CN113699422A - High-performance magnesium alloy with tension-compression symmetry and preparation method thereof - Google Patents
High-performance magnesium alloy with tension-compression symmetry and preparation method thereof Download PDFInfo
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- C22C23/00—Alloys based on magnesium
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- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/002—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working by rapid cooling or quenching; cooling agents used therefor
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- 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
Abstract
The invention discloses a high-performance magnesium alloy with tension-compression symmetry and a preparation method thereof, and the method comprises the following steps: 1, preheating a pure magnesium ingot, then heating to 280 ℃, and putting the pure magnesium ingot in a protective atmosphere; 2, heating to 750 ℃ to melt the pure magnesium ingot, and sequentially adding the intermediate alloy, wherein the element proportion is as follows: 14.0-15.5% of Gd, 2.8-3.6% of Zn, 0.5-0.8% of Zr, 0.5-1.5% of Nd, 0.3-0.6% of Ti, 0.1-0.5% of Mn and the balance of Mg; 3 stirring, deslagging, standing and pouring into a mold; 4, demoulding after air cooling, and then oil cooling; 5, solution treatment; 6, heating to 100-120 ℃, preserving the heat for 14-16h, and then cooling to room temperature in air to realize primary aging; then heating to 180-200 ℃, preserving the heat for 12-14h, and then cooling to room temperature in air to obtain a secondary aging casting. The magnesium alloy has outstanding tension-compression symmetry and high strength.
Description
Technical Field
The invention relates to a magnesium alloy, in particular to a high-performance magnesium alloy with tension-compression symmetry. The invention also relates to a preparation method of the high-performance magnesium alloy with tension-compression symmetry, and belongs to the technical field of lightweight metal structural materials.
Background
At present, the energy consumption and the environmental pollution are becoming serious due to the vigorous development of the industries such as automobiles, rail transit, aerospace and the like. Magnesium is one of the most important light metal elements and is a novel green environment-friendly material, and the density of the magnesium is only 1.74g/cm3The composite material is the lightest among all metal structural materials, and can effectively reduce energy consumption and environmental pollution. Compared with the traditional steel material, the magnesium alloy has low density, good formability and shock absorption, excellent electric and heat conducting performance and good dimensional stability, and has wide application prospect in the fields of automobiles, rail transit, aerospace and the like.
With the rapid development of aerospace technology in China, the magnesium alloy is gradually popularized and applied to products such as stroker, helicopter, missile, satellite and the like. At present, the cast magnesium alloy is already used for manufacturing important parts such as skins and frames of airplanes and missiles, tail speed reduction casings of helicopters, fighter wing ribs and the like. When the magnesium alloy is applied to frames and ribs on airplane wings, the stress condition of the wings is extremely complex in the flying process, so that the parts are required to have isotropy in mechanical properties. It is necessary that the magnesium alloy used herein has tensile and compression symmetry to ensure that the part still maintains good mechanical stability when being subjected to loads in various directions. These parts have complicated shapes, cannot be deformed and formed, and need to be directly formed by casting. However, the performance of the common cast magnesium alloy is poorer than that of the extruded magnesium alloy, and the yield strength of the common cast magnesium alloy is lower. Common magnesium alloy casting strengthening methods include alloying and heat treatment.
It has been found that the addition of a proper amount of Gd and Zn elements to the alloy can form a lamellar structure, thereby improving the mechanical properties of the alloy (reference: S.Q.Yin, Z.Q.Zhang, X.Liu, Q.C.Le, Q.Lan, L.Bao, J.Z.Cui.Effect of Zn/Gd ratio on the microstructure and mechanical properties of Mg-Zn-Gd-Zr alloy [ J ]. Materials Science and Engineering: A,2017,695: 135-. In the as-cast Mg-12Gd-2Zn-xNd-0.4Zr (x ═ 0,0.5, and 1 wt.%) alloy (ref: L.X.hong, R.X.Wang, X.B.Zhang.Effects on semiconductor and mechanical properties of as-cast Mg-12Gd-2Zn-xNd-0.4Zr alloys with stabilizing faults [ J ]. International Journal of mineral, metallic and Materials, https:// doi.org/10.1007/s 12613-021-. And the mechanical property of the alloy is slightly improved after the Nd is added.
