阅读说明：本技术 一种镁合金及其制备方法和应用 (Magnesium alloy and preparation method and application thereof ) 是由 房大庆 张晓茹 杨军 刘鹏 龚保罗 于 2020-11-27 设计创作，主要内容包括：本发明公开了一种镁合金及其制备方法和应用,属于合金材料技术领域。该镁合金按重量百分含量计,包括：Zn 6.1-9.0％、RE 0.8-3.6％、Zr 0.3-0.8％,余量为Mg,该镁合金的延伸率为20-28％。其制备方法包括：将Zn源、RE源、Zr源和Mg源混合后熔炼成液态混合金属；将液态混合金属铸造成铸锭；将铸锭在360-400℃下热处理6-10h；将热处理后的铸锭挤压成型,得到镁合金。本发明的镁合金具备高的延伸率,使得所述镁合金可以承受较大的塑性变形；同时热导率可为100-120W·m～(-1)·K～(-1),符合电子设备的热导性能指标；另外,本发明的镁合金还具备较高的强度。该镁合金可用于3C产品领域。(The invention discloses a magnesium alloy and a preparation method and application thereof, belonging to the technical field of alloy materials. The magnesium alloy comprises the following components in percentage by weight: 6.1 to 9.0 percent of Zn, 0.8 to 3.6 percent of RE, 0.3 to 0.8 percent of Zr, and the balance of Mg, and the elongation of the magnesium alloy is 20 to 28 percent. The preparation method comprises the following steps: mixing a Zn source, an RE source, a Zr source and an Mg source, and then smelting into liquid mixed metal; casting the liquid mixed metal into an ingot; carrying out heat treatment on the cast ingot at the temperature of 360-400 ℃ for 6-10 h; and carrying out extrusion forming on the ingot after the heat treatment to obtain the magnesium alloy. The magnesium alloy has high elongation, so that the magnesium alloy can bear large plastic deformation; meanwhile, the thermal conductivity can be 100-120 W.m ‑1 ·K ‑1 The thermal conductivity index of the electronic equipment is met; in addition, the magnesium alloy of the invention also has higher strength. The magnesium isThe alloy can be used in the field of 3C products.)

1. The magnesium alloy is characterized by comprising the following components in percentage by weight: 6.1 to 9.0 percent of Zn, 0.8 to 3.6 percent of RE, 0.3 to 0.8 percent of Zr, and the balance of Mg, wherein the elongation of the magnesium alloy is 20 to 28 percent.

2. The magnesium alloy of claim 1, wherein the weight percent of Zn in the magnesium alloy is 6.1-7.5%.

3. The magnesium alloy according to claim 1 or 2, wherein the weight percentage content of RE in the magnesium alloy is 2.0-2.6%.

4. The magnesium alloy of claim 2, wherein the magnesium alloy has a Zn content of 7.0-7.5 wt% and a RE content of 2.0-2.6 wt%.

5. The magnesium alloy of claim 4, wherein the magnesium alloy has an elongation of 20-25%, a yield strength of 340-.

6. The magnesium alloy of claim 1, wherein the magnesium alloy has a thermal conductivity of 100-^-1·K^-1。

7. The magnesium alloy of claim 1, wherein the RE comprises at least one of La, Ce, Nd, Y, Gd, Ho, Dy, and Er.

8. The magnesium alloy of claim 7, wherein the RE comprises 0.6-2.4% Y, 0-1% Nd, and 0-0.8% Gd and Ce.

9. A method for producing the magnesium alloy according to any one of claims 1 to 8, comprising the steps of:

mixing a Zn source, an RE source, a Zr source and an Mg source, and then smelting into liquid mixed metal;

casting the liquid mixed metal into an ingot;

carrying out heat treatment on the ingot at the temperature of 360-400 ℃ for 6-10 h;

and carrying out extrusion forming on the ingot after the heat treatment to obtain the magnesium alloy.

10. Use of a magnesium alloy according to any one of claims 1 to 8 for the field of 3C products.

Technical Field

The invention relates to a magnesium alloy and a preparation method and application thereof, belonging to the technical field of alloy materials.

