High-strength corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy and preparation process thereof

Abstract

The invention discloses a high-strength corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy and a high-temperature extrusion forming process thereof, and relates to the technical field of non-ferrous metal materials and processing thereof.The magnesium alloy comprises, by mass, 8% of Gd, 4% of Y, 1.2% of Zn, 0.3% of Zr, 0.2-0.5% of Al and the balance Mg and inevitable impurities. The high-temperature extrusion forming process comprises the following steps of preparation of a high-quality casting blank through a semi-continuous casting technology, high-temperature long-time solution treatment, high-temperature reverse extrusion and isothermal aging treatment. Wherein high-temperature backward extrusion is carried out at 400 DEG C, the extrusion ratio is about 7, and quenching is carried out in cold water after extrusion; test results show that the yield strength of the high-strength corrosion-resistant rare earth magnesium alloy prepared through the high-temperature backward extrusion forming process is larger than or equal to 328 MPa, the tensile strength is larger than or equal to 372 MPa, and the ductility is larger than or equal to 19.0%; and the high-strength corrosion-resistant magnesium extrusion rod is successfully prepared and has important significance in promoting the application of magnesium alloy in the high-tech fields of aerospace, national defense and military industry and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-ferrous metal structural materials and their processing, and particularly relates to a design and preparation method for a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy. Background Art

[0002] As the lightest metal structural material at present, magnesium alloys have high specific strength and specific stiffness, good cutting performance, electromagnetic shielding performance, and damping and shock absorption performance. Moreover, they are rich in resources and easy to recycle. Therefore, they have broad application prospects in the fields of aerospace, automotive, consumer electronics, military, etc. However, problems such as low absolute strength and poor high-temperature performance of magnesium alloys severely limit their applications in high-tech fields, especially in high-temperature service environments such as aerospace engines and missile casings. At present, to solve the technical problems of low strength and poor heat resistance of magnesium alloys, the main solutions are as follows: (1) Optimize the alloy composition design and improve the strength and heat resistance of the alloy by adding rare earth elements; (2) Adopt advanced plastic processing technologies such as isothermal forging and hot extrusion to refine grains and improve the comprehensive performance of the alloy. A large number of studies have shown that Mg-Gd-Y-Zr series magnesium alloys have excellent mechanical properties at room temperature and high temperature, and are a high-strength and corrosion-resistant magnesium alloy system with great development potential. Among them, the addition of Gd and Y elements can form stable precipitation phases, significantly improving the strength and heat resistance of the alloy; the addition of Zr element can refine grains and improve the strength and toughness of the alloy. However, traditional Mg-Gd-Y-Zr series magnesium alloys still have some deficiencies: (1) The addition amounts of Gd and Y elements are relatively high, resulting in an increase in alloy cost; (2) The processing temperature window of the alloy is relatively narrow, and the plastic processing is difficult; (3) The coordinated improvement of the strength and corrosion resistance of the alloy still needs to be further enhanced.

[0003] To solve the above problems, this patent adds a trace amount of Al element to the Mg-Gd-Y-Zr series magnesium alloy to completely replace / partially replace the Zn element. The addition of a trace amount of Al (0.2%) can form the long-period ordered stacking structure (LPSO) phase in the Mg-Gd-Y-Zr alloy. This high-hardness micron-scale second phase is beneficial to strengthening the strength of the magnesium matrix and reducing the micro-galvanic corrosion between the magnesium matrix and the second phase. Therefore, the addition of a trace amount of Al (0.2%) can improve the mechanical and corrosion resistance of the Mg-Gd-Y-Zn-Zr-Al alloy, thereby enhancing the comprehensive performance of the Al-containing magnesium rare earth alloy. Summary of the Invention

[0004] Aiming at the insufficient corrosion resistance of existing Mg-Gd-Y-Zn-Zr, the present invention provides a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy with trace addition of Al element and its preparation method, preparing a wrought magnesium alloy with both anti-corrosion and mechanical properties; making full use of the characteristics of high solid solubility and strong precipitation hardening of rare earth element Gd in magnesium, and the microalloying of Al element. Since the Al element completely replaces / partially replaces the Zn element in the long-period ordered stacking structure (LPSO) phase of traditional rare earth magnesium alloys, and compared with traditional rare earth magnesium alloys, because it changes the phase morphology and reduces its content, it reduces the micro-galvanic corrosion in the magnesium matrix, while refining the recrystallized grains and promoting the precipitation of high-hardness nano-phases during the subsequent aging process, improving the extrusion forming performance of the alloy, and successfully preparing a high-strength and corrosion-resistant magnesium extrusion rod, which is of great significance for promoting the application of magnesium alloys in high-tech fields such as aerospace and national defense.