The mechanical properties of the magnesium alloy can be obviously improved by carrying out heat treatment on the magnesium alloy, the T6 heat treatment (ZM 6 magnesium alloy structure and performance influence of double-stage aging on ZM6 magnesium alloy [ D ]. Harbin university of Physician 2015) is studied on the as-cast ZM6 magnesium alloy, the aging treatment is double-stage aging, a precipitation strengthening phase which is finely dispersed and distributed can be formed in the structure, and the tensile strength and the elongation of the alloy are improved. During solution treatment, the alloy can reach the solution temperature at a higher heating rate, the size of crystal grains in an alloy structure can be regulated, the Gd and Zn content around the crystal grains is increased, an LPSO structure is easily formed, the volume fraction of the LPSO structure is increased, dislocation movement is hindered when the alloy deforms, and therefore the mechanical property of the alloy is improved.
When the magnesium alloy is applied to a wing rib of an airplane, the magnesium alloy mainly bears a transverse stressed framework during normal flight, and plays a role in supporting the skin of the airplane wing. However, under the influence of the air flow, the stress is complicated, and the wing ribs are subjected to longitudinal load due to slight shaking of the wing spars. If the rib does not have tension-compression symmetry, the rib is easy to crack when subjected to longitudinal load, and the rib can even break seriously. There is therefore a need for magnesium alloys for wing ribs having good tension and compression symmetry. Basal plane slippage often occurs in the stretching process of the as-cast magnesium alloy, non-basal plane slippage often occurs in the compression process, and the slippage mechanisms of the two stress modes are different, so that the tensile yield strength and the compressive yield strength of the alloy are different.
In addition, the drawing-pressing asymmetry of the as-cast magnesium alloy is often caused by that twin crystals are formed in the alloy during drawing to block the slip of dislocation, so that the tensile yield strength is high. A study reported that the as-cast Mg-Zn-Y-Mn alloy has a draw-press asymmetry and that the draw-press asymmetry of the alloy can be improved by adding Ti thereto (references: J.Q.Hao, J.S.Zhang, C.X.Xu, Y.T.Zhang. effects of Ti addition on the formation of LPSO phase and yield of Mg-Zn-Y-Mn alloy [ J ]. Materials Science and Engineering: A,2018,735:99-103), and the as-cast alloy itself has a ratio of compressive yield strength to tensile yield strength of 0.91 and a ratio of 1.01 after adding 0.5 wt% of Ti. However, the mechanical property of the alloy is poor, and the yield strength is about 130 MPa. As-cast Mg-12Gd-2Zn-xNd-0.4Zr (x 0,0.5, and 1 wt.%) alloy (ref: L.X.hong, R.X.Wang, X.B.Zhang.Effect of Nd on micro structure and mechanical properties of as-cast Mg-12Gd-2Zn-xNd-0.4Zr alloys with stabilizing faults [ J ]. International Journal of mineral, metallic and Materials, https:// doi.org/10.1007/s12613-021-2264-8) also has a tensile asymmetry, with a ratio of 1.30 at a Nd content of 0 wt.%, and a reduction to 1.05 after addition of 1 wt.% Nd. But the mechanical property of the alloy is poor, and the yield strength is about 150 MPa.
In 2014, 29.1, and published as CN 103540881a, a processing method for improving the tension-compression asymmetry of magnesium alloy is disclosed. The patent application of Chinese invention with publication number CN 103194702A in 7/10/2013 discloses an induction heat treatment process for reducing tension-compression asymmetry of a magnesium alloy material. In both of the above two patent applications, the alloy is subjected to uniform heat treatment or induction heat treatment to reduce the tension-compression asymmetry on the premise that the alloy already has the tension-compression asymmetry. The defect is that the problem of tension-compression asymmetry is not solved in the aspects of alloy component design and alloy preparation process. In addition, the magnesium alloy plate or bar is subjected to extrusion, and if the magnesium alloy in a complex shape is cast, the drawing and pressing asymmetry exists, the effect of the process cannot be predicted. Therefore, it is very important to design a high-performance magnesium alloy material with tension-compression symmetry and a preparation method thereof.
Disclosure of Invention
The invention aims to solve the problems that magnesium alloy castings applied to wing ribs of airplane wings in the prior art are insufficient in strength, have tension-compression asymmetry, cannot be strengthened by deformation processing means and the like, and provides a high-performance magnesium alloy with tension-compression symmetry, which has outstanding tension-compression symmetry, stable performance and batch production.