Background

The magnesium alloy is a light metal structure material formed by adding other elements into magnesium as a base, has the advantages of low density, high specific strength and specific rigidity, good damping performance, good electromagnetic shielding effect, excellent casting performance, good processing performance and the like, and obtains wide application prospect.

The magnesium alloy can be divided into Mg-Al series alloy, Mg-Mn series alloy and Mg-Zn-Zr series alloy according to different components, wherein the Mg-Zn-Zr series alloy is a high-strength high-toughness magnesium alloy, and the comprehensive performance of the Mg-Zn-Zr series alloy can be further improved by adding rare earth elements into the Mg-Zn-Zr series alloy, so that the Mg-Zn-Zr series alloy has higher tensile strength and yield strength. However, the conventional Mg-Zn-Zr alloy has poor elongation, is easy to crack during casting, and is difficult to dissipate heat generated inside electronic equipment in time when applied to the electronic equipment with large heat generation quantity, thereby influencing the stable operation of the electronic equipment.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems of the existing Mg-Zn-Zr series alloy, the invention provides a magnesium alloy with high elongation and thermal conductivity and a preparation method of the magnesium alloy; in addition, the application of the magnesium alloy in the field of 3C products is also provided.

The technical scheme is as follows: the magnesium alloy comprises the following components: zn 6.1-9.0%, RE 0.8-3.6%, Zr 0.3-0.8%, and Mg for the rest; the elongation of the magnesium alloy is 20-28%.

Optionally, the thermal conductivity of the magnesium alloy is 100-120 W.m^-1·K^-1。

Optionally, the weight percentage of Zn in the magnesium alloy is 6.1-7.5%, the content of Zn exceeds 7.5%, and the elongation and the heat conductivity are reduced to some extent.

Optionally, the RE accounts for 2.0-2.6 wt%. The RE content is lower than 2.0 percent, the elongation of the magnesium alloy is higher, but the strength performance is reduced; the RE content is higher than 2.6%, and the elongation and the strength performance of the magnesium alloy are reduced. This range can provide a magnesium alloy with high elongation while ensuring its strength properties.

When the weight percentage of Zn in the magnesium alloy is 6.1-7.5%, and the weight percentage of RE is 2.0-2.6%, high elongation is obtained, and simultaneously, high thermal conductivity is achieved, and proper strength performance is maintained. Preferably, the thermal conductivity of the magnesium alloy can be 102-118 W.m^-1·K^-1The yield strength can be 293-353MPa, and the tensile strength can be 350-408 MPa.

Optionally, the weight percentage of Zn in the magnesium alloy is 7.0-7.5%, and the weight percentage of RE is 2.0-2.6%. In this case, the magnesium alloy has excellent comprehensive properties, including high elongation, high thermal conductivity, and high strength. Preferably, the elongation of the magnesium alloy can be 20-25%, the yield strength can be 340-353MPa, and the tensile strength can be 390-408 MPa.

Optionally, in the magnesium alloy, RE includes at least one of La, Ce, Nd, Y, Gd, Ho, Dy, and Er. The rare earth element RE takes Y as the main component, Nd is added, Gd and Ce are added, and other rare earth elements are trace. Preferably, RE comprises 0.6-2.4% Y, 0-1% Nd, and 0-0.8% total of Gd and Ce.

The preparation method of the magnesium alloy comprises the following steps:

mixing a Zn source, an RE source, a Zr source and an Mg source, and then smelting into liquid mixed metal;

casting the liquid mixed metal into an ingot;

carrying out heat treatment on the cast ingot for 6-10h under a first temperature condition, wherein the first temperature is 360-400 ℃;

and carrying out extrusion forming on the ingot after the heat treatment to obtain the magnesium alloy.

The application of the magnesium alloy is to apply the magnesium alloy to the field of 3C products.

Has the advantages that: compared with the prior art, the invention has the advantages that: (1) the magnesium alloy has high elongation which can reach 20-28 percent, so thatThe magnesium alloy can bear large plastic deformation; meanwhile, the magnesium alloy has better thermal conductivity which can be 100-^-1·K^-1The thermal conductivity index of the electronic equipment is met; in addition, the magnesium alloy of the invention also has higher strength, and the properties improve the application range of the magnesium alloy; (2) the preparation method of the magnesium alloy carries out heat treatment before extrusion forming, and the heat treatment process can increase the content of Zn element in the matrix, increase the sliding system and improve the elongation percentage of the alloy.

