Preparation and heat treatment strengthening method of high-performance Mg-Al-Sn-Zn-Ca magnesium alloy
By preparing Mg-Al-Sn-Zn-Ca magnesium alloys and using the T6 heat treatment process, the precision and performance issues in the magnesium alloy casting process have been solved, resulting in high-strength, high-toughness, and low-cost magnesium alloy materials, providing a reliable solution for high-end manufacturing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-03-27
AI Technical Summary
Existing traditional magnesium alloys suffer from problems such as low dimensional accuracy, poor surface quality, and unstable mechanical properties during the casting process. Furthermore, the heat treatment process is time-consuming and energy-intensive, which limits their application in high-end manufacturing fields.
The preparation method of Mg-Al-Sn-Zn-Ca magnesium alloy is adopted. By precisely designing the elemental composition and multi-component synergistic alloying, combined with semi-solid thixotropic injection casting and T6 heat treatment process, including low temperature solution treatment, room temperature water cooling, low temperature aging and air cooling, the melting and casting process is optimized to control the distribution and microstructure of precipitated phases.
It significantly improves the mechanical properties of magnesium alloys, achieving high strength, toughness, and elongation, while reducing costs and expanding their application potential in high-end manufacturing.
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Figure CN121737500A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal material processing technology, specifically a method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy. Background Technology
[0002] As one of the most promising green materials of the 21st century, magnesium alloy is the lightest metallic structural material in practical applications, with a density of approximately 1.74 g / cm³. 3 With a strength only 2 / 3 that of aluminum alloys and 1 / 4 that of steel, magnesium alloys possess high specific strength, specific stiffness, excellent electromagnetic interference resistance and vibration reduction performance, as well as good biocompatibility. They have broad application prospects in structural components for aerospace equipment, new energy vehicles, 3C (computer, communication, and consumer electronics) products, and medical devices. Especially under the current "dual-carbon" strategy, lightweighting has become a key path to energy conservation and emission reduction. Magnesium alloys, due to their outstanding lightweighting potential, have attracted much attention from researchers and are gradually becoming the preferred material in many high-end manufacturing fields.
[0003] However, existing traditional magnesium alloy casting processes face numerous challenges, including low dimensional accuracy, poor surface quality, and unstable mechanical properties. These defects severely limit the application potential of magnesium alloys in high-end manufacturing. Semi-solid thixotropic injection casting, as a typical near-net-shape forming process, offers significant advantages such as low forming temperature, long mold life, stable filling, minimal shrinkage cavities and porosity, high dimensional accuracy, and the ability to rapidly manufacture thin-walled complex parts in a single operation. Furthermore, magnesium alloys typically require complex heat treatment processes to improve their mechanical properties; these processes are not only time-consuming and energy-intensive but also costly. Therefore, there is an urgent need to develop a novel integrated strengthening method for magnesium alloy preparation and T6 heat treatment suitable for semi-solid thixotropic injection casting. This method should not only exhibit excellent fluidity and formability during semi-solid thixotropic injection casting but also achieve comprehensive mechanical properties such as high strength and toughness, high elongation, and excellent dimensional stability after heat treatment. This is one of the key research focuses and challenges currently facing the industry. Summary of the Invention
[0004] The present invention aims to solve the technical problems of low mechanical properties and inability to balance strength and plasticity in current semi-solid thixotropic injection-cast magnesium alloys, and provides a method for preparing and heat-treating to strengthen high-performance Mg-Al-Sn-Zn-Ca magnesium alloys.
[0005] The preparation and heat treatment strengthening method of the high-performance Mg-Al-Sn-Zn-Ca magnesium alloy of the present invention is carried out according to the following steps:
[0006] I. Preparation process of Mg-Al-Sn-Zn-Ca magnesium alloy:
[0007] ① Weigh out pure Mg blocks, pure Al blocks, pure Sn granules, pure Zn blocks and Mg-30wt.%Ca master alloy according to the mass percentage of each element in the magnesium alloy. Remove the dust and oil from the surface of the above raw materials using an angle grinder, and then put them into a forced-air drying oven for drying.
