CN102828094A - Deforming magnesium alloy and preparation method thereof - Google Patents

Abstract

The invention provides a deformed magnesium alloy and a preparation method thereof. In terms of mass percentage, the deformed magnesium alloy includes 0.1%~10% neodymium, 10%~12% gadolinium, 3%~5% yttrium, 0.5%~ 2% zinc, 0.3%~0.8% zirconium, the rest magnesium and unavoidable impurities. Compared with the prior art WE54, the present invention adds rare earth elements neodymium, gadolinium and yttrium into the Mg-Zn-Zr magnesium alloy. Firstly, after the addition of zinc, a large number of elongated Mg ₁₂ YZn precipitates are formed at the grain boundaries of the alloy, which can prevent the slippage of the grain boundary at high temperature and improve the high temperature stability of the alloy. The plane dislocation slip improves the mechanical properties of the alloy; secondly, three rare earth elements, gadolinium, yttrium and neodymium are added, and the interaction between rare earth elements can be used to reduce the solid solubility of gadolinium, yttrium and neodymium in the magnesium matrix, Promote the formation of precipitated phases and improve the mechanical properties of the alloy.

Description

A kind of wrought magnesium alloy and preparation method thereof

technical field

The invention belongs to the technical field of metal materials, and in particular relates to a deformed magnesium alloy and a preparation method thereof.

Background technique

Magnesium alloy is the lightest structural metal material with a density of 1.75~1.90g/cm ³ , which is only 2/3 of aluminum alloy and 1/4 of steel. Compared with other metal structural materials, magnesium alloy has a series of advantages such as high specific strength, specific stiffness, shock absorption, electromagnetic shielding and radiation resistance, easy cutting, easy recycling, etc. It is widely used in automobiles, electronic appliances, communications, The aerospace and national defense military industry has extremely important application value and broad application prospects. It is the third type of metal structural material developed after steel and aluminum alloy. According to different processing methods, magnesium alloy materials are mainly divided into two categories: cast magnesium alloy and wrought magnesium alloy. Deformed magnesium alloys refer to magnesium alloys that can be processed by plastic forming methods such as extrusion, rolling, forging, and impact. Through the control of material structure and the application of heat treatment processes, higher strength and better Excellent ductility and more diverse mechanical properties to meet the needs of more structural parts.

Wrought magnesium alloys mainly include Mg-Al, Mg-Zn, Mg-RE, Mg-Zr and other alloy systems, among which the most common alloy systems are Mg-Al-Zn and Mg-Zn-Zr alloys. Mg-Al-Zn series magnesium alloy is currently the most widely used alloy system at room temperature. Its main characteristics are high strength, heat treatment strengthening, and good casting performance. However, the Mg ₁₇ Al ₂₂ phase in this series magnesium alloy It grows rapidly under high temperature conditions, which leads to a decrease in the mechanical properties of the alloy and cannot be used as a high temperature structural part. There are a large number of massive eutectic phases Mg ₇ Zn ₃ , MgZn, etc. distributed at the grain boundaries of Mg-Zn-Zr alloys. The melting points of the eutectic phases are all lower than 340°C. After softening, they cannot pin the grain boundaries and hinder Dislocation movement, resulting in poor high temperature performance of Mg-Zn-Zr alloys.

Rare earth elements have been widely used as alloying elements to improve the heat resistance of wrought magnesium alloys. Most rare earth elements have a large solid solubility limit in magnesium, and the solid solubility decreases sharply as the temperature decreases, and a larger solid solubility limit can be obtained. The degree of supersaturation, so that in the subsequent aging process, the dispersed, high melting point rare earth compound phase is precipitated; the rare earth element can also refine the grain, improve the strength at room temperature, and distribute in the grain and grain boundary. Rare earth compounds can still pin the intragranular dislocation and grain boundary slip at high temperature, thereby improving the high temperature strength of the magnesium alloy.

