CN109022979A - A kind of high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of magnesium alloy materials, in particular to a high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy and a preparation method thereof. The components are: 2-4wt.% Zn, 2-4wt.% Al, 0.5-2wt.% Y, 0.2-1wt.% Sb The total amount of impurity elements Si, Fe, Cu and Ni is less than 0.02wt.%, and the balance is Mg. The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy includes: two processes of smelting and heat treatment, wherein the smelting process steps include: baking material, melting Mg, adding Zn and Al, adding Y, adding Sb, refining And casting, the heat treatment process includes solution and aging treatment. The invention effectively improves the casting structure of the alloy and refines the crystal grains by adding a certain quality of Sb element to the Mg-Zn-Al-Y alloy; forms a second phase with compactness, high melting point and good thermal stability, and makes the alloy The room temperature and high temperature mechanical properties are improved.

Description

A kind of high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy and its preparation method

technical field

The invention relates to the technical field of magnesium alloy materials, in particular to a high-strength heat-resistant magnesium alloy added with Zn, Al, Y and Sb elements.

Background technique

Magnesium alloy has the advantages of low density, wide range of sources, high specific strength and specific stiffness, etc., and is known as "the green engineering material of the 21st century". Wide range of potential applications. At present, a major problem limiting the application of magnesium alloys is that their strength is low, which is difficult to meet the requirements of engineering applications. Therefore, the development of new high-strength magnesium alloys has very important value.

Al is a commonly used alloying element in magnesium-zinc alloys. The ternary phase formed by the combination of Al, Mg and Zn is the main strengthening phase in the aging process. Mg-Zn-Al alloys have the advantages of low cost and good high-temperature mechanical properties. However, the castability and mechanical properties of this alloy are very sensitive to the composition, which greatly limits its application. Studies have shown that a small amount of rare earth elements can refine the microstructure of magnesium alloys, thereby improving the mechanical properties of the alloy at room temperature and high temperature. The addition of rare earth element Y is more common in magnesium alloys. On the one hand, the addition of rare earth elements increases the undercooling of the front of the solid/liquid interface during solidification, thereby refining the alloy structure. On the other hand, the addition of rare earth elements refines the structure. The second phase of the network and form a rare earth phase, thereby changing the fracture mode of the alloy and improving the strength and plasticity of the alloy. However, the addition of a large amount of rare earths increases the cost of the alloy, which is not conducive to commercial applications. Moreover, since the formation of a large number of rare earth phases in the alloy reduces the content of solute on the matrix, when the temperature increases, the dislocation slip velocity increases, and the strength of the alloy, especially the tensile strength, decreases significantly with the increase of temperature, The alloy exhibits lower heat resistance and the aging treatment does not improve the heat resistance significantly. Although reducing the rare earth content in the alloy can increase the concentration of solute in the matrix, it will also lead to the increase of the network second phase, which will reduce the plasticity of the alloy. In addition, the rare earth compounds in the Mg-Zn-Al-Y alloy are mainly distributed at the grain boundaries, and the strengthening effect on the matrix is not good. Because, the following alloying method can be considered to improve the heat resistance of Mg-Zn-Al-Y alloy.

A large number of research results show that adding an appropriate amount of alloying element Sb can significantly improve the high-temperature creep properties of magnesium alloys through fine-grain strengthening and dispersion strengthening, and can significantly increase the high-temperature strength of magnesium alloys. Since the atomic radius difference between Sb and Mg is much greater than 15%, the solubility of Sb in Mg is extremely small, and it is adsorbed on the crystal surface, thereby reducing the surface energy, reducing the growth rate of grains, and refining the grains. . The intermetallic compound Mg ₃ Sb ₂ formed by Sb and Mg first crystallizes out and becomes the heterogeneous nucleation core of the a-Mg phase, and another part of the precipitated phase Mg ₃ Sb ₂ gathers at the front of the primary a-Mg phase, thereby hindering its dendrite The further growth of the organization plays a role in refining the grains. Moreover, Sb is mainly distributed in the matrix in the form of the dispersed second phase Mg ₃ Sb ₂ . The Mg ₃ Sb ₂ phase is in the shape of a short rod, which has the characteristics of compactness, high melting point, good thermal stability, and strengthened grain boundaries. It can still hinder dislocation movement and grain boundary slip (dispersion strengthening) at high temperatures, thereby improving the magnesium alloy Mechanical properties at room temperature and high temperature. After adding Sb, Sb replaced Al and Y (rare earth) preferentially formed high-melting point dispersed particles mainly composed of Y ₂ Sb phase, while the number and size of branched Al ₁₁ Y ₃ phase decreased. The splitting effect of Al ₁₁ Y ₃ relative to the matrix is weakened. Therefore, it is expected to obtain a new Mg-Zn-Al-Y-Sb alloy by adding an appropriate amount of Sb to the Mg-Zn-Al-Y alloy.

