as limiting the scope of the present invention, and those skilled in the art can make some simple or principle equivalent substitutions or modifications according to the content of the present invention.

A process for plasticizing a magnesium alloy structural member (Mg-7.6 Al-0.4Zn-0.5Mn alloy structural member) comprising the steps of: firstly, preserving heat of a precisely formed Mg-7.6Al-0.4Zn-0.5Mn alloy component for 2 hours in an atmosphere of 400 ℃ for solution treatment, then preserving heat of the component for 8 hours in an atmosphere of 100 ℃, then placing the component in a die at normal temperature for cold pressing, wherein the total deformation after cold pressing is 7%, finally placing the component after cold pressing in an atmosphere of 180 ℃ for heat preservation for 16 hours for aging treatment, and cooling the component by strong wind after aging. After the mechanical property test is finished, the tensile strength of the member is 411MPa, the elongation after fracture is 16.0 percent, and the surface roughness grade of the member is IT9 grade.