In order to solve the technical problems, the high-performance magnesium alloy with tension-compression symmetry comprises Mg, Gd, Zn, Zr, Nd, Ti and Mn, and the mass percentages of the elements are as follows: 14.0-15.5% of Gd, 2.8-3.6% of Zn, 0.5-0.8% of Zr, 0.5-1.5% of Nd, 0.3-0.6% of Ti, 0.1-0.5% of Mn and the balance of Mg.
As a preferable scheme of the invention, the magnesium alloy casting obtained by the magnesium alloy after pouring, solid solution and two-stage aging treatment has the structure consisting of an alpha-Mg matrix phase, an X phase containing an LPSO structure and Mn in dispersed distribution2(Nd, Ti), Mg (Zn, Zr) and Zn2Zr precipitates the phase composition, and the crystal grain edge of the matrix also forms an LPSO structure.
In a preferable embodiment of the present invention, the magnesium alloy casting has a ratio of compressive yield strength to tensile yield strength of 1 ± 0.05.
As a preferred scheme of the invention, the mass percentages of the elements are as follows: 15.0% Gd, 2.8% Zn, 0.5% Zr, 0.5% Nd, 0.5% Ti, 0.3% Mn, the balance Mg.
As a preferred scheme of the invention, the mass percentages of the elements are as follows: 14.0% Gd, 3.6% Zn, 0.6% Zr, 1.0% Nd, 0.6% Ti, 0.5% Mn, the balance Mg.
As a preferred scheme of the invention, the mass percentages of the elements are as follows: 15.5% Gd, 2.8% Zn, 0.8% Zr, 1.5% Nd, 0.3% Ti, 0.1% Mn, and the balance Mg.
Compared with the prior art, the invention has the following beneficial effects: the high-performance magnesium alloy prepared by the method has high strength and excellent mechanical property, the tensile yield strength can reach more than 365MPa, the alloy has excellent tension and compression symmetry, and the ratio of the compressive yield strength to the tensile yield strength can be accurately controlled within 1 +/-0.05. Secondly, in the aspect of alloy component design, Nd, Mn and Ti elements are added into the alloy in the current common Mg-Gd-Zn-Zr system, the alloy has uniform structure, and the alloy structure consists of an alpha-Mg matrix phase, an X phase with a long-period stacking ordered (namely LPSO) structure and Mn dispersed and distributed in the X phase2(Nd, Ti) and Mg (Zn, Zr) and Zn dispersed in the matrix2Zr precipitates the phase composition, and the crystal grain edge of the matrix also forms an LPSO structure. ③ fine and dispersedly distributed Mg (Zn, Zr) and Zn2Zr is precipitated in the heat treatment process and distributed in the matrix grains, so that dislocation movement can be hindered, and the strength of the alloy is improved. Mn2(Nd, Ti) is distributed in an X phase at the edge of a grain boundary and is used as a heterogeneous nucleation core to play a role in obviously refining grains; and Mn2(Nd, Ti) is also a strengthening phase, and can play a role of pinning dislocation when the material is deformed, so that the mechanical property of the material is obviously improved. The magnesium alloy can be applied to manufacturing magnesium alloy products such as wing ribs of airplane wings and the like which cannot be strengthened by deformation processing means, and other important parts.
The invention also aims to provide a preparation method of the high-performance magnesium alloy with the tension-compression symmetry, and the magnesium alloy casting manufactured by the method has the advantages of outstanding tension-compression symmetry, stable performance and contribution to mass production.
In order to solve the technical problems, the preparation method of the high-performance magnesium alloy with tension-compression symmetry comprises the following steps in sequence,
the first step is as follows: firstly, putting a pure magnesium ingot into a heat treatment furnace to be preheated to be dry, then heating a smelting furnace to 280 ℃, and introducing CO2+SF6Mixing protective gas, and putting the preheated pure magnesium ingot;
the second step is that: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn-Ti, Mg-Mn and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 14.0-15.5% of Gd, 2.8-3.6% of Zn, 0.5-0.8% of Zr, 0.5-1.5% of Nd, 0.3-0.6% of Ti, 0.1-0.5% of Mn and the balance of Mg;
the third step: reducing the temperature of the smelting furnace to 720 ℃, preserving the heat for 1h, stirring, deslagging, standing for 20min, and then pouring the alloy molten liquid into a mold preheated to 200 ℃;
the fourth step: cooling the magnesium alloy casting after pouring and the die in air for 20min, then demoulding, and then cooling in quenching oil;
the fifth step: heating the heat treatment furnace to 480-520 ℃, placing the heat treatment furnace into a magnesium alloy casting, preserving the heat for 8-24h in the protective atmosphere of pyrite, taking out the casting and cooling the casting by water to obtain a solid solution treatment state casting;
and a sixth step: putting the casting subjected to the solution treatment into an oven, heating to 120 ℃ at 100-; and then placing the primary aged casting into an oven, heating to 180-200 ℃, keeping the temperature for 12-14h, taking out, and air-cooling to room temperature to obtain the secondary aged magnesium alloy casting.