[0005] To achieve the above technical objectives, the technical solutions adopted by the present invention are as follows.

[0006] A high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy, the components of which are by mass percentage: Gd: 8wt.%, Y: 4 wt.%, Zn: 1.2%, Zr: 0.3wt.%, Al: 0.2~0.5wt.%, and the balance is Mg and unavoidable impurities.

[0007] The test results show that: the yield strength of a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy is: 310~328MPa, the ultimate tensile strength is: 352~372 MPa, and the elongation is: 11.8~19.0%.

[0008] The test results show that: the hydrogen evolution corrosion rate is 0.24~0.5mm / y, and the weight loss corrosion rate is 0.36~0.75mm / y.

[0009] A preparation method of a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy specifically includes the following steps: Step 1, material preparation: Weigh magnesium ingots, aluminum ingots, and Mg-Gd, Mg-Y, Mg-Zn, Mg-Zr master alloys according to the mass percentage of the components of the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy; Step 2, ingot melting: Put magnesium ingots and aluminum ingots into an induction melting furnace, heat to 715 - 725 °C under a protective atmosphere, keep warm for 8 - 12 min after complete melting; under a protective atmosphere, add Mg-Gd, Mg-Y, Mg-Zn master alloys, keep warm for 8 - 12 min after complete melting into a melt with stirring; heat up to 745 - 755 °C, then add Mg-Zr master alloy, keep warm for 20 - 30 min after complete melting into a melt with stirring; Control the temperature of the alloy melt at 700 - 750 °C and let it stand for 10 - 20 min, remove the scum on the surface, and cast it into an iron mold preheated to 200 - 350 °C to obtain a Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot; Step 3, homogenization treatment: Isolate the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot from air, heat to 500 - 520 °C, keep warm for 8 - 12 hours, and obtain a homogenized Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot after water quenching; Step 4, backward extrusion: The homogenized Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot is preheated at 300 - 400 °C for 15 min, and backward extrusion is carried out at 300 - 400 °C, the extrusion ratio is (5 - 20):1, and the extrusion speed is 0.01 - 2 m / min to obtain a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy.

[0010] Preferably, the weight percentages of each metal in the Mg-Gd, Mg-Y, Mg-Zn and Mg-Zr master alloys are Mg-30Gd, Mg-30Y, Mg-30Zn and Mg-30Zr respectively.

[0011] Preferably, in the preparation method of the high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy, in step 2, the protective atmosphere is a mixed gas of SF6 and CO2.

[0012] Preferably, in the preparation method of the high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy, in step 3, the method for isolating the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot from air is: covering with graphite powder or in a vacuum environment or under a protective gas to isolate air, wherein the protective gas is argon.

[0013] The beneficial effects obtained by the technical solution of the present invention are: The high-strength and corrosion-resistant rare-earth magnesium alloy of the present invention adds an appropriate amount of Al element to the magnesium-rare-earth alloy, which can not only improve the corrosion resistance of the alloy, but also form the LPSO phase, thereby improving the mechanical properties of the alloy. It can provide a new research idea for the development of high-strength stainless magnesium alloys. Using trace Al as the alloying element and selecting the common Mg-Gd-Y-Zr magnesium alloy system. Adding Gd element under the alloy system can form a multi-phase solid solution structure after high-temperature solution treatment, which is beneficial to hot extrusion forming.

[0014] Since Gd, as a heavy rare-earth element, exhibits many modification properties similar to those of the rare-earth element Y in magnesium alloys, such as having a high solid solubility (>8%) in magnesium alloys, which is significantly different from the light rare-earth elements La, Ce, etc. At the same time, Al can form rod-shaped LPSO phases without zinc. Compared with traditional Zn-containing Mg-RE alloys, this high-hardness micron-sized second phase is beneficial to strengthening the strength of the magnesium matrix and reducing the micro-galvanic corrosion between the magnesium matrix and the second phase. Therefore, the addition of trace Al (0.2%) can improve the mechanical and corrosion-resistant properties of Mg-Gd-Y-Zn-Zr-Al alloys, thereby enhancing the comprehensive performance of Al-containing magnesium-rare-earth alloys. Brief Description of the Drawings

[0015] Figure 1-2 Microstructure (SEM, OM) of the high-strength and corrosion-resistant extruded magnesium alloy prepared in Example 3 of the present invention.

