CN109136701B - Magnesium alloy material for gravity casting of sand mold and preparation method thereof - Google Patents
Magnesium alloy material for gravity casting of sand mold and preparation method thereof Download PDFInfo
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- C22C23/00—Alloys based on magnesium
- C22C23/02—Alloys based on magnesium with aluminium as the next major constituent
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- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
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- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/06—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of magnesium or alloys based thereon
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Abstract
The invention belongs to the field of metal structure materials, and particularly relates to a magnesium alloy material for sand mold gravity casting and a preparation method thereof. The material consists of the following elements in percentage by mass: al in a%, one or more of La, Ce and Pr in b%, Mn in c%, one or more of RE rare earth elements Gd, Y, Sm, Nd, Er, Eu, Ho, Tm, Lu, Dy and Yb in d%, impurities in a total amount of less than 0.2%, and Mg in the balance, wherein a, b, c and d meet the following condition that a is more than or equal to 3.5 and less than or equal to 4.5; b is more than or equal to 0.5 and less than or equal to 4.5; c is more than or equal to 0.2 and less than or equal to 0.5; d is more than or equal to 0.01 and less than or equal to 2.5. The material has uniform and fine structure, excellent mechanical property and good casting property, and widens the application field of magnesium alloy materials. The invention also provides a preparation method of the sand gravity casting magnesium alloy material with good process stability and high controllability.
Description
Technical Field
The invention belongs to the field of metal structure materials, and particularly relates to a magnesium alloy material for sand mold gravity casting and a preparation method thereof.
Background
Magnesium and its alloy are the lightest metal structure materials that can be used in industry at present, have the advantages of small density (about 2/3 for aluminum and 1/4 for steel), high specific strength and specific stiffness, good damping, machinability and casting performance, and have been widely used in the fields of automobiles, communication electronics, aerospace, and the like. But the absolute strength and plasticity are low, so that the magnesium and the magnesium alloy are mainly used as non-bearing or bearing members, and further popularization and application of the magnesium and the magnesium alloy are restricted.
AE44(Mg-4Al-4RE, wt.%) magnesium alloy is one of commercial magnesium alloys so far, and has excellent room temperature mechanical properties and good high temperature creep resistance. The alloy elements added in the traditional AE44 magnesium alloy are mainly aluminum, manganese and cerium-rich mischmetal, and the structure of the alloy is mainly composed of an alpha-Mg matrix and Al11RE3Needle phase composition. But in service, Al11RE3The needle-shaped phase tip is easy to generate stress concentration and generate cracks, and the mechanical property of the material is deteriorated. In addition, unlike high pressure casting, sand gravity casting has a slow cooling rate, and AE44 sand gravity casting magnesium alloy has a large grain size and a large second phase size, which seriously deteriorates the material performance. Therefore, how to refine the crystal grain size of the matrix and correct Al11RE3The needle-shaped phase and the introduction of the novel strengthening phase are key problems of improving the toughness of the AE44 sand-type gravity casting magnesium alloy and expanding the industrial application range of the magnesium alloy. We have found that: the rare earth elements (1) such as samarium, gadolinium and yttrium and the aluminum element form high-melting-point Al at the early stage of solidification2The RE phase is used as a heterogeneous nucleation core to greatly refine the matrix and introduce a novel fine strengthening phase; (2) solute distribution coefficient k in magnesium<1, enrichment on a solid-liquid interface in the solidification process hinders growth of a matrix and a second phase, so that the matrix can be further refined and the morphology of the second phase can be changed; (3) the magnesium has high solid solubility and solid solution strengthening effect; (4) the solid solubility is reduced along with the temperature change, and the aging strengthening effect is achieved. At present, the research of refining the AE44 magnesium alloy structure by adding the rare earth elements with the characteristics and introducing a novel strengthening phase to improve the obdurability of the alloy is not reported at home and abroad.
Disclosure of Invention
The invention aims to provide a magnesium alloy material for sand gravity casting, which has the advantages of excellent mechanical property, good casting property, small matrix grain size, Al11RE3The phase is granular magnesium alloy material.
The invention also aims to provide a preparation method of the magnesium alloy material for sand gravity casting, which has good process stability.