Drawings

FIG. 1 is a flow chart of a process for preparing the magnesium alloy of the present invention.

FIG. 2 is a scanning electron micrograph of a microstructure of a magnesium alloy obtained in example 5;

FIG. 3 is a scanning electron micrograph of the microstructure of the magnesium alloy obtained in example 13.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

The magnesium alloy comprises the following components in percentage by weight: zn 6.1-9.0%, RE 0.8-3.6%, Zr 0.3-0.8%, and Mg for the rest; the elongation of the magnesium alloy is 20-28%.

Specifically, RE (rare earth element) is added into Mg-Zn-Zr series alloy with a certain proportion, the texture of the magnesium alloy can be weakened by the addition of the RE, the coordination capability among all component crystals of the magnesium alloy is improved, the dynamic recrystallization is promoted, and the strength and the plasticity of the magnesium alloy are improved.

The strength of the magnesium alloy can be embodied by yield strength and tensile strength, the yield strength range of the magnesium alloy provided by the invention is 293-353MPa, and preferably, the yield strength range of the magnesium alloy is 340-353 MPa; the tensile strength range of the magnesium alloy provided by the invention is 350-408MPa, and preferably, the tensile strength range of the magnesium alloy is 390-408 MPa. The elongation is directly related to the plasticity of the magnesium alloy, the elongation of the magnesium alloy provided by the invention can reach 20-28%, and preferably, the elongation of the magnesium alloy is 20-25%; the high elongation rate enables the magnesium alloy to bear larger plastic deformation, and the application range of the magnesium alloy is improved.

The strength of the traditional magnesium alloy is generally improved by adding metals such as Al and Mn, the addition of the metals can obviously reduce the heat-conducting property of the magnesium alloy, and when the magnesium alloy is applied to the protection of equipment with higher heat production quantity, the heat inside the equipment is difficult to dissipate in time, so that the service performance and the service life of the equipment are influenced. The magnesium alloy provided by the invention improves the heat-conducting property of the magnesium alloy on the basis of ensuring the yield strength and tensile strength of the magnesium alloy through effectively controlling the addition amounts of Zn, RE and Zr, and the heat conductivity range of the magnesium alloy can be 100-120 W.m^-1·K^-1Preferably, the thermal conductivity range of the magnesium alloy is 102-118 W.m^-1·K^-1. So that the magnesium alloy can be widely applied to the protection field of products with higher heat generation quantity, such as electronic products and the like.

The weight percentage of Zn in the magnesium alloy of the present invention ranges from 6.1 to 9.0%, preferably from 6.1 to 7.5%. After metal Zn is added into the magnesium alloy, when the weight percentage of Zn in the magnesium alloy is 6.1-9.0%, part of the metal Zn is combined with RE and Mg metal to form a quasicrystal phase, the melting point of the quasicrystal phase is higher, dynamic recrystallization can be promoted through a particle-excited nucleation mechanism, the growth of crystal grains is hindered, and the effects of refining the crystal grains of the magnesium alloy and improving the strength of the magnesium alloy are achieved; and the other part of the metal Zn is dissolved in the magnesium alloy matrix in a solid mode to generate lattice distortion, so that the start of intragranular non-basal plane slippage is promoted, and the plastic deformation capacity of the magnesium alloy is improved. However, when the weight percentage of Zn in the magnesium alloy is less than 6.1%, the amount of Zn element that is solid-dissolved in the crystal of the magnesium alloy is reduced, and the elongation of the magnesium alloy is reduced; and when the weight percentage of Zn in the magnesium alloy is higher than 9.0%, more MgZn phase can be formed in the magnesium alloy forming process, and because the melting point of the MgZn phase is lower, the MgZn phase is easy to dissolve in the high-temperature deformation process of the magnesium alloy, the dynamic recrystallization is weakened, the grain size of the magnesium alloy is larger, and the improvement of the plasticity of the magnesium alloy is limited.