[0008] The magnesium alloy comprises the following elements by mass percentage: Al content is 8.4%~9.6%, Sn content is 1.2%~2.4%, Zn content is 0.6%~1.2%, Ca content is 0.2%~0.8%, impurities Si+Fe+C≤0.015%, and Mg is the balance.
[0009] ② Melting: The dried pure Mg blocks are placed into a crucible and then sent into a melting furnace. The furnace is heated to 520℃~530℃, and a mixture of CO2 and SF6 protective gas is introduced. Then, the temperature is raised to 675℃~685℃ at a heating rate of 7.5℃ / min~10.5℃ / min and held for 80min~100min. After the pure Mg is completely melted into liquid, the pure Al blocks dried in step ①, Mg-30wt.%Ca master alloy, pure Sn blocks and pure Zn blocks are added to the crucible in sequence at intervals of 1min~3min. The holding time after adding the pure Zn blocks is 10min~30min.
[0010] ③ The process of stirring, slag removal, and air refining is carried out in sequence, and then the melt temperature is raised to 685℃~700℃ and held for 3min~5min;
[0011] ④ Pouring: Pour the solution in the crucible into a gravity casting mold preheated to 150℃~200℃. The filling time is 10s~25s, the demolding time is 1min~2.5min, and then cool to room temperature to obtain the cast magnesium alloy material.
[0012] II. Heat Treatment: The as-cast magnesium alloy material obtained in step one is subjected to heat treatment, which is carried out in sequence by low-temperature solution treatment, room-temperature water cooling, low-temperature aging and air cooling.
[0013] The low-temperature solution treatment process is as follows: holding at 390℃~420℃ for 2h~8h, with a heating rate of 11℃ / min~13℃ / min;
[0014] The low-temperature aging process is as follows: holding at 150℃~195℃ for 2h~8h, with a heating rate of 8℃ / min~10℃ / min.
[0015] In step one of this invention, a multi-component synergistic alloying strategy of Al-Sn-Zn-Ca is adopted. Through precise design of the magnesium alloy composition, the mechanical properties of the material are improved. Al (8.4%~9.6%) provides sufficient solid solution strengthening effect, Sn (1.2%~2.4%) forms a thermally stable Mg2Sn strengthening phase, and Zn (0.6%~1.2%) not only enhances plasticity but also forms Mg with Al. 17 Al 12 In the composite strengthening network, the trace addition of Ca (0.2%~0.8%) plays a crucial role. It effectively refines the grain structure and combines with Al to form a high-melting-point Al2Ca phase, which helps improve the alloy's creep resistance. The rational proportions and interactions of the components optimize the types and distribution of strengthening phases while controlling costs, laying an ideal compositional foundation for subsequent processing.
[0016] In step one, this invention designs a refined and highly repeatable magnesium alloy melting and casting process system, demonstrating significant advantages in precise control of the melting process, ensuring melt purity, and optimizing the casting process. Starting with raw material pretreatment, surface contaminants are effectively removed through drying. During the melting process, a stepped heating control and sequential feeding strategy are employed to ensure that all constituent elements are fully melted and evenly distributed. Regarding melt quality control, a multi-stage purification system is innovatively introduced, including mechanical stirring and degassing (160 rpm~200 rpm), graphite stirring rod combined with argon refining, and professional slag removal operations. These measures collectively guarantee the high purity of the melt. The casting process parameters have been systematically optimized; the precise coordination of mold preheating temperature (150℃~200℃), casting temperature (685℃~700℃), and filling time (10s~25s) effectively avoids casting defects.