The purpose of the invention can be realized by the following technical scheme:
a magnesium alloy material for gravity casting of sand molds is characterized in that: the material consists of the following elements in percentage by mass: a percent of Al, b percent of one or a mixture of more of La, Ce and Pr, c percent of Mn, d percent of one or more of RE rare earth elements Gd, Y, Sm, Nd, Er, Eu, Ho, Tm, Lu, Dy and Yb in total, less than 0.2 percent of impurity in total and the balance of Mg, wherein a, b, c and d satisfy the following formulas (1) to (4),
(1)3.5≤a≤4.5；
(2)0.5≤b≤4.5；
(3)0.2≤c≤0.5；
(4)0.01≤d≤2.5。
preferably, the range of d in the formula (4) is: d is more than or equal to 0.1 and less than or equal to 2.5. Gd. Y, Sm, the solid solubility of the rare earth elements in Mg is high, the addition of d in the formula (4) is more than or equal to 0.1, and the aging strengthening effect is more obvious, but the addition of d is more than 2.5, which causes coarsening of the second phase, matrix cutting in the service process and serious deterioration of the mechanical property of the material as a crack initiation point.
Wherein, 1) aluminum is used for balancing the strength and plasticity of the alloy and improving the casting process performance, so that the invention is suitable for industrial batch production. 2) La, Ce and Pr are used for improving the mechanical property of the alloy, and the La, Ce and Pr elements and aluminum preferentially generate Al11RE3Phase, inhibiting the formation of Mg having poor thermal stability17Al12Phase, improving the room temperature and high temperature mechanical properties of the alloy; in addition, the La, Ce and Pr can remove impurities in the magnesium alloy melt during smelting, and the effects of degassing, refining and purifying the melt are achieved. 3) Manganese is used for improving the corrosion resistance of the alloy, and can form a compound with iron or other heavy metal elements in the magnesium alloy, so that most of manganese can be removed as slag; in addition, manganese can promote the aging strengthening effect of the alloy, form Al-Mn nano aging phase and further improve the toughness of the alloy. 4) Rare earth elements such as Gd, Y, Sm and the like have high solid solubility in Mg, and mainly exist in three forms in AE series magnesium alloy: solid solution in the matrix; segregation is in grain boundary, phase boundary and dendrite boundary; solid-soluted in the compound or formed a compound. The addition of the rare earth elements into the alloy can play a role in solid solution strengthening and strength improvement. Solute distribution coefficient k of the above rare earth elements in Mg<1, the rare earth elements have extremely strong chemical activity, can be partially aggregated and adsorbed on a growing grain interface or a dendritic crystal interface to block the growth of grains and dendritic crystals, and can obviously refine the grains and granulate Al11RE3The needle-shaped phase greatly improves the performance, especially the plasticity of the alloy. Further increasing the content of the rare earth can generate fine granular high melting point Al with the Al element preferentially2The RE intermetallic compound can be used as heterogeneous nucleation core refined grains and is dispersed in the matrix, so that the crack initiation position and the expansion path in the alloy fracture process are changed, and the plasticity of the alloy is further improved. In addition, the addition of rare earth elements such as Gd, Y, Sm and the like can promote the aging strengthening effect of the AE series magnesium alloy, and further improve the strength of the alloy.
Preferably, in the magnesium alloy material, the b + d is more than or equal to 3.6 percent and less than or equal to 7.0 percent. More preferably, in the magnesium alloy material, b + d is more than or equal to 4.5% and less than or equal to 6.0%. The addition of b and d determines various properties of the final magnesium alloy material.
Preferably, the combination of La and Ce is selected from the three elements of b%, so that the material structure is more uniform and the mechanical property is better.
Preferably, the types of the d% RE elements are Gd, Y, Sm and Nd elements, the mass ratio of the Gd, the Y, the Sm and the Nd elements is 40-81:31-52:16-30:11-24, and the proper types and the proportion of the rare earth elements are favorable for refining grains and modifying and granulating acicular second phase Al11RE3And the coarsening of the second phase is avoided, and the mechanical property of the alloy can be greatly improved.
A method for preparing a magnesium alloy material by sand gravity casting comprises the following steps,
s1: smelting alloy, namely preheating pure Mg, pure Al, magnesium rare earth intermediate alloy and aluminum manganese or magnesium manganese intermediate alloy respectively;
preferably, in the step S1, the preheating temperature is 200 to 250 ℃, and the preheating time is 2 to 6 hours. The preheating temperature and time can effectively remove the moisture of the raw materials and can avoid the problem of excessive oxidation of the surfaces of the raw materials in the preheating process.