As a preferred scheme of the invention, the mass percentages of the elements are as follows: 15.0% of Gd, 2.8% of Zn, 0.5% of Zr, 0.5% of Nd, 0.5% of Ti, 0.3% of Mn and the balance of Mg; in the fifth step, the temperature of the heat treatment furnace is raised to 480 ℃, and the heat is preserved for 24 hours in the protective atmosphere of pyrite; in the sixth step, the heating temperature of the first-stage aging is 100 ℃, and the temperature is kept for 16 h; the heating temperature of the secondary aging is 180 ℃, and the temperature is kept for 14 h.
As a preferred scheme of the invention, the mass percentages of the elements are as follows: 14.0% Gd, 3.6% Zn, 0.6% Zr, 1.0% Nd, 0.6% Ti, 0.5% Mn, the balance Mg; in the fifth step, the temperature of the heat treatment furnace is raised to 500 ℃, and the heat is preserved for 16 hours in the protective atmosphere of pyrite; in the sixth step, the heating temperature of the first-stage aging is 120 ℃, and the temperature is kept for 16 h; the heating temperature of the secondary aging is 200 ℃, and the temperature is kept for 12 h.
As a preferred scheme of the invention, the mass percentages of the elements are as follows: 15.5% of Gd, 2.8% of Zn, 0.8% of Zr, 1.5% of Nd, 0.3% of Ti, 0.1% of Mn and the balance of Mg; in the fifth step, the temperature of the heat treatment furnace is raised to 520 ℃, and the heat is preserved for 8 hours in the protective atmosphere of pyrite; in the sixth step, the heating temperature of the first-stage aging is 110 ℃, and the temperature is kept for 14 h; the heating temperature of the secondary aging is 190 ℃, and the temperature is kept for 12 h.
Compared with the prior art, the invention has the following beneficial effects: the high-performance magnesium alloy prepared by the method has high strength and excellent mechanical property, the tensile yield strength can reach more than 365MPa, the alloy has excellent tension and compression symmetry, and the ratio of the compressive yield strength to the tensile yield strength can be accurately controlled within 1 +/-0.05. Secondly, in the aspect of alloy component design, Nd, Mn and Ti elements are added into the alloy in the current common Mg-Gd-Zn-Zr system, the alloy has uniform structure, and the alloy structure consists of an alpha-Mg matrix phase, an X phase with a long-period stacking ordered (namely LPSO) structure and Mn dispersed and distributed in the X phase2(Nd, Ti) and Mg (Zn, Zr) and Zn dispersed in the matrix2Zr precipitates the phase composition, and the crystal grain edge of the matrix also forms an LPSO structure. Thirdly, in the solution treatment operation, the magnesium alloy casting is heated to a set temperature and enters a furnace after being heated, so that the volume fraction of LPSO in the magnesium alloy is increased, and LPSO structures are formed at the X phase and the grain edge. These LPSO structures can impede dislocation motion when the alloy is deformed by force. And the crystal grain size of the magnesium alloy is small, about 20 mu m, the crystal grain strengthening effect is realized when the magnesium alloy is put into the furnace at a warm temperature, and the LPSO at the crystal grain edge of the matrix is ensured not to be dissolved into the matrix. Mn in a dispersed distribution is formed in the alloy microstructure obtained by the preparation method2(Nd, Ti), Mg (Zn, Zr) and Zn2Zr precipitated phases, which can significantly improve the yield strength of the alloy and act as precipitation strengthening. (iv) fine and dispersed Mg (Zn, Zr) and Zn2Zr is precipitated in the heat treatment process and distributed in the matrix grains, so that dislocation movement can be hindered, and the strength of the alloy is improved. Mn2(Nd, Ti) is distributed in an X phase at the edge of a grain boundary and is used as a heterogeneous nucleation core to play a role in obviously refining grains; and Mn2(Nd, Ti) is also a strengthening phase, and can play a role of pinning dislocation when the material is deformed, so that the mechanics of the material is realizedThe performance is obviously improved. The primary aging temperature is lower than the secondary aging temperature, the primary aging heat preservation time is longer than the secondary aging heat preservation time, the secondary aging can not only improve the yield strength of the alloy, but also effectively reduce the residual stress possibly existing in the casting parts, avoid the deformation or cracking of the workpiece and prolong the service life of the workpiece. The invention can be applied to manufacturing magnesium alloy products such as wing ribs of airplane wings and the like which can not be strengthened by deformation processing means, and other important parts.