[0017] In step two of this invention, a special heat treatment process was designed to precisely control the microstructure and optimize the performance of magnesium alloys. This heat treatment method employs a low-temperature solution treatment process (390℃~420℃) combined with rapid water quenching (cooling rate of 85℃ / min~95℃ / min), which promotes the full dissolution of strengthening phases and the formation of supersaturated solid solutions, creating favorable conditions for subsequent aging precipitation. During the aging stage, a low-temperature window of 150℃~195℃ was used, and the size, distribution, and volume fraction of precipitated phases were controlled by precisely controlling the holding time (2h~8h). In particular, when aging at 165℃, it was found that holding for 8h achieved the optimal matching of mechanical properties, with a yield strength of 133.8MPa and a room temperature tensile strength of 248.3MPa, while maintaining a good elongation of 5.8%. The entire heat treatment process effectively controlled the microstructure and performance of magnesium alloys through the synergistic effect of controlling the heating rate, holding time, and cooling method. 17 Al 12The dispersed distribution of nanoscale precipitates such as Mg2Sn and Al2Ca allows the precipitates to gradually grow and coarsen, improving the uniformity of distribution, effectively enhancing the tensile strength of the material, and achieving a balance between strength and plasticity. This provides an effective means of microstructure control for the development of high-performance magnesium alloys.
[0018] In summary, this invention provides a method for preparing high-performance Mg-Al-Sn-Zn-Ca magnesium alloys and strengthening them through accurate composition design, highly refined smelting and casting processes, and special heat treatment processes. This method not only significantly improves the mechanical properties of thixotropic injection-cast magnesium alloys but also takes into account environmental friendliness and cost-effectiveness. It provides a new paradigm for expanding the boundaries of semi-solid thixotropic injection casting technology and enriching the magnesium alloy product matrix, and has important guiding significance for promoting the large-scale application of lightweight materials in multiple scenarios. Attached Figure Description
[0019] Figure 1 The mechanical properties of the magnesium alloy prepared in Experiment 1 are shown in the as-cast state (product of Step 1) and after T6 heat treatment (product of Step 2).
[0020] Figure 2 Scanning micrographs of the magnesium alloy prepared for Experiment 1 in the as-cast state and after T6 heat treatment. Detailed Implementation
[0021] Specific Implementation Method 1: This implementation method describes a preparation and heat treatment strengthening method for a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy, which is carried out according to the following steps:
[0022] I. Preparation process of Mg-Al-Sn-Zn-Ca magnesium alloy:
[0023] ① Weigh out pure Mg blocks, pure Al blocks, pure Sn granules, pure Zn blocks and Mg-30wt.%Ca master alloy according to the mass percentage of each element in the magnesium alloy. Remove the dust and oil from the surface of the above raw materials using an angle grinder, and then put them into a forced-air drying oven for drying.
[0024] The magnesium alloy comprises the following elements by mass percentage: Al content is 8.4%~9.6%, Sn content is 1.2%~2.4%, Zn content is 0.6%~1.2%, Ca content is 0.2%~0.8%, impurities Si+Fe+C≤0.015%, and Mg is the balance.
[0025] ② Melting: The dried pure Mg blocks are placed into a crucible and then sent into a melting furnace. The furnace is heated to 520℃~530℃, and a mixture of CO2 and SF6 protective gas is introduced. Then, the temperature is raised to 675℃~685℃ at a heating rate of 7.5℃ / min~10.5℃ / min and held for 80min~100min. After the pure Mg is completely melted into liquid, the pure Al blocks dried in step ①, Mg-30wt.%Ca master alloy, pure Sn blocks and pure Zn blocks are added to the crucible in sequence at intervals of 1min~3min. The holding time after adding the pure Zn blocks is 10min~30min.
[0026] ③ The process of stirring, slag removal, and air refining is carried out in sequence, and then the melt temperature is raised to 685℃~700℃ and held for 3min~5min;
[0027] ④ Pouring: Pour the solution in the crucible into a gravity casting mold preheated to 150℃~200℃. The filling time is 10s~25s, the demolding time is 1min~2.5min, and then cool to room temperature to obtain the cast magnesium alloy material.
[0028] II. Heat Treatment: The as-cast magnesium alloy material obtained in step one is subjected to heat treatment, which is carried out in sequence by low-temperature solution treatment, room-temperature water cooling, low-temperature aging and air cooling.
[0029] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the drying temperature in step one ① is 185℃~205℃, and the drying time is 4h~6h. Everything else is the same as in Specific Implementation Method One.