Preferably, in step S1, the magnesium-rare earth intermediate alloy is one or a combination of several intermediate alloys selected from a magnesium-cerium-rich mischmetal intermediate alloy, a magnesium-lanthanum intermediate alloy, a magnesium-cerium intermediate alloy, a magnesium-praseodymium intermediate alloy, a magnesium-samarium intermediate alloy, a magnesium-gadolinium intermediate alloy, a magnesium-yttrium-rich mischmetal intermediate alloy, a magnesium-neodymium intermediate alloy, a magnesium-praseodymium-neodymium mixed rare earth intermediate alloy, a magnesium-erbium intermediate alloy, a magnesium-europium intermediate alloy, a magnesium-holmium intermediate alloy, a magnesium-thulium intermediate alloy, a magnesium-lutetium intermediate alloy, a magnesium-dysprosium intermediate alloy, and a magnesium-ytterbium intermediate alloy.
The cerium-rich mischmetal contains three rare earth elements of Ce, La and Pr.
S2: completely melting the preheated pure Mg in a protective atmosphere; adding preheated pure Al, Al-Mn or Mg-Mn intermediate alloy at 670-690 ℃; when the temperature rises to 720-740 ℃, adding the preheated magnesium rare earth intermediate alloy; heating to 720-740 ℃ after the magnesium rare earth intermediate alloy is completely melted, adding a refining agent for refining, standing at 710-730 ℃ after refining, cooling to 680-700 ℃, skimming scum to obtain a magnesium alloy melt, or pouring to obtain a magnesium alloy ingot;
preferably, in step S2, a refining agent is added to refine the mixture, and the mixture is allowed to stand at 720 ℃ after refining. The refining temperature is 720 ℃, the refining effect is optimal, and the gas and slag can be removed to the greatest extent and the melt can be purified.
S3: and (4) remelting the magnesium alloy melt or the magnesium alloy ingot in the step S2, and then carrying out sand mold gravity casting to obtain a magnesium alloy casting.
Preferably, in the step S3, the magnesium alloy melt or the magnesium alloy ingot is remelted, and then poured into a sand mold preheated to 200 to 300 ℃ at 680 to 700 ℃, and cooled to obtain the magnesium alloy casting. Further preferably, the cooling rate of the sand mold gravity casting is 0.1-20 ℃/s. The pouring temperature can guarantee that the melt has better fluidity in the die, and avoid the burning loss caused by overhigh melt temperature.
The protective atmosphere of the step S2 is SF6And CO2The mixed gas of (1). Preferably, the SF6And CO2Is 1: 99.
the refining agent of the step S2 is a magnesium alloy refining agent containing inorganic salts, preferably, an inorganic salt magnesium alloy refining agent containing sodium salt, potassium salt, fluorine salt or hexachloroethane.
Preferably, the refining agent is added in an amount of 1-5% of the total mass of all raw materials.
The preparation method of the magnesium alloy material for gravity casting of the sand mold, which is related by the invention, also comprises the steps of carrying out solid solution treatment and artificial aging treatment on the magnesium alloy casting prepared in the step S3;
preferably, the temperature of the solution treatment is 400-550 ℃, and the time of the solution treatment is 4-48 hours; the temperature of the artificial aging treatment is 175-225 ℃, and the time of the aging treatment is 1-32 hours. The solution treatment process can dissolve the second phase into the magnesium matrix to the maximum extent; the aging treatment process can enable the casting to obtain obvious aging strengthening effect.
Or directly carrying out artificial aging treatment on the magnesium alloy casting prepared in the step S3, wherein the temperature of the aging treatment is 175-225 ℃, and the time of the aging treatment is 1-32 hours.
Compared with the prior art, the invention has the beneficial effects that:
1. compared with the prior art, the magnesium alloy material prepared by the invention has the advantages that the structure is obviously refined, the second phase is changed into particles from needle-shaped deterioration, and a new phase Al is introduced2RE, the toughness of the alloy is obviously improved.
2. After the alloy is subjected to direct aging (T5) or solid solution and artificial aging (T6), the mechanical property of the magnesium alloy material is effectively improved.
3. The preparation method is simple, the process stability is good, and the process controllability is high.
Drawings
FIG. 1 is a metallographic structure of an alloy of comparative example 1, in which the morphology of the second phase is a typical needle-like phase.
FIG. 2 is a metallographic structure of the alloy of comparative example 1, showing an average size of the magnesium matrix of about 1021. mu.m.
FIG. 3 is a metallographic structure of an alloy of example 6 of the present invention, in which the second phase is refined and is in the form of fine particles.
FIG. 4 is a metallographic representation of the alloy of example 6 according to the invention, showing a substantially refined magnesium matrix with an average size of about 261 μm.