[0016] Figure 3 Corrosion surface photos of the high-strength and corrosion-resistant extruded magnesium alloy prepared in Example 3 of the present invention after soaking in 3.5%wt sodium chloride solution for 1 hour, 1 day, and 3 days.

[0017] Figure 4 Corrosion micro-morphology of the high-strength and corrosion-resistant extruded magnesium alloy prepared in Example 3 of the present invention after soaking in 3.5%wt sodium chloride solution for 3 days.

[0018] Figure 5 Stress-strain curve of the high-strength and corrosion-resistant extruded magnesium alloy prepared in Example 3 of the present invention.

[0019] Figure 6 EIS impedance curve of the high-strength and corrosion-resistant extruded magnesium alloy prepared in Example 3 of the present invention after soaking in 3.5%wt sodium chloride solution for 1 hour. Detailed Description of the Invention

[0020] Example 1 High-strength and corrosion-resistant Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.2Al wrought magnesium alloy, the components are by mass percentage: 8.0wt.% Gd; 4.0wt.% Y; Zn: 1.2%; 0.3wt.% Zr; 0.2wt.% Al, and the balance is Mg and unavoidable impurity elements.

[0021] The preparation method of the high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy in this embodiment is as follows: Step 1, material preparation: Weigh magnesium ingots, aluminum ingots, and Mg-30Gd, Mg-30Y, Mg-30Zn, and Mg-30Zr master alloys according to the mass percentages of the components of the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy. Step 2, ingot melting: Put the magnesium ingots and aluminum ingots into an induction melting furnace, and under the protective atmosphere of a mixed gas of SF6 and CO2, heat to 715~725°C, keep warm for 8~12 minutes after complete melting; under the protective atmosphere, add Mg-30Gd, Mg-30Y, and Mg-30Zn master alloys, stir and keep warm for 8~12 minutes after complete melting into a melt; raise the temperature to 745~755°C, then add Mg-30Zr master alloy, stir and keep warm for 20~30 minutes after complete melting into a melt. Control the temperature of the alloy melt at 700~750°C and let it stand for 10~20 minutes, remove the floating slag on the surface, and pour it into an iron mold preheated to 200~350°C to obtain a Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.2Al wrought magnesium alloy ingot. Step 3, homogenization treatment: Cover the Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.2Al wrought magnesium alloy ingot with graphite powder to isolate air, and under the protective gas of argon, heat to 520°C for homogenization treatment for 8 hours, and obtain a homogenized Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.2Al wrought magnesium alloy ingot after water quenching.

[0022] Step 4, backward extrusion: For the homogenized Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.2Al wrought magnesium alloy ingot, turn off the surface oxide scale and then preheat at 400°C, apply graphite lubrication and then perform backward extrusion at 400°C; the extrusion ratio is 7:1, and the extrusion speed is 0.3m / min to obtain a high-strength and corrosion-resistant Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.2Al wrought magnesium alloy rod with a diameter of 18mm.

[0023] The mechanical property test of the Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.2Al wrought rare earth magnesium alloy in this example shows that: the ultimate tensile strength is 368 MPa, and the yield strength is 310 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 0.24 mm / y, and the weight loss corrosion rate is 0.36 mm / y.

[0024] Example 2 The difference between this example and Example 1 is that: for the high-strength and corrosion-resistant Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.3Al wrought magnesium alloy, the components are by mass percentage: 8.0 wt.% Gd; 4.0 wt.% Y; 1.2 wt.% Zn; 0.3 wt.% Zr; 0.3 wt.% Al, and the balance is Mg and inevitable impurity elements.

[0025] The mechanical property test of the Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.3Al wrought rare earth magnesium alloy in this example shows that: the ultimate tensile strength is 369 MPa, and the yield strength is 314 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 0.35 mm / y, and the weight loss corrosion rate is 0.50 mm / y.

[0026] Example 3 The difference between this example and Example 1 is that: for the high-strength and corrosion-resistant Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.5Al wrought magnesium alloy, the components are by mass percentage: 8.0 wt.% Gd; 4.0 wt.% Y; 1.2 wt.% Zn; 0.3 wt.% Zr; 0.5 wt.% Al, and the balance is Mg and inevitable impurity elements.

[0027] The mechanical property test of the Mg-8.0Gd-4.0Y-1.2Zn-0.3Zr-0.5Al wrought rare earth magnesium alloy in this example shows that: the ultimate tensile strength is 372 MPa, and the yield strength is 320 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 0.50 mm / y, and the weight loss corrosion rate is 0.75 mm / y.