[0030] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: the crucible mentioned in step one ② is made of 304 stainless steel, with a wall thickness of 6mm~9mm and a depth of 300mm~360mm, and has an inclined pouring nozzle along the upper edge at an angle of 25°~40°. It also has a symmetrical lifting ring hole with a size of Φ14mm~20mm on each side. Everything else is the same as in Specific Implementation Method One or Two.
[0031] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: in step one ②, the volume ratio of CO2 to SF6 in the mixed protective gas of CO2 and SF6 is (20.5~22):1, and the total gas flow rate of the mixed protective gas of CO2 and SF6 is 5.18L / min~5.26L / min. Everything else is the same as in Specific Implementation Methods One to Three.
[0032] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Four in that the stirring process described in step one, ③, is as follows: Open the furnace door, immediately insert a graphite stirring rod preheated to 210℃, and stir at a speed of 160 rpm to 200 rpm for 2 to 4 minutes. Simultaneously, introduce high-purity argon gas at a flow rate of 0.5 L / min to 0.75 L / min, and turn off the heating function during the stirring process. Everything else is the same as in Specific Implementation Method Four.
[0033] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Five in that the slag removal process described in step one, ③, is as follows: After stirring, close the furnace door and allow the smelting furnace to resume heating. Once the temperature reaches 675℃~685℃, immediately use a slag removal spoon preheated to 210℃ to remove the slag. The slag removal time is 0.3min~0.8min. Everything else is the same as in Specific Implementation Method Five.
[0034] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that the gas blowing refining process described in step one ③ is as follows: connect the gas blowing pipeline, open the argon valve and adjust the flow rate to 0.5L / min~0.75L / min, and the refining time is 1min~1.5min. Everything else is the same as in Specific Implementation Method Six.
[0035] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Seven in that the low-temperature solution treatment process described in step two is: maintaining a temperature of 390℃~420℃ for 2h~8h. Everything else is the same as in Specific Implementation Method Seven.
[0036] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Eight in that the heating rate for low-temperature solid solution in step two is 11℃ / min to 13℃ / min. Everything else is the same as in Specific Implementation Method Eight.
[0037] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method Nine in that the low-temperature aging process described in step two is: holding at 150℃~195℃ for 2h~8h, with a heating rate of 8℃ / min~10℃ / min. Everything else is the same as in Specific Implementation Method Nine.
[0038] The invention was verified using the following experiments:
[0039] Experiment 1: This experiment demonstrates a method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy. The specific steps are as follows:
[0040] I. Preparation process of Mg-Al-Sn-Zn-Ca magnesium alloy:
[0041] ① Weigh out pure Mg blocks, pure Al blocks, pure Sn granules, pure Zn blocks and Mg-30wt.%Ca master alloy according to the mass percentage of each element in the magnesium alloy. Remove the dust and oil from the surface of the above raw materials using an angle grinder, and then put them into a forced-air drying oven for drying.
[0042] The magnesium alloy is composed of the following elements by mass percentage: Al content is 8.4%, Sn content is 1.6%, Zn content is 0.8%, Ca content is 0.4%, impurities Si+Fe+C≤0.015%, and Mg is the balance.
[0043] The drying temperature in step 1① is 190℃, and the drying time is 5 hours;
[0044] ② Melting: The dried pure Mg blocks are placed into a crucible and then sent into the melting furnace. The furnace is heated to 525°C, and a mixture of CO2 and SF6 protective gas is introduced. Then, the temperature is raised to 680°C at a rate of 8°C / min and held for 95 minutes. After the pure Mg has completely melted into a liquid, the pure Al blocks dried in step ①, Mg-30wt.%Ca master alloy, pure Sn blocks, and pure Zn blocks are added to the crucible in sequence at 2-minute intervals. The holding time after adding the pure Zn blocks is 20 minutes.
[0045] The crucible mentioned in step 1② is made of 304 stainless steel. The wall thickness and depth of the crucible are 8mm and 320mm respectively. It has an inclined pouring spout on the upper edge with an inclination angle of 35°, and a symmetrical lifting ring hole with a size of Φ16mm on each side.
[0046] In step 1②, the volume ratio of CO2 to SF6 in the mixed protective gas is 21:1, and the total gas flow rate of the mixed protective gas is 5.22 L / min.