Contents of the invention

The object of the present invention is to provide a high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy and its preparation method, which can effectively improve the alloy's strength by adding a certain amount of Sb element to the Mg-Zn-Al-Y alloy. microstructure, grain refinement; the formation of a dense, high melting point, and good thermal stability second phase, which improves the mechanical properties of the alloy at room temperature and high temperature.

To achieve the above object, the present invention provides the following technical solutions:

A high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy, the components of which include: 2-4wt.% Zn, 2-4wt.% Al, 0.5-2wt.% Y, 0.2-1wt.% Sb, The total amount of impurity elements Si, Fe, Cu and Ni is less than 0.02wt.%, and the balance is Mg.

The high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy of the present invention has the following components: 2wt.% Zn, 2wt.% Al, 0.5wt.% Y, 0.2wt.% Sb, impurity element Si The total amount of , Fe, Cu and Ni is 0.01wt.%, and Mg is 95.29wt.%.

The high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy of the present invention has the following components: 3wt.% Zn, 3wt.% Al, 1wt.% Y, 0.5wt.% Sb, impurity elements Si, The total amount of Fe, Cu and Ni is 0.15 wt.%, and Mg is 92.35 wt.%.

The high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy of the present invention has the following components: 4wt.% Zn, 4wt.% Al, 2wt.% Y, 0.8wt.% Sb, impurity elements Si, The total amount of Fe, Cu and Ni is 0.02 wt.%, and Mg is 89.18 wt.%.

The preparation method of any one of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloys of the present invention includes two stages of smelting and heat treatment processes;

Described smelting process comprises the following steps:

(1) Baking material: Weigh pure Mg, pure Zn, pure Al, pure Sb, and Mg-Y master alloy respectively, and then preheat all the above-mentioned raw materials for more than 3 hours to reach 180-250°C for drying;

(2) Melting Mg: putting the dried Mg into a crucible resistance furnace to melt to form magnesium liquid;

(3) Adding Zn and Al: when the temperature of the magnesium liquid reaches 700-740°C, add pure Zn to the magnesium liquid, and after the pure Zn is melted, the melt temperature rises to 700-740°C Add pure Al;

(4) Adding Y: After the pure Al is completely melted, the Mg-Y master alloy is added when the melt temperature rises to 700-740°C;

(5) Adding Sb: After the Mg-Y master alloy is completely melted, pure Sb is added when the melt temperature rises to 700-740°C;

(6) Refining: when the temperature of the melt rises to 720-740°C, add the pre-dried refining agent, stir for 5 minutes, and remove the slag;

(7) Casting: when the temperature of the melt in the step (6) rises to 730-750° C., heat it for 10 minutes, skim off the surface scum, and cast magnesium alloy ingots.

In the method for preparing a high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to the present invention, Y accounts for 25 wt.% in the Mg-Y master alloy.

The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to the present invention, wherein the heat treatment process is to carry out the obtained magnesium alloy ingot at a temperature of 400-410°C for 5-7 hours solution, water quenching; aging treatment at 180-190° C. for 18-19 hours on the solution-treated magnesium alloy ingot to obtain high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to the present invention, wherein, the smelting process is carried out under the protection condition of mixed gas of SF ₆ and CO ₂ .

The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to the present invention, wherein, in the step (6) of the smelting process, the casting steel mold is preheated to 180-250°C.