Among them, WE54 is a typical rare earth magnesium alloy containing neodymium, and its composition is Mg-5.1%Y-3.2%RE(1.5%~2%Nd)-0.5%Zr, which is currently a commercially available magnesium alloy. Alloy, the heat-resistant temperature can reach 300 ℃, and after heat treatment, the corrosion resistance is also better than other high-temperature magnesium alloys, but the heat resistance is not stable enough, the strength drops more at high temperatures, and its mechanical properties need to be improved.

Contents of the invention

In view of this, the technical problem to be solved by the present invention is to provide a wrought magnesium alloy and a preparation method thereof, the wrought magnesium alloy has better high temperature stability and higher mechanical properties.

The invention provides a deformed magnesium alloy, comprising: 0.1wt%-10wt% neodymium, 10wt%-12wt% gadolinium, 3wt%-5wt% yttrium, 0.5wt%-2wt% zinc, 0.3wt%-0.8 wt% of zirconium, the balance of magnesium and unavoidable impurities.

The invention provides a method for preparing a deformed magnesium alloy, comprising the following steps:

A) Melt and alloy magnesium ingots, zinc ingots, gadolinium sources, neodymium sources, yttrium sources and zirconium sources, and obtain magnesium melts after refining. The magnesium melts include 0.1wt% 10wt% neodymium, 10wt%~12wt% % gadolinium, 3wt%~5wt% yttrium, 0.5wt%~2wt% zinc, 0.3wt%~0.8wt% zirconium, the rest magnesium and unavoidable impurities;

B) Casting the magnesium melt and extruding it to obtain a deformed magnesium alloy.

Preferably, the gadolinium source is gadolinium ingot and/or magnesium-gadolinium master alloy ingot.

Preferably, the neodymium source is a neodymium ingot and/or a magnesium-neodymium master alloy ingot.

Preferably, the yttrium source is yttrium ingot and/or magnesium-yttrium master alloy ingot.

Preferably, the zirconium source is a zirconium ingot and/or a magnesium-zirconium master alloy ingot.

Preferably, the step B is specifically:

The magnesium melt is cast, solid solution treated, extruded, and subjected to aging treatment to obtain a deformed magnesium alloy.

Preferably, the step A is specifically:

Under a protective atmosphere, add magnesium ingots, zinc ingots and covering agent to the melting furnace, heat up to 730°C~750°C, add gadolinium source and neodymium source, continue to heat up to 760°C~780°C, add yttrium source, zirconium source and A magnesium melt is obtained after refining with a refining agent; the magnesium melt includes 0.1wt%-10wt% neodymium, 10wt%-12wt% gadolinium, 3wt%-5wt% yttrium, 0.5wt%-2wt% zinc, 0.3 wt%~0.8wt% zirconium, the rest magnesium and unavoidable impurities.

Preferably, the covering agent comprises 30-40wt% of MgCl ₂ , 15-25wt% of KCl/NaCl, 15-25wt% of CaF/NaF and the balance of BaCl ₂ .

Preferably, the refining agent comprises 50-60wt% KCl/NaCl, 15-20wt% BaCl ₂ , 20-30wt% CaCl ₂ and the balance MgCO ₃ /Na ₂ CO ₃ .

The invention provides a wrought magnesium alloy and a preparation method thereof. The wrought magnesium alloy includes 0.1wt% to 10wt% of neodymium, 10wt% to 12wt% of gadolinium, 3wt% to 5wt% of yttrium, and 0.5wt% to 2wt% zinc, 0.3wt%~0.8wt% zirconium, the rest of magnesium and unavoidable impurities. Compared with the prior art WE54, the present invention adds rare earth elements neodymium, gadolinium and yttrium into the Mg-Zn-Zr ternary magnesium alloy. First, after the addition of zinc, a large number of elongated Mg ₁₂ YZn precipitates are formed at the grain boundaries in the alloy, which can prevent the grain boundary from slipping under high temperature conditions, improve the high temperature stability of the alloy, and the precipitates are uniform along the extrusion direction arrangement, which can hinder the slippage of basal plane dislocations and improve the mechanical properties of the alloy; secondly, three rare earth elements, gadolinium, yttrium and neodymium, can be used to reduce the interaction between gadolinium, yttrium and neodymium in the magnesium matrix. The solid solubility promotes the formation of precipitated phases and improves the mechanical properties of the alloy.