[0028] Example 4 The difference between this example and Example 1 is that: for the high-strength and corrosion-resistant Mg-8.0Gd-4.0Y-0.3Zr-0.2Al wrought magnesium alloy, the components are by mass percentage: Gd: 8 wt.%; Y: 4 wt.%; Zr: 0.3 wt.%; Al: 0.2 wt.%, and the balance is Mg and inevitable impurity elements.

[0029] The difference between the preparation method of this example and that of Example 1 is as follows: For the Mg-Gd-Y-Zr-Al wrought magnesium alloy, the component mass percentages are used to weigh ingots of magnesium, aluminum, and the master alloys of Mg-30Gd, Mg-30Y, and Mg-30Zr. The difference in ingot melting is as follows: The ingots of magnesium and aluminum are put into an induction melting furnace and heated to 715 - 725 °C under a protective atmosphere of a mixed gas of SF6 and CO2. After complete melting, it is held for 8 - 12 min. Under the protective atmosphere, the master alloys of Mg-30Gd and Mg-30Y are added. After complete melting into a melt, it is stirred and held for 8 - 12 min. The temperature is raised to 745 - 755 °C, and then the master alloy of Mg-30Zr is added. After complete melting into a melt, it is stirred and held for 20 - 30 min. The mechanical property test of the Mg-8.0Gd-4.0Y-0.3Zr-0.2Al wrought rare-earth magnesium alloy in this example shows that: the ultimate tensile strength is 371 MPa, and the yield strength is 321 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 0.29 mm / y, and the weight loss corrosion rate is 0.44 mm / y.

[0030] Example 5 The difference between this example and Example 4 is as follows: For the high-strength and corrosion-resistant Mg-8.0Gd-4.0Y-0.3Zr-0.3Al wrought magnesium alloy, the components by mass percentage are: Gd: 8 wt.%; Y: 4 wt.%; Zr: 0.3 wt.%; Al: 0.3 wt.%, and the balance is Mg and unavoidable impurity elements.

[0031] The mechanical property test of the Mg-8.0Gd-4.0Y-0.3Zr-0.3Al wrought rare-earth magnesium alloy in this example shows that: the ultimate tensile strength is 366 MPa, and the yield strength is 321 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 0.28 mm / y, and the weight loss corrosion rate is 0.47 mm / y.

[0032] Example 6 The difference between this example and Example 4 is as follows: For the high-strength and corrosion-resistant Mg-8.0Gd-4.0Y-0.3Zr-0.5Al wrought magnesium alloy, the components by mass percentage are: Gd: 8 wt.%; Y: 4 wt.%; Zr: 0.3 wt.%; Al: 0.5 wt.%, and the balance is Mg and unavoidable impurity elements.

[0033] The mechanical property test of the Mg-8.0Gd-4.0Y-0.3Zr-0.5Al wrought rare earth magnesium alloy in this embodiment shows that: the ultimate tensile strength is 352 MPa, and the yield strength is 328 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 0.33 mm / y, and the weight loss corrosion rate is 0.51 mm / y.

[0034] Comparative Example 1 The difference between this comparative example and Example 1 is as follows: for a high-strength and corrosion-resistant Mg-9Gd-4Y-1.4Zn-0.3Zr wrought magnesium alloy, it is characterized in that: Gd: 9 wt.%, Y: 4 wt.%, Zn: 1.4%, Zr: 0.3 wt.%.

[0035] The difference between the preparation method of this comparative example and that of Example 1 is as follows: weigh magnesium ingots and Mg-30Gd, Mg-30Y, Mg-30Zn, and Mg-30Zr master alloys according to the mass percentages of the components of the Mg-9Gd-4Y-1.4Zn-0.3Zr wrought magnesium alloy. The difference in the ingot melting is as follows: put the magnesium ingots into an induction melting furnace, under the protective atmosphere of a mixed gas of SF6 and CO2, heat to 715 - 725 °C, keep it warm for 8 - 12 min after complete melting; under the protective atmosphere, add Mg-30Gd, Mg-30Y, and Mg-30Zn master alloys, keep it warm for 8 - 12 min after complete melting into a melt and stirring; raise the temperature to 745 - 755 °C, then add the Mg-30Zr master alloy, keep it warm for 20 - 30 min after complete melting into a melt and stirring. The mechanical property test of the Mg-9.0Gd-4.0Y-1.4Zn-0.3Zr wrought rare earth magnesium alloy in this comparative example shows that: the ultimate tensile strength is 358 MPa, and the yield strength is 277 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 1.05 mm / y, and the weight loss corrosion rate is 1.29 mm / y.