The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy of the present invention, wherein, the solid solution treatment in the heat treatment process is carried out under the protection of a sulfur-containing atmosphere,

Compared with prior art, the beneficial effect of the present invention is:

(1) The present invention adopts Zn as the first component, and the addition of Zn element can improve the castability of the alloy, and simultaneously forms a strengthening phase with Mg; the present invention adopts Al as the second component, and Al is an effective strengthening agent in magnesium alloys , the addition of Al can effectively improve the hardness of the alloy; the present invention adopts Y as the third component, and the addition of Y can refine the microstructure of the alloy, improve the strength and plasticity of the alloy, and improve the mechanical properties of the alloy; the present invention adopts Sb as the third component Four components, Sb element can effectively improve the casting structure of the alloy, making the coarse dendrites become finer and more dispersed. At the same time, a second phase with density, high melting point and good thermal stability is formed, and the room temperature and high temperature mechanical properties of the alloy are improved at the same time; the room temperature and high temperature mechanical properties of the alloy are improved;

(2) The processing technology of the present invention is simple and convenient to operate.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

A high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy, the components of which include: 2-4wt.% Zn, 2-4wt.% Al, 0.5-2wt.% Y, 0.2-1wt.% Sb, The total amount of impurity elements Si, Fe, Cu and Ni is less than 0.02wt.%, and the balance is Mg.

The wt.% refers to the percentage of the components in the total mass of the configured alloy, and the total mass is the sum of the mass of Mg, Zn, Al, Sb and Mg-Y master alloy.

Its preparation method is divided into two stages of smelting and heat treatment process:

Wherein, the smelting process is carried out under the protection condition of mixed gas of _SF6 and _CO2 , and the steps are as follows:

(1) Baking material: Weigh pure Mg, pure Zn, pure Al, pure Sb, and Mg-Y master alloy respectively, and then preheat all the above-mentioned raw materials for more than 3 hours to reach 180-250°C for drying;

(2) Melting Mg: putting the dried Mg into a crucible resistance furnace to melt to form magnesium liquid;

(3) Adding Zn and Al: when the temperature of the magnesium liquid reaches 700-740°C, add pure Zn to the magnesium liquid, and after the pure Zn is melted, the melt temperature rises to 700-740°C Add pure Al;

(4) Adding Y: After the pure Al is completely melted, the Mg-Y master alloy is added when the melt temperature rises to 700-740°C;

(5) Adding Sb: After the Mg-Y master alloy is completely melted, pure Sb is added when the melt temperature rises to 700-740°C;

(6) Refining: when the temperature of the melt rises to 720-740°C, add the pre-dried refining agent, stir for 5 minutes, and remove the slag;

(7) Casting: when the temperature of the melt in the step (6) rises to 730-750° C., heat it for 10 minutes, skim off the surface scum and cast magnesium alloy ingot;

Heat treatment process: solid solution the obtained magnesium alloy ingot at a temperature of 400-410° C. for 5-7 hours, and water quenching. Perform aging treatment at 180-190°C for 18-19 hours on the magnesium alloy ingot after solution treatment to obtain high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

In the preparation method of the high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy, Y accounts for 25wt.% in the Mg-Y master alloy, that is, a Mg-25wt.%Y master alloy is used.

Example 2

A high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy, the mass percentage of its components is: 2wt.% Zn, 2wt.% Al, 0.5wt.% Y, 0.2wt.% Sb, impurity element Si The total amount of , Fe, Cu and Ni is 0.01wt.%, and Mg is 95.29wt.%.

The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy is as follows:

First, the smelting process is carried out, and the whole smelting process is carried out under the protection condition of the mixed gas of _SF6 and _CO2 , specifically:

(1) Weigh pure Mg, pure Zn, pure Al, Mg-Y master alloy and pure Sb respectively. Then, preheat all the above-mentioned raw materials for more than 3 hours to reach 180°C for drying.

(2) The dried pure Mg is melted in a crucible resistance furnace protected by SF ₆ /CO ₂ gas. When the temperature of the molten magnesium reaches 700°C, 2wt.% pure Zn is added.

(3) When the melt temperature rises to 700° C. after pure Zn is melted, 2 wt.% pure Al is directly added to the magnesium liquid.