The experimental results show that the tensile strength of the deformed magnesium alloy prepared by the present invention at room temperature (25°C) is greater than 420MPa, the yield strength is greater than 320MPa, the tensile strength at 200°C is greater than 380MPa, the yield strength is greater than 300MPa, and the tensile strength at 250°C Greater than 350MPa, the yield strength is greater than 290MPa, the tensile strength at 300°C is greater than 225MPa, and the yield strength is greater than 190MPa.

Description of drawings

Fig. 1 is the extruded metallographic structure diagram of the wrought magnesium alloy prepared in Example 2 of the present invention;

Fig. 2 is a transmission electron microscope microstructure diagram of the deformed magnesium alloy prepared in Example 2 of the present invention.

Detailed ways

The invention provides a deformed magnesium alloy, comprising 0.1wt%-10wt% neodymium, 10wt%-12wt% gadolinium, 3wt%-5wt% yttrium, 0.5wt%-2wt% zinc, 0.3wt%-0.8 wt% of zirconium, the balance of magnesium and unavoidable impurities.

Wherein, the content of the neodymium is preferably 0.5wt%~8wt%, more preferably 0.5wt%~6wt%, more preferably 0.5wt%~4wt%; the content of the gadolinium is preferably 10wt%~11.5wt%; The content of the yttrium is preferably 3.5wt% ~ 5wt%, more preferably 3.5wt% ~ 4.5wt%; the content of the zinc is preferably 0.5wt% ~ 1.5wt%, more preferably 0.5wt% ~ 1wt%; The content of the zirconium is preferably 0.4wt% ~ 0.8wt%, more preferably 0.4wt% ~ 0.6wt%, more preferably 0.5wt% ~ 0.6wt%; the content of the impurity is less than 0.02%, the impurity is Unavoidable impurities, well known to those skilled in the art, typically include elemental silicon, iron, copper and nickel.

The present invention also provides a method for preparing a deformed magnesium alloy, which includes the following steps: A) melting and alloying magnesium ingots, zinc ingots, gadolinium sources, neodymium sources, yttrium sources and zirconium sources, and obtaining a magnesium melt after refining, The magnesium melt includes 0.1wt%~10wt% of neodymium, 10wt%~12wt% of gadolinium, 3wt%~5wt% of yttrium, 0.5wt%~2wt% of zinc, 0.3wt%~0.8wt% of zirconium, The remaining magnesium and unavoidable impurities, the content of which is less than 0.02%; B) casting the magnesium melt and extruding it to obtain a deformed magnesium alloy.

In order to clearly illustrate the present invention, the experimental processes of step A and step B are described in detail below respectively.

According to the step A of the present invention, it is as follows: under a protective atmosphere, add magnesium ingots, zinc ingots and covering agent to the melting furnace, raise the temperature to 730°C~750°C, preferably 730°C~740°C, add gadolinium source and neodymium source, continue to heat up to 760°C~780°C, preferably 770°C~780°C, add yttrium source and zirconium source, cool down to 730°C~750°C, preferably 730°C~740°C, add refining agent, and obtain magnesium after refining Melt, the magnesium melt includes the various elements and contents described above for the magnesium alloy, which will not be repeated here.

According to this feeding sequence, the possibility of compound formation by interaction between different elements can be reduced, thereby ensuring the accuracy of the alloy composition and improving the quality of the alloy.