[0047] ③ The process of stirring, slag removal, and air refining is carried out in sequence, and then the melt temperature is raised to 695℃ and held for 5 minutes;
[0048] The stirring process described in step 1③ is as follows: Open the furnace door, immediately insert the graphite stirring rod that has been preheated to 210℃ for stirring, the stirring speed is 160rpm, the stirring time is 2.5min, and high-purity argon gas with a flow rate of 0.55L / min is introduced at the same time, and the heating function is turned off during the stirring process.
[0049] The slag removal process described in step 1③ is as follows: After stirring, close the furnace door and allow the smelting furnace to resume heating. Once the temperature reaches 680℃, immediately use a slag removal spoon that has been preheated to 210℃ to remove the slag. The slag removal time is 0.8 minutes.
[0050] The gas blowing refining process described in step 1③ is as follows: connect the gas blowing pipeline, open the argon valve and adjust the flow rate to 0.55L / min, and the refining time is 1.5min;
[0051] ④ Pouring: Pour the solution in the crucible into a gravity casting mold preheated to 180°C. The filling time is 15 seconds, the demolding time is 1.5 minutes, and then cool to room temperature to obtain the cast magnesium alloy material.
[0052] The performance of the as-cast magnesium alloy material obtained above was tested in the following steps: The prepared magnesium alloy ingot was wire-cut along the longitudinal center to take samples, with the sampling position avoiding the top and bottom by a distance of 20 mm. The sample thickness was 2 mm and the width was 4 mm. The obtained samples were polished with 400#~2000# sandpaper in progressively increasing grades until the surface was smooth. Then, a room temperature tensile test was performed on an electronic universal testing machine at a rate of 1 mm / min. The mechanical property data of the alloy in the as-cast state, including yield strength, tensile strength and elongation, were recorded and analyzed.
[0053] Step 2: The as-cast magnesium alloy material obtained in Step 1 is subjected to heat treatment. The heat treatment process is carried out in sequence as low temperature solution treatment, room temperature water cooling, low temperature aging and air cooling, and finally Mg-Al-Sn-Zn-Ca magnesium alloy is obtained.
[0054] The aforementioned low-temperature solution treatment process is as follows: holding at 400℃ for 4 hours, with a heating rate of 12℃ / min;
[0055] The low-temperature aging process is as follows: holding at 165℃ for 8 hours, with a heating rate of 9℃ / min.
[0056] Figure 1 The mechanical properties of the magnesium alloy prepared in Experiment 1 are shown in the as-cast state (product of Step 1) and after T6 heat treatment (product of Step 2). It can be seen that the yield strength in the as-cast state is 106.8 MPa, the tensile strength is 210.4 MPa, and the elongation is 4.2%. After a heat treatment process of low-temperature solution treatment + room-temperature water cooling + low-temperature aging + air cooling, the yield strength of the magnesium alloy reaches 133.8 MPa, the tensile strength reaches 248.3 MPa, and the elongation reaches 5.8%, showing a significant improvement compared to the as-cast properties. This result proves that the low-temperature T6 heat treatment process designed in this invention is beneficial for achieving comprehensive mechanical properties of high strength, toughness, and high elongation under semi-solid thixotropic injection casting conditions, providing a reliable material solution for lightweight components in many high-end manufacturing fields.
[0057] Figure 2 Scanning micrographs of the magnesium alloy prepared in Experiment 1 in the as-cast state and after T6 heat treatment. Figure 2Image a is a scanning micrograph of the as-cast microstructure, which shows that fine, discontinuous precipitates are distributed on the grain boundaries, along with numerous shrinkage pores and voids.
[0058] Figure 2 b is a scanning micrograph of the magnesium alloy after T6 heat treatment. It can be seen that the T6 heat treatment causes the fine, dispersed precipitates (such as Mg) in the as-cast structure to appear. 17 Al 12 The grain structure becomes coarser and rounder, improving the uniformity of the microstructure distribution, making the grain boundary network more obvious, reducing porosity and shrinkage, which is more conducive to improving the overall mechanical properties of the alloy.