(4) Add Mg-Y master alloy when the melt temperature rises to 700°C after the pure Al is completely melted. , so that Y finally accounts for 0.5wt.% in the total mass of the prepared high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

(5) After the Mg-Y master alloy is completely melted, add 0.2wt.% pure Sb when the melt temperature drops to 700°C.

(6) When the temperature of the melt rises to 750° C., keep it warm for 10 minutes, skim off surface scum and cast magnesium alloy ingots, where the steel mold used for casting is preheated to 180° C.

Heat treatment process: the obtained magnesium alloy ingot is subjected to solid solution at 400° C. for 7 hours, and water quenched. The magnesium alloy ingot after solution treatment is subjected to aging treatment at 180° C. for 19 hours to obtain a high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

The mechanical properties of the T6 state of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy are:

At room temperature, the yield strength is 190MPa, the tensile strength is 266MPa, and the elongation is 11%; at 150°C, the yield strength is 151MPa, the tensile strength is 216MPa, and the elongation is 21%.

Example 3

The components and mass percentages of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy are: 3wt.% Zn, 3wt.% Al, 1wt.% Y, 0.5wt.% Sb, impurity elements Si, Fe, The total amount of Cu and Ni is 0.015 wt.%, and Mg is 92.485 wt.%.

The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy is as follows:

First, the smelting process is carried out, and the whole smelting process is carried out under the protection condition of the mixed gas of _SF6 and _CO2 , specifically:

(1) Weigh pure Mg, pure Zn, pure Al, Mg-Y master alloy and pure Sb respectively. Then, preheat all the above-mentioned raw materials for more than 3 hours to reach 200° C. for drying.

(2) The dried pure Mg is melted in a crucible resistance furnace protected by SF ₆ /CO ₂ gas. After the magnesium liquid temperature reaches 720 ℃, add 3wt.% pure Zn.

(3) When the melt temperature rises to 720°C after pure Zn is melted, add 3wt.% pure Al directly into the magnesium solution.

(4) Add Mg-Y master alloy when the melt temperature rises to 720°C after the pure Al is completely melted. , so that Y finally accounts for 1wt.% in the total mass of the prepared high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

(5) After the Mg-Y master alloy is completely melted, add 0.5wt.% pure Sb when the melt temperature drops to 720°C.

(6) When the temperature of the melt rises to 740°C, keep it warm for 10 minutes, skim off the scum on the surface and cast the magnesium alloy ingot. The steel mold used for casting needs to be heated to 200°C in advance.

Heat treatment process: the obtained magnesium alloy ingot is subjected to solid solution at a temperature of 410° C. for 5 hours, and water quenched. The magnesium alloy ingot after solution treatment is subjected to aging treatment at 190° C. for 18 hours to obtain a high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

The mechanical properties of the T6 state of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy are:

At room temperature, the yield strength is 208MPa, the tensile strength is 297MPa, and the elongation is 9.2%; at 150°C, the yield strength is 168MPa, the tensile strength is 258MPa, and the elongation is 19.2%.

Example 4

The components and mass percentages of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy are: 4wt.% Zn, 4wt.% Al, 2wt.% Y, 0.8wt.% Sb, impurity elements Si, Fe, The total amount of Cu and Ni is 0.02 wt.%, and Mg is 89.18 wt.%.

The preparation method of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy is as follows:

First, the smelting process is carried out, and the whole smelting process is carried out under the protection condition of the mixed gas of _SF6 and _CO2 , specifically:

(1) Weigh pure Mg, pure Zn, pure Al, Mg-Y master alloy and pure Sb respectively. Then, preheat all the above-mentioned raw materials for more than 3 hours to reach 250° C. for drying.

(2) The dried pure Mg is melted in a crucible resistance furnace protected by SF ₆ /CO ₂ gas. When the temperature of the molten magnesium reached 740°C, 4wt.% pure Zn was added.

(3) When the melt temperature rises to 740° C. after pure Zn is melted, add 4 wt.% pure Al directly into the magnesium liquid.

(4) After pure Al is completely melted, when the melt temperature rises to 740°C, add Mg-Y master alloy, which is Mg-25wt.%Y, that is, Y accounts for 25wt.% in Mg-25wt.%Y master alloy , so that Y finally accounts for 2wt.% in the total mass of the prepared high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

(5) After the Mg-Y master alloy is completely melted, add 0.8wt.% pure Sb when the melt temperature drops to 740°C.