The protective atmosphere is a protective atmosphere well known to those skilled in the art, preferably a mixed gas with a volume fraction of 99% carbon dioxide and 1% sulfur hexafluoride. Sulfur hexafluoride has a good protective effect on magnesium alloys, and can form a thick layer of relatively stable MgF ₂ compound protective film with good protective effect on the surface of magnesium melt.

Wherein, the gadolinium source is a gadolinium ingot and/or a magnesium-gadolinium master alloy ingot, preferably a magnesium-gadolinium master alloy ingot containing 20wt% magnesium; the neodymium source is a neodymium ingot and/or a magnesium-gadolinium master alloy ingot, preferably containing Magnesium-Nd master alloy ingot with 20wt% magnesium; the yttrium source is yttrium ingot and/or magnesium-yttrium master alloy ingot, preferably a magnesium-yttrium master alloy ingot containing 20wt% magnesium; the zirconium source is zirconium ingot and/or magnesium The zirconium master alloy ingot is preferably a magnesium-zirconium master alloy ingot containing 30wt% magnesium.

According to the present invention, the magnesium ingots, zinc ingots and various intermediate alloy ingots are preferably processed through the steps of dividing, descaling, degreasing and drying. The magnesium ingot is preferably a pure magnesium ingot containing more than 99.9 wt% of magnesium, and the zinc ingot is preferably a pure zinc ingot containing more than 99.9 wt% of zinc.

The covering agent is a covering agent well known to those skilled in the art, preferably containing 30~40wt% of MgCl ₂ , preferably 35~40wt%, 15~25wt% of KCl or NaCl, preferably 18~22wt%, 15~ 25wt% of CaF or NaF, preferably 18-22wt% and the balance of BaCl ₂ . The quality of the covering agent is 2% to 5% of the total weight of the alloy raw material, preferably 2% to 3%. Its main function is to protect the melt from oxidation. At the same time, because magnesium is flammable, it can also be used as a fire extinguishing agent. use.

The refining agent is a refining agent well known to those skilled in the art, preferably comprising 50-60wt% of KCl or NaCl, preferably 52-56wt%, 15-20wt% of BaCl ₂ , preferably 16-19wt%, 20-30wt% % CaCl ₂ , preferably 22~26wt% and the balance of MgCO ₃ or Na ₂ CO ₃ . The quality of the refining agent is 2% to 5% of the total weight of the alloy raw material, preferably 2% to 3%, and its main function in the present invention is to improve the smelting quality of the alloy.

During the smelting process, the alloying elements are added in the form of an intermediate alloy, and the covering agent and refining agent are added at the same time, which can reduce the melting temperature of the alloy, remove inclusions, gases, etc., and improve the purity of the melt.

According to the present invention, the refining in step A is as follows: after adding the refining agent, stir for 10-15 minutes, preferably 12-14 minutes, blow in argon for 10-20 minutes, preferably 15-18 minutes, and heat up to 750°C-780°C , preferably 755°C~770°C, keep warm for 20~30min, preferably 25~30min, cool down to 730°C~750°C, preferably 730°C~740°C, keep warm for 10~20min, preferably 15~18min. The introduction of argon can eliminate other harmful gases in the melt such as chlorine and oxygen, and can also achieve the effect of stirring the melt to make the solute distribution in the melt more uniform and avoid casting defects such as segregation.

The step B specifically includes: performing slag removal treatment on the magnesium melt at 690°C-730°C, preferably 710°C-730°C, and casting it into a round rod through a water mold preheated to 200°C-300°C, The temperature is preferably 200° C. to 250° C. After turning, solution treatment, extrusion molding, and aging treatment, a deformed magnesium alloy is obtained.

The water mold can accelerate the cooling rate of the ingot and refine the grains, which is beneficial to large-scale industrial production.

The temperature of the solution treatment is 500°C~550°C, preferably 520°C~540°C, and the time is 2~32h, preferably 20~32h.

The extrusion molding conditions are 380°C-480°C, preferably 400°C-460°C, preheating for 30-120 minutes and then extrusion, preferably 60-100 minutes.