FIG. 5 is a tensile stress strain curve for the alloy of comparative example 1.
FIG. 6 is a tensile stress-strain curve of the alloy of example 6 of the present invention, wherein the tensile strength and plasticity of the alloy are simultaneously improved.
Detailed Description
The invention will now be further illustrated by reference to the following examples:
the various master alloys used in the following examples are commercially available and are commercially available from Ganzhou Feiteng light alloys, Inc.
Example 1:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 3.82% of Al, 2.20% of Ce, 1.14% of La, 1.17% of Pr, 0.01% of Sm, 0.32% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 670 ℃, adding preheated pure aluminum, magnesium and manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 720 ℃, adding the preheated magnesium-cerium-rich mischmetal intermediate alloy and magnesium-samarium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised back to 720 ℃, standing at 720 ℃ after refining, cooling to 680 ℃, and skimming scum to obtain a magnesium alloy melt; and pouring to obtain the magnesium alloy ingot.
The gravity casting process of the sand mold comprises the following steps:
and remelting the magnesium alloy ingot, pouring the magnesium alloy ingot into a sand mold preheated to 300 ℃ at 680 ℃ to obtain a magnesium alloy casting, and testing the cooling rate to be 20 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 1 of the present invention were tested using a universal tensile testing machine, and the test results are shown in table 1.
Example 2:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 3.74% of Al, 1.98% of Ce, 1.04% of La, 1.09% of Pr, 0.44% of Sm, 0.12% of Nd, 0.03% of Er, 0.30% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 250 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 680 ℃, adding preheated pure aluminum, magnesium and manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 730 ℃, adding the preheated magnesium-cerium-rich mischmetal intermediate alloy, the magnesium samarium intermediate alloy, the magnesium praseodymium neodymium intermediate alloy and the magnesium erbium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 730 ℃, standing at 720 ℃ after refining, cooling to 690 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and remelting the magnesium alloy ingot, pouring the magnesium alloy ingot into a sand mold preheated to 250 ℃ at 690 ℃ to obtain a magnesium alloy casting, and testing the cooling rate to be 9.4 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 2 of the present invention were tested by using a universal tensile testing machine, and the test results are shown in table 1.
Example 3:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 3.94% of Al, 4.09% of La, 1.12% of Sm, 0.21% of Nd, 0.03% of Er, 0.30% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 6 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 690 ℃, adding the preheated pure aluminum, magnesium and manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 740 ℃, adding the preheated magnesium-lanthanum intermediate alloy, magnesium-samarium intermediate alloy, magnesium-neodymium intermediate alloy and magnesium-erbium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 740 ℃, standing at 720 ℃ after refining, cooling to 700 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and remelting the magnesium alloy ingot, and pouring the magnesium alloy ingot into a sand mold preheated to 200 ℃ at 700 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 10.4 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 3 of the present invention were tested by using a universal tensile testing machine, and the test results are shown in table 1.
Example 4:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 4.11% of Al, 2.11% of Ce, 2.14% of La, 0.43% of Gd, 0.01% of Dy, 0.02% of Yb, 0.50% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and aluminum-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 670 ℃, adding preheated pure aluminum and aluminum-manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 720 ℃, adding the preheated magnesium lanthanum intermediate alloy, the preheated magnesium cerium intermediate alloy, the preheated magnesium gadolinium intermediate alloy, the preheated magnesium dysprosium intermediate alloy and the preheated magnesium ytterbium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised back to 720 ℃, standing at 720 ℃ after refining, cooling to 680 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 300 ℃ at 680 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is tested to be 16.7 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 4 of the present invention were tested by using a universal tensile testing machine, and the test results are shown in table 1.
Example 5:
the magnesium alloy for gravity casting by sand mold comprises (by mass percent) 3.94% of Al, 2.01% of Ce, 1.02% of La, 1.06% of Pr, 0.86% of Gd, 0.02% of Dy, 0.03% of Yb, 0.34% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 690 ℃, adding the preheated pure aluminum, magnesium and manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 740 ℃, adding the preheated magnesium cerium-rich mischmetal intermediate alloy, the magnesium gadolinium intermediate alloy, the magnesium dysprosium intermediate alloy and the magnesium ytterbium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 740 ℃, standing at 720 ℃ after refining, cooling to 700 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 200 ℃ at 700 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 11.7 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 5 of the present invention were tested using a universal tensile testing machine, and the test results are shown in table 1.