(6) When the temperature of the melt rises to 730°C, keep it warm for 10 minutes, skim off the scum on the surface and cast the magnesium alloy ingot. The steel mold used for casting needs to be heated to 250°C in advance.

Heat treatment process: the obtained magnesium alloy ingot is subjected to solid solution at a temperature of 410° C. for 6 hours, and water quenched. The magnesium alloy ingot after solution treatment is subjected to aging treatment at 188° C. for 19 hours to obtain a high-strength and heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy.

The mechanical properties of the T6 state of the high-strength heat-resistant Mg-Zn-Al-Y-Sb magnesium alloy are:

At room temperature, the yield strength is 228MPa, the tensile strength is 305MPa, and the elongation is 8%; at 150°C, the yield strength is 187MPa, the tensile strength is 265MPa, and the elongation is 18.2%.

In order to highlight the beneficial effects of the present invention, the following comparative examples are given as examples.

Comparative example 1

A kind of Mg-Zn-Al-Y-Sb magnesium alloy, its composition and mass percent are: 4wt.% Zn, 4wt.% Al, 2wt.% Y, 0.1wt.% Sb, impurity element Si, Fe, The total amount of Cu and Ni is 0.02 wt.%, and Mg is 89.88 wt.%.

Its preparation method is:

First, the smelting process is carried out, and the whole smelting process is carried out under the protection condition of SF6 and CO ₂ mixed gas, specifically:

(1) Weigh pure Mg, pure Zn, pure Al, Mg-Y master alloy and pure Sb respectively. Then, preheat all the above-mentioned raw materials for more than 3 hours to reach 250° C. for drying.

(2) Put the dried pure Mg into a crucible resistance furnace protected by SF6/ _CO2 gas for melting. When the temperature of the molten magnesium reached 740°C, 4wt.% pure Zn was added.

(3) When the melt temperature rises to 740° C. after pure Zn is melted, add 4 wt.% pure Al directly into the magnesium liquid.

(4) After pure Al is completely melted, when the melt temperature rises to 740°C, add Mg-Y master alloy, which is Mg-25wt.%Y, that is, Y accounts for 25wt.% in Mg-25wt.%Y master alloy , so that Y finally accounts for 2wt.% in the total mass of the prepared Mg-Zn-Al-Y-Sb magnesium alloy.

(5) After the Mg-Y master alloy is completely melted, add 0.1wt.% pure Sb when the melt temperature drops to 740°C.

(6) When the temperature of the melt rises to 730°C, keep it warm for 10 minutes, skim off the scum on the surface and cast the magnesium alloy ingot. The steel mold used for casting needs to be heated to 250°C in advance.

Heat treatment process: the obtained magnesium alloy ingot is subjected to solid solution at 400° C. for 6 hours, and water quenched. The magnesium alloy ingot after the solution treatment is subjected to aging treatment at a temperature of 180° C. for 19 hours to obtain a Mg—Zn—Al—Y—Sb magnesium alloy.

The mechanical properties of the T6 state of the Mg-Zn-Al-Y-Sb magnesium alloy are:

At room temperature, the yield strength is 158MPa, the tensile strength is 235MPa, and the elongation is 21%; at 150°C, the yield strength is 110MPa, the tensile strength is 195MPa, and the elongation is 30%.

Comparative example 2

A kind of Mg-Zn-Al-Y-Sb magnesium alloy, its composition and its mass percent are: 4wt.%Zn, 4wt.%Al, 3wt.%Y, 1.5wt.%Sb, impurity elements Si, Fe, The total amount of Cu and Ni is 0.01 wt.%, and Mg is 87.49 wt.%.

Its preparation method is:

First, the smelting process is carried out, and the whole smelting process is carried out under the protection condition of the mixed gas of _SF6 and _CO2 , specifically:

(1) Weigh pure Mg, pure Zn, pure Al, Mg-Y master alloy and pure Sb respectively. Then, preheat all the above-mentioned raw materials for more than 3 hours to reach 250° C. for drying.