Solution treatment and preheating before extrusion molding are beneficial to the smooth progress of the extrusion process, avoiding the phenomenon of "not being squeezed", and reducing the extrusion temperature.

After the addition of zinc, a large number of elongated Mg ₁₂ YZn precipitates are formed at the grain boundaries in the alloy, which can prevent the grain boundaries from slipping under high temperature conditions and improve the high temperature stability of the alloy; and the precipitates are uniformly arranged along the extrusion direction, The crystal structure of wrought magnesium alloy is hexagonal, and the main slip system at room temperature is (0001) basal slip system. Therefore, the ordered Mg ₁₂ YZn precipitates can strengthen in the extrusion direction and hinder the basal plane. The mis-slip improves the mechanical properties of the alloy.

The aging treatment is preferably artificial aging, the aging temperature of the artificial aging is 185°C-250°C, preferably 200°C-240°C, and the aging time is 2-100h, preferably 60-80h.

After artificial aging, a large number of uniformly distributed nano-sized Mg-RE phases will be produced in the magnesium matrix, which can hinder the dislocation slip of the basal plane, reduce the deformation ability of the alloy, and improve the mechanical properties of the alloy. The present invention adopts multiple rare earth elements gadolinium, yttrium and neodymium as the added rare earth elements, and can utilize the interaction between the rare earth elements to reduce the solid solubility of these three elements in the magnesium matrix, improve the age hardening characteristics, and the aging sample at the peak The hardness reaches 130Hv, and can promote the formation of Mg-RE precipitates, and improve the mechanical properties of the alloy at room temperature and high temperature.

In order to further illustrate the present invention, a wrought magnesium alloy provided by the present invention and a preparation method thereof are described in detail below in conjunction with examples.

The reagents used in the following examples are all commercially available.

Example 1

1.1 Divide pure Mg ingots, pure Zn ingots, 20%Mg-Gd master alloys, 20%Mg-Y master alloys, 20%Mg-Nd master alloys and 30%Mg-Zr master alloys, remove scale and oil And drying, according to the element content Gd 10wt%, Y 4wt%, Zn 1wt%, Nd 0.5wt%, Zr 0.4wt%, the balance is the proportioning of Mg. Prepare covering agent: mix 40wt% MgCl ₂ , 20wt% KCl, 20wt% CaF and 20wt% BaCl ₂ to obtain covering agent; prepare refining agent: mix 54wt% KCl, 18wt% BaCl ₂ , 24wt% Cacl ₂ was mixed with 4wt% MgCO ₃ to obtain a refining agent.

1.2 Under the protection of 99% carbon dioxide and 1% sulfur hexafluoride mixed gas, add the covering agent prepared in 1.1 with 2wt% alloy raw materials, the pure Mg ingot and pure Zn ingot weighed in 1.1 into the melting furnace, Raise the temperature to 750°C, add the Mg-Gd master alloy and Mg-Nd master alloy weighed in 1.1, stir for 2 minutes, raise the temperature to 780°C, add the Mg-Y master alloy and Mg-Zr master alloy, stir for 2 minutes, and cool down to 750°C ℃, add the refining agent prepared in 1.1 of 2wt% alloy raw material, stir for 12 minutes, blow in argon gas for refining for 15 minutes, heat up to 750 ℃, keep it for 25 minutes, cool down to 730 ℃ for 15 minutes, and conduct the magnesium melt After removing the slag, it is cast into a round bar at 730°C through a water mold preheated to 200°C. After turning, it is solution treated at 535°C for 24 hours, and then extruded after preheating at 420°C for 60 minutes. The extrusion temperature is 420°C, and the extrusion ratio is 13, the extrusion rate is constant. Artificial aging treatment was carried out on the extruded alloy, the aging temperature was 200°C, and the aging time was 72h to obtain a deformed magnesium alloy, which contained Gd 10wt%, Y 4wt%, Zn 1wt%, Nd 0.5wt%, Zr 0.4wt%, The total amount of impurity elements Si, Fe, Cu and Ni is less than 0.02%, and the balance is Mg.