Example 6:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 3.88 percent of Al, 1.81 percent of Ce, 0.93 percent of La, 0.92 percent of Pr, 1.29 percent of Gd, 0.03 percent of Dy, 0.05 percent of Yb, 0.29 percent of Mn, less than 0.2 percent of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and aluminum-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 680 ℃, adding preheated pure aluminum and aluminum-manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 730 ℃, adding the preheated magnesium cerium-rich mischmetal intermediate alloy, the magnesium gadolinium intermediate alloy, the magnesium dysprosium intermediate alloy and the magnesium ytterbium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 730 ℃, standing at 720 ℃ after refining, cooling to 690 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 250 ℃ at 690 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 5.4 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 6 of the present invention were tested using a universal tensile testing machine, and the test results are shown in table 1.
Example 7:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 3.94% of Al, 0.25% of Ce, 0.12% of La, 0.13% of Pr, 2.35% of Gd, 0.08% of Dy, 0.07% of Yb, 0.29% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and aluminum-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 670 ℃, adding preheated pure aluminum and aluminum-manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 720 ℃, adding the preheated magnesium cerium-rich mischmetal intermediate alloy, the magnesium gadolinium intermediate alloy, the magnesium dysprosium intermediate alloy and the magnesium ytterbium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised back to 720 ℃, standing at 720 ℃ after refining, cooling to 680 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 300 ℃ at 680 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 0.1 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 7 of the present invention were measured using a universal tensile tester, and the test results are shown in table 1.
Example 8:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 4.50% of Al, 2.21% of Ce, 1.13% of La, 1.17% of Pr, 0.40% of Y, 0.06% of Er, 0.03% of Ho, 0.01% of Tm, 0.41% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and aluminum-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 680 ℃, adding preheated pure aluminum and aluminum-manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 730 ℃, adding the preheated magnesium-cerium-rich mischmetal intermediate alloy and the preheated magnesium-yttrium-rich mischmetal intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 730 ℃, standing at 720 ℃ after refining, cooling to 690 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 250 ℃ at 690 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is tested to be 18.4 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 8 of the present invention were tested using a universal tensile testing machine, and the test results are shown in table 1.
Example 9:
the novel high-strength and high-toughness sand mold gravity casting magnesium alloy comprises the following alloy components in percentage by mass: 3.94% of Al, 1.92% of Ce, 2.07% of La, 0.40% of Gd, 0.31% of Y, 0.16% of Sm, 0.11% of Nd and 0.34% of Mn, and the balance of Mg, wherein the content of other inevitable impurities is less than 0.2%.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and aluminum-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 670 ℃, adding preheated pure aluminum and aluminum-manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 720 ℃, adding the preheated magnesium lanthanum intermediate alloy, magnesium cerium intermediate alloy, magnesium gadolinium intermediate alloy, magnesium yttrium intermediate alloy, magnesium samarium intermediate alloy and magnesium neodymium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised back to 720 ℃, standing at 720 ℃ after refining, cooling to 680 ℃, skimming scum to obtain a magnesium alloy melt, and pouring to obtain a magnesium alloy ingot;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 300 ℃ at 680 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 9.4 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 9 of the present invention were measured using a universal tensile tester, and the test results are shown in table 1.
Example 10:
the alloy components (mass percent) of the sand gravity casting magnesium alloy are as follows: 4.02% of Al, 1.86% of Ce, 1.94% of La, 0.81% of Gd, 0.52% of Y, 0.30% of Sm, 0.24% of Nd, 0.37% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy sand mold gravity casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 690 ℃, adding the preheated pure aluminum, magnesium and manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 740 ℃, adding the preheated magnesium-lanthanum intermediate alloy, magnesium-cerium intermediate alloy, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-samarium intermediate alloy and magnesium-neodymium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 740 ℃, standing at 720 ℃ after refining, cooling to 700 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 200 ℃ at 700 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is tested to be 11.6 ℃/s.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 10 of the present invention were measured using a universal tensile tester, and the test results are shown in table 1.
Comparative example 1
The alloy of comparative example 1 had the following composition (mass percent): 3.94% of Al, 2.01% of Ce, 1.02% of La, 1.06% of Pr, 0.34% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 690 ℃, adding the preheated pure aluminum, magnesium and manganese intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature is increased to 740 ℃, adding the preheated magnesium-cerium mixed rare earth intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 740 ℃, standing at 720 ℃ after refining, cooling to 700 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 200 ℃ at 700 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 11.4 ℃/s.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 1 were measured using a universal tensile tester, and the test results are shown in table 1.