(2) The dried pure Mg is melted in a crucible resistance furnace protected by SF ₆ /CO ₂ gas. When the temperature of the molten magnesium reached 740°C, 4wt.% pure Zn was added.

(3) When the melt temperature rises to 740° C. after pure Zn is melted, add 4 wt.% pure Al directly into the magnesium liquid.

(4) After pure Al is completely melted, when the melt temperature rises to 740°C, add Mg-Y master alloy, which is Mg-25wt.%Y, that is, Y accounts for 25wt.% in Mg-25wt.%Y master alloy , so that Y finally accounts for 3wt.% in the total mass of the prepared Mg-Zn-Al-Y-Sb magnesium alloy.

(5) After the Mg-Y master alloy is completely melted, add 1.5wt.% pure Sb when the melt temperature drops to 740°C.

(6) When the temperature of the melt rises to 730°C, keep it warm for 10 minutes, skim off the scum on the surface and cast the magnesium alloy ingot. The steel mold used for casting needs to be heated to 250°C in advance.

Heat treatment process: the obtained magnesium alloy ingot is subjected to solid solution at a temperature of 410° C. for 6 hours, and water quenched. The magnesium alloy ingot after solution treatment is subjected to aging treatment at a temperature of 180° C. for 18 hours to obtain a Mg—Zn—Al—Y—Sb magnesium alloy.

The mechanical properties of the T6 state of the Mg-Zn-Al-Y-Sb magnesium alloy are:

At room temperature, the yield strength is 168MPa, the tensile strength is 245MPa, and the elongation is 7%; at 150°C, the yield strength is 125MPa, the tensile strength is 215MPa, and the elongation is 12.2%.

Comparative example 3

A kind of Mg-Zn-Al-Y-Sb magnesium alloy, its composition and mass percent are: 4wt.% Zn, 4wt.% Al, 0.3wt.% Y, 0.15wt.% Sb, impurity element Si, Fe The total amount of , Cu and Ni is 0.05wt.%, and Mg is 91.5wt.%.

Its preparation method is:

First, the smelting process is carried out, and the whole smelting process is carried out under the protection condition of the mixed gas of _SF6 and _CO2 , specifically:

(1) Weigh pure Mg, pure Zn, pure Al, Mg-Y master alloy and pure Sb respectively. Then, preheat all the above-mentioned raw materials for more than 3 hours to reach 250° C. for drying.

(2) The dried pure Mg is melted in a crucible resistance furnace protected by SF ₆ /CO ₂ gas. When the temperature of the molten magnesium reached 740°C, 4wt.% pure Zn was added.

(3) When the melt temperature rises to 740° C. after pure Zn is melted, add 4 wt.% pure Al directly into the magnesium liquid.

(4) After pure Al is completely melted, when the melt temperature rises to 740°C, add Mg-Y master alloy, which is Mg-25wt.%Y, that is, Y accounts for 25wt.% in Mg-25wt.%Y master alloy , so that Y finally accounts for 0.3wt.% in the total mass of the prepared Mg-Zn-Al-Y-Sb magnesium alloy.

(5) Add 0.15wt.% pure Sb when the melt temperature drops to 740°C after the Mg-Y master alloy is completely melted.

(6) When the temperature of the melt rises to 730°C, keep it warm for 10 minutes, skim off the scum on the surface and cast the magnesium alloy ingot. The steel mold used for casting needs to be heated to 250°C in advance.

Heat treatment process: the obtained magnesium alloy ingot is subjected to solid solution at a temperature of 410° C. for 6 hours, and water quenched. The magnesium alloy ingot after the solution treatment is subjected to aging treatment at a temperature of 190° C. for 19 hours to obtain a Mg—Zn—Al—Y—Sb magnesium alloy.

The mechanical properties of the T6 state of the Mg-Zn-Al-Y-Sb magnesium alloy are:

At room temperature, the yield strength is 161MPa, the tensile strength is 230MPa, and the elongation is 19%; at 150°C, the yield strength is 111MPa, the tensile strength is 180MPa, and the elongation is 23%.