The weight percentage of RE in the magnesium alloy of the present invention ranges from 0.8 to 3.6%, preferably from 2.0 to 2.6%. After RE is added into the magnesium alloy, the RE is generally distributed in a crystal boundary, so that the texture of the magnesium alloy can be weakened, and the coordination capability among crystal grains of the magnesium alloy is improved; and RE can form a heat stable second phase in the magnesium alloy forming process, so that dynamic recrystallization is promoted, and the strength and the plasticity of the magnesium alloy are improved.

The weight percentage of Zr in the magnesium alloy of the present invention ranges from 0.3 to 0.8%, preferably from 0.44 to 0.68%. Zr is used as a microalloying element and can be used as nucleation particles in the process of forming the magnesium alloy, so that the nucleation is promoted, the grain size of the magnesium alloy is refined, and the effect of improving the strength of the magnesium alloy is achieved.

As shown in fig. 1, the present invention provides a method for preparing the magnesium alloy, comprising the following steps:

s101, mixing a Zn source, an RE source, a Zr source and an Mg source, and then smelting into liquid mixed metal;

s102, casting the liquid mixed metal into a cast ingot;

s103, carrying out heat treatment on the ingot under a first temperature condition;

and S104, carrying out extrusion forming on the ingot after heat treatment to obtain the magnesium alloy.

Specifically, the casting process in S102 can be realized by a semi-continuous casting process, and by adopting the semi-continuous process, due to rapid water cooling, the obtained crystal grains have small sizes, and the fine crystal grains can simultaneously improve the strength and the elongation of the alloy. In S103, the first temperature range is 360-400 ℃, the heat treatment time is 6-10h, and the heat treatment process before extrusion can increase the content of Zn element in the matrix, increase the slip system and improve the elongation of the alloy. The extrusion molding process parameters in S104 comprise extrusion temperature, extrusion ratio and extrusion speed, wherein the extrusion temperature range is 300-. The shape of the ingot may be a rod, a tube, a block, or a sphere, and the specific shape of the ingot may be set according to the application field of the magnesium alloy and the structure of the application component, which is not limited in the embodiment of the present invention.

The magnesium alloy obtained by the preparation method provided by the embodiment of the invention has higher yield strength and tensile strength, has higher elongation and can bear larger plastic deformation, and meanwhile, the magnesium alloy has better heat-conducting property, so that the application range of the magnesium alloy is improved.

The magnesium alloy provided by the present invention will be described in detail below by way of specific examples and comparative examples.

Example 1

The magnesium alloy includes: zn 6.1g, Y0.8 g, Zr 0.3g, Mg92.8g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 2

The magnesium alloy includes: 6.5g of Zn, 0.8g of Y, 0.3g of Zr and 92.4g of Mg92.4 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 3

The magnesium alloy includes: zn 7.1g, Y0.8 g, Zr 0.3g, Mg91.8g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 4

The magnesium alloy includes: 7.5g of Zn, 0.8g of Y, 0.3g of Zr and 91.4g of Mg91.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 5

The magnesium alloy includes: 9.0g of Zn, 0.8g of Y, 0.3g of Zr and 89.9g of Mg89.9 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy. The microscopic structure thereof is shown in a scanning electron microscope image in FIG. 2.

Example 6

The magnesium alloy includes: zn 7.5g, Y0.6, Nd 0.4(RE 1.0%), Zr 0.3g, Mg91.2g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Zr source and an Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 7

The magnesium alloy includes: zn 7.5g, Y0.6, Nd 0.4, Ce 0.2(RE 1.2%), Zr 0.3g, Mg91.0 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Zr source and an Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 8

The magnesium alloy includes: 7.5g of Zn, 0.6 g of Y, 0.4g of Nd, 0.2g of Ce, 0.6 g of Gd (1.8 percent of RE), 0.3g of Zr and 90.4g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 9

The magnesium alloy includes: zn 7.5g, Y0.6, Nd 0.4, Ce 0.2, Gd 0.6, Ho 0.2(RE 2.0%), Zr 0.3g, Mg90.2g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Ho source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 10