Comparative example 2
The alloy of comparative example 2 comprises the following components (in percentage by mass): 4.02% of Al, 1.86% of Ce, 1.94% of La, 0.81% of Gd, 0.52% of Y, 0.30% of Sm, 0.24% of Nd, 0.34% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 690 ℃, adding preheated pure aluminum, magnesium manganese and aluminum titanium intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 740 ℃, adding the preheated magnesium-lanthanum intermediate alloy, magnesium-cerium intermediate alloy, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-samarium intermediate alloy and magnesium-neodymium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 740 ℃, standing at 720 ℃ after refining, cooling to 700 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 200 ℃ at 700 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 12.6 ℃/s.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 2 were tested using a universal tensile tester, and the test results are shown in table 1. The result shows that the mechanical property of the alloy is not beneficial to the addition of Ti, and no Ti element is found by detecting the alloy elements by using an inductively coupled plasma spectrometer, because the solid solubility of Ti in Mg is almost zero, the Ti is difficult to be added into the alloy. In addition, the addition of Ti to the alloy further increases the use cost of the alloy.
Comparative example 3
The alloy of comparative example 3 comprises the following components (in percentage by mass): : 4.02% of Al, 1.86% of Ce, 1.94% of La, 0.81% of Gd, 0.52% of Y, 0.30% of Sm, 0.24% of Nd, 0.34% of Mn, less than 0.2% of other inevitable impurities and the balance of Mg.
The embodiment relates to a smelting method of a conventional rare earth magnesium alloy and an alloy casting method in the invention:
wherein the smelting process is carried out in SF6And CO2The method is carried out under the protection of mixed gas and comprises the following steps:
(1) drying materials: preheating smelting raw materials for 3 hours at 200 ℃;
(2) melting magnesium: putting the dried pure magnesium into SF6/CO2Melting in a crucible resistance furnace under the protection of gas;
(3) adding pure aluminum and magnesium-manganese intermediate alloy: when the pure magnesium is completely melted and the temperature reaches 690 ℃, adding preheated pure aluminum, magnesium manganese and aluminum niobium intermediate alloy;
(4) adding magnesium rare earth intermediate alloy: when the temperature rises to 740 ℃, adding the preheated magnesium-lanthanum intermediate alloy, magnesium-cerium intermediate alloy, magnesium-gadolinium intermediate alloy, magnesium-yttrium intermediate alloy, magnesium-samarium intermediate alloy and magnesium-neodymium intermediate alloy;
(5) after the magnesium rare earth intermediate alloy is melted, adding a refining agent for refining when the temperature of the melt is raised to 740 ℃, standing at 720 ℃ after refining, cooling to 700 ℃, and skimming scum to obtain a magnesium alloy melt;
the gravity casting process of the sand mold comprises the following steps:
and pouring the magnesium alloy melt into a sand mold preheated to 200 ℃ at 700 ℃ to obtain a magnesium alloy casting, wherein the cooling rate is 10.5 ℃/s.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 3 were measured using a universal tensile tester, and the test results are shown in table 1. The result shows that the addition of Nb is not beneficial to the mechanical property of the alloy, and no Nb element is found by detecting the alloy elements by using an inductively coupled plasma spectrometer, because the solid solubility of Nb in Mg is almost zero, Nb is difficult to be added into the alloy. In addition, the addition of Nb to the alloy further increases the use cost of the alloy.
TABLE 1 test results of mechanical properties at room temperature of sand mold gravity cast magnesium alloys obtained in examples 1 to 10 of the present invention and comparative examples 1 to 3
As can be seen from Table 1, the sand mold gravity casting magnesium alloy obtained in the examples of the present invention has greatly improved mechanical properties as compared with comparative example 1. In particular, the mechanical properties of example 10 were more remarkable.
Example 11
The sand mold gravity casting magnesium alloy obtained in the embodiment 10 of the invention is subjected to aging treatment at 175 ℃ for 32 hours, and the cooling mode of the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 11 of the present invention were measured using a universal tensile testing machine, and the test results are shown in table 2.
Example 12
The sand mold gravity casting magnesium alloy obtained in the embodiment 10 of the invention is subjected to aging treatment for 16 hours at 200 ℃, and the cooling mode of the solution treatment and the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 12 of the present invention were measured using a universal tensile tester, and the test results are shown in table 2.
Example 13
The sand mold gravity casting magnesium alloy obtained in the embodiment 10 of the invention is subjected to aging treatment at 225 ℃ for 1 hour, and the cooling mode of the aging treatment is water cooling.