By comparing the mechanical properties of the Mg-Zn-Al-Y-Sb magnesium alloy prepared in Example 2-4 and Comparative Example 1-3, it can be seen that the performance of the magnesium alloy in Example 2-4 is far better than that of Comparative Example 1-3 Magnesium alloy performance, especially the best performance with embodiment 3. And when Y exceeds 0.5～2wt.%, Sb element dosage exceeds 0.2～1wt.% or impurity element is greater than 0.02wt.%, the mechanical properties of the obtained Mg-Zn-Al-Y-Sb magnesium alloy at room temperature and high temperature Performance will be greatly reduced.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications and substitutions can be made to these embodiments without departing from the principle and spirit of the present invention. and modifications, the scope of the invention is defined by the appended claims and their equivalents.

Claims (10)

1. a kind of high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy, which is characterized in that its component includes: 2~4wt.%Zn, 2~ The total amount of 4wt.%Al, 0.5~2wt.%Y, 0.2~1wt.%Sb, impurity element S i, Fe, Cu and Ni are less than 0.02wt.%, Surplus is Mg.

2. high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 1, which is characterized in that its component are as follows: 2wt.%Zn, 2wt.%Al, 0.5wt.%Y, 0.2wt.%Sb, the total amount of impurity element S i, Fe, Cu and Ni are 0.01wt.%, Mg is 95.29wt.%.

3. high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 1, which is characterized in that its component are as follows: 3wt.%Zn, 3wt.%Al, 1wt.%Y, 0.5wt.%Sb, the total amount of impurity element S i, Fe, Cu and Ni are 0.15wt.%, Mg For 92.35wt.%.

4. high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 1, which is characterized in that its component are as follows: 4wt.%Zn, 4wt.%Al, 2wt.%Y, 0.8wt.%Sb, the total amount of impurity element S i, Fe, Cu and Ni are 0.02wt.%, Mg For 89.18wt.%.

5. the preparation method of any high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy of claim 1-4, it is characterised in that: Including being divided into two stages of melting and heat treatment process；

The smelting technology the following steps are included:

(1) baking material: weighing pure Mg, pure Zn, pure Al, pure Sb, Mg-Y intermediate alloy respectively, then that above-mentioned all raw material difference are pre- Reach 180~250 DEG C to be dried within heat 3 hours or more；

(2) it melts Mg: the pure Mg after drying being put into fusing in crucible electrical resistance furnace and forms magnesium liquid；

(3) add Zn and Al: when the temperature of the magnesium liquid reaches 700~740 DEG C, pure Zn being added into the magnesium liquid, to described After pure Zn fusing, pure Al is added when ging up to 700~740 DEG C in melt temperature；

(4) plus Y: after the pure Al is completely melt, Mg-Y intermediate alloy is added when ging up to 700~740 DEG C in melt temperature；

(5) plus Sb: after the Mg-Y intermediate alloy is completely melt, pure Sb is added when ging up to 700~740 DEG C in melt temperature；

(6) it refines: when melt temperature gos up to 720~740 DEG C, the refining agent dried in advance is added, stirs 5 minutes, skims；

(7) it casts: keeping the temperature 10 minutes when the melt temperature in the step (6) gos up to 730~750 DEG C, it is floating to skim surface Slag and magnesium alloy ingot of casting.

6. the preparation method of high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 5, it is characterised in that: institute It states Y in Mg-Y intermediate alloy and accounts for 25wt.%.

7. the preparation method of high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 5 or 6, it is characterised in that: The heat treatment process is the solid solution carried out the obtained magnesium alloy ingot at a temperature of 400~410 DEG C 5~7 hours, water It quenches；The ageing treatment that 18~19 hours are carried out at a temperature of carrying out 180~190 DEG C to the magnesium alloy ingot after solution treatment, obtains height Strong heat-resisting Mg-Zn-Al-Y-Sb magnesium alloy.

8. the preparation method of high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 7, it is characterised in that: institute Smelting technology is stated in SF₆And CO₂It is carried out under the conditions of mixed gas protected.

9. the preparation method of high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 8, it is characterised in that: institute Casting is previously heated to 180~250 DEG C with steel die in the step of stating smelting technology (6).

10. the preparation method of high-strength temperature-resistant Mg-Zn-Al-Y-Sb magnesium alloy according to claim 9, it is characterised in that: institute The solution treatment stated in heat treatment process carries out under sulfur-bearing atmosphere protection.