The mechanical properties of the deformed magnesium alloy obtained in 1.2 were tested, and the test results were obtained, as shown in Table 1.

Room temperature and high temperature mechanical properties of deformed magnesium alloy in Table 1 Example 1

Example 2

2.1 Divide pure Mg ingots, pure Zn ingots, 20%Mg-Gd master alloys, 20%Mg-Y master alloys, 20%Mg-Nd master alloys and 30%Mg-Zr master alloys, remove scale and oil And drying, according to the element content Gd 11wt%, Y 5wt%, Zn 1.5wt%, Nd 1wt%, Zr 0.8wt%, the balance is the ratio of Mg. Prepare covering agent: mix 40wt% MgCl ₂ , 20wt% KCl, 20wt% CaF and 20wt% BaCl ₂ to obtain covering agent; prepare refining agent: mix 54wt% KCl, 18wt% BaCl ₂ , 24wt% Cacl ₂ was mixed with 4wt% MgCO ₃ to obtain a refining agent.

2.2 Under the protection of the mixed gas of 99% carbon dioxide and 1% sulfur hexafluoride, add the covering agent prepared in 2.1 with 2wt% alloy raw materials, the pure Mg ingot and the pure Zn ingot weighed in 2.1 into the melting furnace, Raise the temperature to 730°C, add the Mg-Gd master alloy and Mg-Nd master alloy weighed in 2.1, stir for 2 minutes, raise the temperature to 780°C, add the Mg-Y master alloy and Mg-Zr master alloy, stir for 2 minutes, and cool down to 730°C ℃, add the refining agent prepared in 2.1 of 2wt% alloy raw material, stir for 12 minutes, blow in argon gas for 15 minutes, heat up to 780 ℃, keep the temperature for 25 minutes, cool down to 750 ℃ for 15 minutes, and conduct the magnesium melt After removing the slag, it is cast into a round bar at 720°C through a water mold preheated to 200°C. After turning, it is solution treated at 535°C for 24 hours, and then extruded after preheating at 410°C for 60 minutes. The extrusion temperature is 410°C, and the extrusion ratio is 13, the extrusion rate is constant. The extruded alloy was subjected to artificial aging treatment, the aging temperature was 200°C, and the aging time was 72h to obtain a deformed magnesium alloy, including Gd 11wt%, Y 5wt%, Zn 1.5wt%, Nd 1wt%, Zr 0.8wt%, The total amount of impurity elements Si, Fe, Cu and Ni is less than 0.02%, and the balance is Mg.

The mechanical properties of the deformed magnesium alloy obtained in 2.2 were tested, and the test results were obtained, as shown in Table 2.

Room temperature and high temperature mechanical properties of deformed magnesium alloy in Table 2 Example 2

The deformed magnesium alloy obtained in 2.2 was analyzed by scanning electron microscopy, and the metallographic structure diagram of the extruded state was obtained, as shown in Figure 1. In the figure, A is the elongated Mg ₁₂ YZn precipitate, and B is the Mg-RE precipitate (Mg ₅ Gd).

The deformed magnesium alloy obtained in 2.2 was analyzed by transmission electron microscope, and its transmission electron microscope microstructure was obtained, as shown in Fig. 2 . In the figure, A is the elongated Mg ₁₂ YZn precipitate, and B is the Mg-RE precipitate (Mg ₅ Gd).

Example 3

3.1 Divide pure Mg ingots, pure Zn ingots, 20%Mg-Gd master alloys, 20%Mg-Y master alloys, 20%Mg-Nd master alloys and 30%Mg-Zr master alloys, remove scale and oil And drying, according to the element content Gd 10wt%, Y 4wt%, Zn 0.5wt%, Nd 2wt%, Zr 0.5wt%, the balance is the proportioning of Mg. Prepare covering agent: mix 40wt% MgCl ₂ , 20wt% KCl, 20wt% CaF and 20wt% BaCl ₂ to obtain covering agent; prepare refining agent: mix 54wt% KCl, 18wt% BaCl ₂ , 24wt% Cacl ₂ was mixed with 4wt% MgCO ₃ to obtain a refining agent.