The magnesium alloy includes: 7.5g of Zn, 0.6 g of Y, 0.4g of Nd, 0.2g of Ce, 0.6 g of Gd, 0.2g of Ho, 0.2% of Dy (RE 2.2%), 0.3g of Zr and 90.0g of Mg90.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Ho source, a Dy source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 11

The magnesium alloy includes: zn 7.5g, Y0.6, Nd 0.4, Ce 0.2, Gd 0.6, Ho 0.2, Dy 0.2, La 0.2(RE 2.4%), Zr 0.3g, Mg89.8 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Ho source, a Dy source, a La source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 12

The magnesium alloy includes: 7.5g of Zn, 0.6 g of Y, 0.4g of Nd, 0.2g of Ce, 0.6 g of Gd, 0.2g of Ho, 0.2g of Dy, 0.2g of La, 0.2g of Er (2.6 percent of RE), 0.3g of Zr and 89.6g of Mg89.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Ho source, a Dy source, a La source, an Er source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 13

The magnesium alloy includes: zn 7.5g, Y0.9, Nd 0.4, Ce 0.2, Gd 0.6(RE 2.1%), Zr 0.3g, Mg90.1g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy. The microstructure of the magnesium alloy is shown in a scanning electron microscope image of fig. 3, and the magnesium alloy prepared has small grain size.

Example 14

The magnesium alloy includes: zn 7.5g, Y1.2, Nd 0.4, Ce 0.2, Gd 0.6(RE 2.4%), Zr 0.3g, Mg89.8g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 15

The magnesium alloy includes: zn 7.5g, Y1.4, Nd 0.4, Ce 0.2, Gd 0.6(RE 2.6%), Zr 0.3g, Mg89.6 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 16

The magnesium alloy includes: 6.1g of Zn, 0.9g of Y, 0.4g of Nd, 0.2g of Ce, 0.6 g of Gd (2.1 percent of RE), 0.4g of Zr and 91.4g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 17

The magnesium alloy includes: 6.5g of Zn, 1.1 g of Y, 0.4g of Nd, 0.2g of Ce, 0.6 g of Gd (2.3 percent of RE), 0.3g of Zr and 90.9g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 18

The magnesium alloy includes: zn 7.0g, Y0.9, Nd 0.4, Ce 0.2, Gd 0.6(RE 2.1%), Zr 0.5g, Mg90.4 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 19

The magnesium alloy includes: zn 7.5g, Y1.4, Nd 0.4, Ce 0.2, Gd 0.6(RE 2.6%), Zr 0.5g, Mg89.4 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 20

The magnesium alloy includes: zn 7.5g, Y1.6, Nd 0.4, Ce 0.2, Gd 0.6(RE 2.8%), Zr 0.3g, Mg89.4g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 21

The magnesium alloy includes: zn 7.5g, Y2.1, Nd 0.4, Ce 0.2, Gd 0.6(RE 3.3%), Zr 0.3g, Mg88.9 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 22

The magnesium alloy includes: zn 7.5g, Y2.4, Nd 0.4, Ce 0.2, Gd 0.6(RE 3.6%), Zr 0.3g, Mg88.6 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 23

The magnesium alloy includes: 7.5g of Zn, 0.8g of Y, 0.44g of Zr and 91.26g of Mg91.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 24

The magnesium alloy includes: zn 7.5g, Y0.8 g, Zr 0.52g, Mg91.18g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 25

The magnesium alloy includes: zn 7.5g, Y0.8 g, Zr 0.68g, Mg91.02g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Example 26

The magnesium alloy includes: 7.5g of Zn, 0.8g of Y, 0.80g of Zr and 90.9g of Mg90.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Comparative example 1

The magnesium alloy includes: 5.0g of Zn, 0.8g of Y, 0.3g of Zr and 93.9g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Comparative example 2

The magnesium alloy includes: 9.8g of Zn, 0.8g of Y, 0.3g of Zr and 89.1g of Mg89.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Comparative example 3

The magnesium alloy includes: 6.1g of Zn, 0.5g of Y, 0.3g of Zr and 93.1g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Comparative example 4

The magnesium alloy includes: 6.1g of Zn, 4.0g of Y, 0.3g of Zr and 89.6g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Comparative example 5