The room temperature mechanical properties of the sand gravity cast magnesium alloy obtained in example 13 of the present invention were measured using a universal tensile tester, and the test results are shown in table 2.
Example 14
The sand mold gravity casting magnesium alloy obtained in the embodiment 10 of the invention is subjected to solid solution treatment for 48 hours at 400 ℃ and aging treatment for 32 hours at 175 ℃, and the cooling mode of the solid solution treatment and the aging treatment is water cooling.
The room temperature mechanical properties of the sand gravity cast magnesium alloy obtained in example 14 of the present invention were measured using a universal tensile tester, and the test results are shown in table 2.
Example 15
The sand mold gravity casting magnesium alloy obtained in the embodiment 10 of the invention is subjected to solution treatment for 24 hours at 500 ℃ and aging treatment for 16 hours at 200 ℃, and the cooling mode of the solution treatment and the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity casting magnesium alloy obtained in example 15 of the present invention were measured using a universal tensile testing machine, and the test results are shown in table 2.
Example 16
The sand mold gravity casting magnesium alloy obtained in the embodiment 10 of the invention is subjected to solid solution treatment for 4 hours at 550 ℃ and aging treatment for 1 hour at 225 ℃, and the cooling mode of the aging treatment is water cooling.
The room temperature mechanical properties of the sand gravity cast magnesium alloy obtained in example 16 of the present invention were measured using a universal tensile tester, and the test results are shown in table 2.
Comparative example 4
The sand mold gravity casting magnesium alloy obtained in the comparative example 1 is subjected to an aging treatment at 175 ℃ for 32 hours, and the cooling mode of the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 4 were measured using a universal tensile tester, and the test results are shown in table 2.
Comparative example 5
The sand mold gravity casting magnesium alloy obtained in the comparative example 1 is subjected to an aging treatment at 200 ℃ for 16 hours, and the cooling mode of the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 5 were tested using a universal tensile tester, and the test results are shown in table 2.
Comparative example 6
The sand mold gravity casting magnesium alloy obtained in the comparative example 1 is subjected to an aging treatment at 225 ℃ for 1 hour, and the cooling mode of the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 6 were measured using a universal tensile tester, and the test results are shown in table 2.
Comparative example 7
The sand mold gravity casting magnesium alloy obtained in comparative example 1 was subjected to a solution treatment at 400 ℃ for 48 hours and an aging treatment at 175 ℃ for 32 hours, wherein the cooling method of the solution and aging treatment was water cooling.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 7 were measured using a universal tensile tester, and the test results are shown in table 2.
Comparative example 8
The sand mold gravity casting magnesium alloy obtained in the comparative example 1 is subjected to a solution treatment at 500 ℃ for 24 hours and an aging treatment at 200 ℃ for 16 hours, and the cooling method of the solution treatment and the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 8 were tested using a universal tensile tester, and the test results are shown in table 2.
Comparative example 9
The sand mold gravity casting magnesium alloy obtained in the comparative example 1 is subjected to a solution treatment at 550 ℃ for 4 hours and an aging treatment at 225 ℃ for 1 hour, and the cooling method of the solution treatment and the aging treatment is water cooling.
The room temperature mechanical properties of the sand mold gravity cast magnesium alloy obtained in comparative example 9 were measured using a universal tensile tester, and the test results are shown in table 2.
Table 2 mechanical properties at room temperature of sand mold gravity cast magnesium alloys after solid solution + artificial aging treatment (T6) or direct aging treatment (T5) obtained in inventive examples 11 to 19 and comparative examples 4 to 9.
As shown in Table 2, after the sand mold gravity casting magnesium alloy obtained by the invention is subjected to solid solution and artificial aging treatment (T6) or direct aging treatment (T5), the magnesium alloy has a remarkable solid solution aging strengthening effect, and the mechanical properties of the alloy at room temperature can be effectively improved.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention, and the present invention should not be limited by the disclosure of the preferred embodiments. Therefore, it is intended that all equivalents and modifications which do not depart from the spirit of the invention disclosed herein are deemed to be within the scope of the invention.
Claims (10)
1. A magnesium alloy material for gravity casting of sand molds is characterized in that: the material consists of the following elements in percentage by mass: a% of Al, b% of one or a mixture of more of La, Ce and Pr, c% of Mn, d% of RE rare earth elements in total, less than 0.2% of impurities in total, and the balance of Mg, wherein a, b, c and d satisfy the following formulas (1) to (4),
(1)3.5≤a≤4.5；
(2)0.5≤b≤4.5；
(3)0.2≤c≤0.5；
(4)0.01≤d≤2.5；
the types of the d% RE elements are Gd, Y, Sm and Nd elements, and the mass ratio of the Gd, the Y, the Sm and the Nd elements is 40-81:31-52:16-30: 11-24.