[0036] Comparative Example 2 The difference between this comparative example and Comparative Example 1 is as follows: for a high-strength and corrosion-resistant Mg-9.0Gd-4.0Y-1.2Zn-0.3Zr wrought magnesium alloy, it is characterized in that: Gd: 9 wt.%, Y: 4 wt.%, Zn: 1.2%, Zr: 0.3 wt.%.

[0037] The mechanical property test of the Mg-9.0Gd-4.0Y-1.2Zn-0.3Zr wrought rare earth magnesium alloy in this comparative example shows that: the ultimate tensile strength is 370 MPa, and the yield strength is 286 MPa; the corrosion property test shows that: the hydrogen evolution corrosion rate is 2.56 mm / y, and the weight loss corrosion rate is 3.05 mm / y.

[0038] According to the standard of GBT-228.1-2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", the room temperature mechanical properties of the Mg-RE deformed magnesium alloy bars prepared in the examples and comparative examples of the present invention were tested. The tensile direction was parallel to the extrusion direction, and the test results are listed in Table 1.

[0039] Table 1. Room temperature mechanical properties and corrosion properties of Mg-RE deformed magnesium alloy Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy, characterized in that, The components are by mass percentage: Gd: 8 wt.%, Y: 4 wt.%, Zn: 1.2%, Zr: 0.3 wt.%, Al: 0.2 - 0.5 wt.%, and the balance is Mg and inevitable impurities.

2. A high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to claim 1, characterized in that, Al: 0.2 wt.%.

3. A high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to claim 1, characterized in that, Al: 0.3 wt.%.

4. A high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to claim 1, characterized in that, Al: 0.5 wt.%.

5. A high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to any one of claims 1-4, characterized in that The yield strength of the alloy is: 310 - 328 MPa, the ultimate tensile strength is: 352 - 372 MPa, and the elongation is: 11.8 - 19.0%.

6. A high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to any one of claims 1-4, characterized in that, The hydrogen evolution corrosion rate is 0.24 - 0.5 mm / y, and the weight loss corrosion rate is 0.36 - 0.75 mm / y.

7. The preparation method of a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to claim 1, characterized in that Specifically, it includes the following steps: Step 1, material preparation: Weigh magnesium ingots, aluminum ingots, and Mg-Gd, Mg-Y, Mg-Zn, Mg-Zr master alloys according to the mass percentages of the components of the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy. Step 2, ingot melting: Put the magnesium ingots and aluminum ingots into an induction melting furnace, heat to 715 - 725 °C under a protective atmosphere, keep warm for 8 - 12 min after complete melting; under a protective atmosphere, add Mg-Gd, Mg-Y, Mg-Zn master alloys, keep warm for 8 - 12 min after complete melting into a melt; heat up to 745 - 755 °C, then add Mg-Zr master alloy, keep warm for 20 - 30 min after complete melting into a melt. Control the temperature of the alloy melt at 700 - 750 °C and let it stand for 10 - 20 min, remove the scum on the surface, and pour it into an iron mold preheated to 200 - 350 °C to obtain an Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot. Step 3, homogenization treatment: Isolate the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot from air, heat to 500 - 520 °C, keep warm for 8 - 12 hours, and obtain a homogenized Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot after water quenching.

8. The preparation method of a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to claim 7, characterized in that, Conduct reverse extrusion treatment on the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot obtained after homogenization treatment; for the homogenized Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot, turn off the surface oxide scale and then preheat it at 400 °C, apply graphite lubrication and then conduct reverse extrusion at 400 °C; the extrusion ratio is 7:1, and the extrusion speed is 0.3 m / min to obtain a high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy bar.

9. A high-strength and corrosion-resistant Mg-RE alloy according to claim 8, wherein the weight percentages of the respective metals in the Mg-Gd, Mg-Y, Mg-Zn, and Mg-Zr master alloys are Mg-30Gd, Mg-30Y, Mg-30Zn, and Mg-30Zr; in the step 2, the protective atmosphere is a mixed gas of SF6 and CO2; in the step 3, the method for isolating the Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy ingot from air is: covering it with graphite powder or in a vacuum environment or under a protective gas to isolate air, wherein, The protective gas is argon.

10. The preparation method of the high-strength and corrosion-resistant Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy according to claim 8, wherein, The Mg-Gd-Y-Zn-Zr-Al wrought magnesium alloy is an alloy bar, and the diameter of the bar is 18 mm.

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