The magnesium alloy includes: 6.1g of Zn, 0.8g of Y, 0.18g of Zr and 92.92g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Comparative example 6

The magnesium alloy includes: 6.1g of Zn, 0.8g of Y, 0.92g of Zr and 92.18g of Mg.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, carrying out heat treatment on the cast rod at 360 ℃ for 6 h;

s104, carrying out extrusion forming on the heat-treated cast rod at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

Comparative example 7

The magnesium alloy includes: 7.5g of Zn, 0.6 g of Y, 0.4g of Nd, 0.2g of Ce, 0.6 g of Gd, 0.2g of Ho, 0.2g of Dy, 0.2g of La (2.4 percent of RE), 0.3g of Zr and 89.6g of Mg89.6 g.

The magnesium alloy is obtained by the following preparation method, which specifically comprises the following steps:

s101, uniformly mixing a Zn source, a Y source, an Nd source, a Ce source, a Gd source, a Ho source, a Dy source, a La source, an Er source, a Zr source and a Mg source, and smelting the mixed raw materials into liquid mixed metal;

s102, casting the liquid mixed metal into a casting rod through a semi-continuous casting process;

s103, preheating the casting rod to 340 ℃, and then carrying out extrusion forming at the extrusion temperature of 340 ℃, the extrusion ratio of 15:1 and the extrusion speed of 2mm/S to obtain the magnesium alloy.

TABLE 1 magnesium alloys of examples 1-26 and comparative examples 1-7

As can be seen from Table 1, the magnesium alloys of examples 1 to 26 all had yield strengths of 293MPa or more, and the magnesium alloys of examples 15 and 19 had yield strengths of 353 MPa; the tensile strength can reach more than 350MPa, and the tensile strength of the magnesium alloy of the embodiment 4 reaches 408 MPa; the elongation is more than 20 percent, and the elongation of the magnesium alloy of the embodiment 16 reaches 28 percent; the magnesium alloys of examples 1-26 all had thermal conductivities greater than 90 W.m^-1·K^-1The thermal conductivity of the magnesium alloy of example 1 reached 120 W.m^-1·K^-1。

Comparing the embodiment 1 with the comparative examples 1-2, in the comparative example 1, the yield strength and the tensile strength of the magnesium alloy are low due to the low content of the added Zn, the plasticity is poor, and the elongation is only 16.0%; in comparative example 2, the magnesium alloy had poor plasticity and elongation reduced to 18.0% due to excessively high Zn content, and the thermal conductivity was remarkably reduced to 75 W.m^-1·K^-1。

Comparing the embodiment 1 with the comparative examples 3-4, in the comparative example 3, because the content of the added RE is too low, the yield strength of the magnesium alloy is lower and is only 278MPa, the plasticity is poor, and the elongation is only 16.7%; comparative example 4, in which the RE content was too high, although the elongation of the magnesium alloy was improved, the yield strength and tensile strength were significantly reduced, the heat conductivity was also poor, and heat was generatedConductivity of only 81 W.m^-1·K^-1。

Comparing the embodiment 1 with the comparative examples 5-6, in the comparative example 5, because the Zr content added is too low, the yield strength and the tensile strength of the magnesium alloy are low, the plasticity is poor, and the elongation of the magnesium alloy is only 15.3 percent; in comparative example 6, since the content of Zr added was too large, although the strength of the magnesium alloy was increased as compared with comparative example 1, the plasticity was significantly deteriorated, the elongation was only 14.1%, the heat conductivity was also greatly reduced, and the thermal conductivity was 96W · m^-1·K^-1。

Comparing example 12 with comparative example 7, it can be seen that, compared with the direct extrusion molding after preheating, the mechanical property, plasticity and heat conductivity of the magnesium alloy are obviously improved by performing heat treatment on the cast ingot before extrusion molding.

The magnesium alloy can be applied to the field of 3C products. When the magnesium alloy is applied to a 3C product, the heat inside the 3C product can be quickly transferred to the external environment by virtue of the high thermal conductivity of the magnesium alloy, so that the long-term stable operation of the 3C product is ensured.