3.2 Under the protection of the mixed gas of 99% carbon dioxide and 1% sulfur hexafluoride, add the covering agent prepared in 3.1 with 2wt% alloy raw material, the pure Mg ingot and the pure Zn ingot weighed in 3.1 into the melting furnace, Raise the temperature to 730°C, add the Mg-Gd master alloy and Mg-Nd master alloy weighed in 3.1, stir for 2 minutes, raise the temperature to 780°C, add the Mg-Y master alloy and Mg-Zr master alloy, stir for 2 minutes, and cool down to 730°C ℃, add the refining agent prepared in 3.1 of 2wt% alloy raw material, stir for 12 minutes, blow in argon gas for 15 minutes, heat up to 750 ℃, keep the temperature for 25 minutes, cool down to 730 ℃ and keep the temperature for 15 minutes, and conduct the magnesium melt After removing the slag, it is cast into a round bar at 690°C through a water mold preheated to 300°C. After turning, it is solution treated at 550°C for 24 hours, and then extruded after preheating at 450°C for 60 minutes. The extrusion temperature is 450°C and the extrusion ratio is 33, and the extrusion rate is constant. The extruded alloy was subjected to artificial aging treatment, the aging temperature was 200°C, and the aging time was 72h to obtain a deformed magnesium alloy, including Gd 10wt%, Y 4wt%, Zn 0.5wt%, Nd 2wt%, Zr 0.5wt%, The total amount of impurity elements Si, Fe, Cu and Ni is less than 0.02%, and the balance is Mg.

The mechanical properties of the deformed magnesium alloy obtained in 3.2 were tested, and the test results were obtained, as shown in Table 3.

Room temperature and high temperature mechanical properties of deformed magnesium alloy in Table 3 Example 3

Example 4

4.1 Divide pure Mg ingots, pure Zn ingots, 20%Mg-Gd master alloys, 20%Mg-Y master alloys, 20%Mg-Nd master alloys and 30%Mg-Zr master alloys, remove scale and oil And drying, according to the element content Gd 12wt%, Y 3wt%, Zn 2wt%, Nd 3wt%, Zr 0.6wt%, the balance is the ratio of Mg. Prepare covering agent: mix 40wt% MgCl ₂ , 20wt% KCl, 20wt% CaF and 20wt% BaCl ₂ to obtain covering agent; prepare refining agent: mix 54wt% KCl, 18wt% BaCl ₂ , 24wt% Cacl ₂ was mixed with 4wt% MgCO ₃ to obtain a refining agent.

4.2 Under the protection of 99% carbon dioxide and 1% sulfur hexafluoride mixed gas, add the covering agent prepared in 4.1 with 2wt% alloy raw materials, the pure Mg ingot and pure Zn ingot weighed in 4.1 into the melting furnace, Raise the temperature to 730°C, add the Mg-Gd master alloy and Mg-Nd master alloy weighed in 4.1, stir for 2 minutes, raise the temperature to 780°C, add the Mg-Y master alloy and Mg-Zr master alloy, stir for 2 minutes, and cool down to 730°C ℃, add the refining agent prepared in 4.1 of 2wt% alloy raw material, stir for 12 minutes, blow in argon gas for refining for 15 minutes, heat up to 780 ℃, keep it for 25 minutes, cool down to 730 ℃ for 15 minutes, and conduct the magnesium melt After removing the slag, it is cast into a round bar at 690°C through a water mold preheated to 200°C. After turning, it is solution treated at 500°C for 24 hours, and then extruded after preheating at 430°C for 60 minutes. The extrusion temperature is 430°C, and the extrusion ratio is 33, and the extrusion rate is constant. The extruded alloy was subjected to artificial aging treatment, the aging temperature was 200°C, and the aging time was 72h to obtain a deformed magnesium alloy containing Gd 12wt%, Y 3wt%, Zn 2wt%, Nd 3wt%, Zr 0.6wt%, impurities The total amount of elements Si, Fe, Cu and Ni is less than 0.02%, and the balance is Mg.