2. A method for preparing a magnesium alloy material for sand gravity casting according to claim 1, comprising the following steps,
s1: smelting alloy, namely preheating pure Mg, pure Al, magnesium rare earth intermediate alloy and aluminum manganese or magnesium manganese intermediate alloy respectively;
s2: completely melting the preheated pure Mg in a protective atmosphere; adding preheated pure Al, Al-Mn or Mg-Mn intermediate alloy at 670-690 ℃; when the temperature rises to 720-740 ℃, adding the preheated magnesium rare earth intermediate alloy; heating to 720-740 ℃ after the magnesium rare earth intermediate alloy is completely melted, adding a refining agent for refining, standing at 710-730 ℃ after refining, cooling to 680-700 ℃, skimming scum to obtain a magnesium alloy melt, or pouring to obtain a magnesium alloy ingot;
s3: and (4) remelting the magnesium alloy melt or the magnesium alloy ingot in the step S2, and then carrying out sand mold gravity casting to obtain a magnesium alloy casting.
3. The preparation method of the magnesium alloy material for sand gravity casting according to claim 2, which is characterized by comprising the following steps: in the step S1, the preheating temperature is 200-250 ℃ and the preheating time is 2-6 hours.
4. The preparation method of the magnesium alloy material for sand gravity casting according to claim 2, which is characterized by comprising the following steps: in the step S1, the magnesium-rare earth intermediate alloy is one or a combination of several intermediate alloys of magnesium-cerium-rich mixed rare earth intermediate alloy, magnesium-lanthanum intermediate alloy, magnesium-cerium intermediate alloy, magnesium-praseodymium intermediate alloy, magnesium-samarium intermediate alloy, magnesium-gadolinium intermediate alloy, magnesium-yttrium-rich mixed rare earth intermediate alloy, magnesium-neodymium intermediate alloy, magnesium-praseodymium-neodymium mixed rare earth intermediate alloy, magnesium-erbium intermediate alloy, magnesium-europium intermediate alloy, magnesium-holmium intermediate alloy, magnesium-thulium intermediate alloy, magnesium-lutetium intermediate alloy, magnesium-dysprosium intermediate alloy, and magnesium-ytterbium intermediate alloy.
5. The preparation method of the magnesium alloy material for sand gravity casting according to claim 2, which is characterized by comprising the following steps: the protective atmosphere of the step S2 is SF6And CO2The mixed gas of (1).
6. The preparation method of the magnesium alloy material for sand gravity casting according to claim 2, which is characterized by comprising the following steps: the adding amount of the refining agent in the step S2 is 1-5% of the total mass of all raw materials.
7. The preparation method of the magnesium alloy material for sand gravity casting according to claim 2, which is characterized by comprising the following steps: in the step S3, the magnesium alloy melt or the magnesium alloy ingot is remelted, poured into a sand mold preheated to 200-300 ℃ at 680-700 ℃, and cooled to obtain a magnesium alloy casting.
8. The preparation method of the magnesium alloy material for sand gravity casting according to claim 7, which is characterized by comprising the following steps: the cooling rate of the sand mold gravity casting is 0.1-20 ℃/s.
9. The preparation method of the magnesium alloy material for sand gravity casting according to claim 2, which is characterized by comprising the following steps: the preparation method also comprises the step of carrying out solid solution treatment and artificial aging treatment on the magnesium alloy casting prepared in the step S3;
the temperature of the solution treatment is 400-550 ℃, and the time of the solution treatment is 4-48 hours;
the temperature of the artificial aging treatment is 175-225 ℃, and the time of the aging treatment is 1-32 hours.
10. The casting method according to claim 2, wherein the production method further comprises subjecting the magnesium alloy casting produced in step S3 to direct aging treatment at 175 to 225 ℃ for 1 to 32 hours.
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| CN105463280A (en) * | 2015-12-14 | 2016-04-06 | 山东华盛荣镁业科技有限公司 | Magnesium alloy with high thermal conductivity and preparation method of magnesium alloy |
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| CN105463280A (en) * | 2015-12-14 | 2016-04-06 | 山东华盛荣镁业科技有限公司 | Magnesium alloy with high thermal conductivity and preparation method of magnesium alloy |
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