Claims
1. A method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy, characterized in that... The method is performed according to the following steps: I. Preparation process of Mg-Al-Sn-Zn-Ca magnesium alloy: ① Weigh out pure Mg blocks, pure Al blocks, pure Sn granules, pure Zn blocks and Mg-30wt.%Ca master alloy according to the mass percentage of each element in the magnesium alloy. Remove the dust and oil from the surface of the above raw materials using an angle grinder, and then put them into a forced-air drying oven for drying. The magnesium alloy comprises the following elements by mass percentage: Al content is 8.4%~9.6%, Sn content is 1.2%~2.4%, Zn content is 0.6%~1.2%, Ca content is 0.2%~0.8%, impurities Si+Fe+C≤0.015%, and Mg is the balance. ② Melting: The dried pure Mg blocks are placed into a crucible and then sent into a melting furnace. The furnace is heated to 520℃~530℃, and a mixture of CO2 and SF6 protective gas is introduced. Then, the temperature is raised to 675℃~685℃ at a heating rate of 7.5℃ / min~10.5℃ / min and held for 80min~100min. After the pure Mg is completely melted into liquid, the pure Al blocks dried in step ①, Mg-30wt.%Ca master alloy, pure Sn blocks and pure Zn blocks are added to the crucible in sequence at intervals of 1min~3min. The holding time after adding the pure Zn blocks is 10min~30min. ③ The process of stirring, slag removal, and air refining is carried out in sequence. Then, the melt temperature is raised to 685℃~700℃ and held for 3min~5min. ④ Pouring: Pour the solution in the crucible into a gravity casting mold preheated to 150℃~200℃. The filling time is 10s~25s, the demolding time is 1min~2.5min, and then cool to room temperature to obtain the cast magnesium alloy material. II. Heat Treatment: The as-cast magnesium alloy material obtained in step one is subjected to heat treatment, which is carried out in sequence by low-temperature solution treatment, room-temperature water cooling, low-temperature aging and air cooling.
2. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 1, characterized in that... The method is carried out according to the following steps: the drying temperature in step one ① is 185℃~205℃, and the drying time is 4h~6h.
3. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 1, characterized in that... The crucible mentioned in step 1② is made of 304 stainless steel. The wall thickness and depth of the crucible are 6mm~9mm and 300mm~360mm, respectively. It has an inclined pouring nozzle on the upper edge with an inclination angle of 25°~40°, and symmetrical lifting ring holes with a size of Φ14mm~20mm on each side.
4. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 1, characterized in that... In step 1②, the volume ratio of CO2 to SF6 in the mixed protective gas is (20.5~22):1, and the total flow rate of the mixed protective gas is 5.18L / min~5.26L / min.
5. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 1, characterized in that... The stirring process described in step 1③ is as follows: Open the furnace door, immediately insert the graphite stirring rod that has been preheated to 210℃ for stirring, the stirring speed is 160rpm~200rpm, the stirring time is 2min~4min, and high-purity argon gas with a flow rate of 0.5L / min~0.75L / min is introduced at the same time. The heating function is turned off during the stirring process.
6. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 1, characterized in that... The slag removal process described in step 1③ is as follows: After stirring, close the furnace door and allow the smelting furnace to resume heating. Once the temperature reaches 675℃~685℃, immediately use a slag removal spoon that has been preheated to 210℃ to remove the slag. The slag removal time is 0.3min~0.8min.
7. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 1, characterized in that... The process of gas blowing refining described in step 1③ is as follows: connect the gas blowing pipeline, open the argon valve and adjust the flow rate to 0.5L / min~0.75L / min, and the refining time is 1min~1.5min.
8. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 1, characterized in that... The low-temperature solution treatment process described in step two involves holding the solution at 390℃~420℃ for 2h~8h.
9. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 8, characterized in that... The heating rate for the low-temperature solid solution in step two is 11℃ / min to 13℃ / min.
10. The method for preparing and heat-treating to strengthen a high-performance Mg-Al-Sn-Zn-Ca magnesium alloy according to claim 9, characterized in that... The low-temperature aging process described in step two is as follows: holding at 150℃~195℃ for 2h~8h, with a heating rate of 8℃ / min~10℃ / min.