The mechanical properties of the deformed magnesium alloy obtained in 4.2 were tested, and the test results were obtained, as shown in Table 4.

Room temperature and high temperature mechanical properties of deformed magnesium alloy in Table 4 Example 4

comparative example

Table 5 Mechanical properties of WE54 from Elektron, UK

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. a wrought magnesium alloys is characterized in that, comprising: the neodymium of 0.1wt%10wt%, the gadolinium of 10wt% ~ 12wt%, the yttrium of 3wt% ~ 5wt%, the zinc of 0.5wt% ~ 2wt%, the zirconium of 0.3wt% ~ 0.8wt%, the magnesium of surplus and unavoidable impurities.

2. the preparation method of a wrought magnesium alloys is characterized in that, may further comprise the steps:

A) molten alloyizatioies carry out in magnesium ingot, zinc ingot metal, gadolinium source, neodymium source, yttrium source and zirconium source; Obtain the magnesium melt after the refining, said magnesium melt comprises the neodymium of 0.1wt%10wt%, the gadolinium of 10wt% ~ 12wt%; The yttrium of 3wt% ~ 5wt%; The zinc of 0.5wt% ~ 2wt%, the zirconium of 0.3wt% ~ 0.8wt%, the magnesium of surplus and unavoidable impurities;

B) with said magnesium melt casting, after the extruding, obtain wrought magnesium alloys.

3. preparation method according to claim 2 is characterized in that, said gadolinium source is gadolinium ingot and/or magnesium gadolinium intermediate alloy ingot.

4. preparation method according to claim 2 is characterized in that, said neodymium source is neodymium ingot and/or magnesium neodymium intermediate alloy ingot.

5. preparation method according to claim 2 is characterized in that, said yttrium source is yttrium ingot and/or magnesium yttrium intermediate alloy ingot.

6. preparation method according to claim 2 is characterized in that, said zirconium source is zirconium ingot and/or magnesium zirconium intermediate alloy ingot.

7. preparation method according to claim 2 is characterized in that, said step B is specially:

With the casting of said magnesium melt, solution treatment, extruding, carry out ageing treatment after, obtain wrought magnesium alloys.

8. preparation method according to claim 2 is characterized in that, said steps A is specially:

Under protective atmosphere, magnesium ingot, zinc ingot metal and insulating covering agent are added to smelting furnace, be warming up to 730 ℃ ~ 750 ℃, add gadolinium source and neodymium source, continue to be warming up to 760 ℃ ~ 780 ℃, obtain the magnesium melt after adding yttrium source, zirconium source and the refining agent refining; Said magnesium melt comprises the neodymium of 0.1wt% ~ 10wt%, the gadolinium of 10wt% ~ 12wt%, the yttrium of 3wt% ~ 5wt%, the zinc of 0.5wt% ~ 2wt%, the zirconium of 0.3wt% ~ 0.8wt%, the magnesium of surplus and unavoidable impurities.

9. preparation method according to claim 8 is characterized in that said insulating covering agent comprises the MgCl of 30 ~ 40wt% ₂, the KCl/NaCl of 15 ~ 25wt%, the CaF/NaF of 15 ~ 25wt% and the BaCl of surplus ₂

10. preparation method according to claim 8 is characterized in that said refining agent comprises the KCl/NaCl of 50 ~ 60wt%, the BaCl of 15 ~ 20wt% ₂, the CaCl of 20 ~ 30wt% ₂MgCO with surplus ₃/ Na ₂CO ₃

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