Drawings
The invention will be described in further detail with reference to the following drawings and detailed description, which are provided for reference and illustration purposes only and are not intended to limit the invention.
FIG. 1 is a metallographic view of a magnesium alloy obtained in example 1 of the present invention;
FIG. 2 is a metallographic representation of a magnesium alloy obtained in example 3 of the present invention;
FIG. 3 is a gold phase diagram of a magnesium alloy obtained in comparative example 3.
Detailed Description
Example 1
The preparation method of the high-performance magnesium alloy with tension-compression symmetry comprises the following steps in sequence:
the first step is as follows: firstly, 99.99 percent of pure magnesium ingot is put into a heat treatment furnace to be preheated to be dry, then the smelting furnace is heated to 280 ℃, and CO is introduced2+SF6Mixing protective gas, and putting the preheated pure magnesium ingot;
the second step is that: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn-Ti, Mg-Mn and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 15.0% of Gd, 2.8% of Zn, 0.5% of Zr, 0.5% of Nd, 0.5% of Ti, 0.3% of Mn, and the balance of Mg and inevitable impurities, wherein the content of impurities is controlled to be less than 0.05%;
the third step: reducing the temperature of the smelting furnace to 720 ℃, preserving the heat for 1h, stirring, deslagging, standing for 20min, and then pouring the alloy molten liquid into a mold preheated to 200 ℃;
the fourth step: cooling the magnesium alloy casting after pouring and the die in air for 20min, then demoulding, and then cooling in quenching oil;
the fifth step: heating a heat treatment furnace to 480 ℃, putting the magnesium alloy casting into the heat treatment furnace, preserving the heat for 24 hours in the protective atmosphere of pyrite, taking out the casting and cooling the casting by water to obtain a solid solution treatment state casting;
and a sixth step: putting the casting subjected to the solution treatment into an oven, heating to 100 ℃, keeping the temperature for 16h, taking out, and air-cooling to room temperature to obtain a first-stage aged casting; and then placing the casting with the primary aging into an oven, heating to 180 ℃, keeping the temperature for 14h, taking out, and air-cooling to room temperature to obtain the magnesium alloy casting with the secondary aging.
The metallographic structure of the magnesium alloy casting of example 1 is shown in FIG. 1, and the structure thereof is composed of an α -Mg matrix phase, an X phase containing an LPSO structure, and Mn dispersed and distributed in a dispersed manner2(Nd, Ti), Mg (Zn, Zr) and Zn2Zr precipitates the phase composition, and the crystal grain edge of the matrix also forms an LPSO structure.
The magnesium alloy casting of example 1 was subjected to a strength test to obtain a magnesium alloy casting having a compressive yield strength of 373MPa, a tensile yield strength of 365MPa, and a ratio of the compressive yield strength to the tensile yield strength of 1.02.
Comparative example 1
The steps except the alloy composition of the second step were the same as those of example 1, and Mn was removed from the alloy composition of example 1. Second step of comparative example 1: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn-Ti and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 15.0% Gd, 2.8% Zn, 0.5% Zr, 0.5% Nd, 0.5% Ti, and the balance Mg.
The magnesium alloy casting of comparative example 1 was subjected to a strength test to obtain a magnesium alloy casting having a compressive yield strength of 286MPa, a tensile yield strength of 269MPa, and a ratio of the compressive yield strength to the tensile yield strength of 1.06.
Example 2
The preparation method of the high-performance magnesium alloy with tension-compression symmetry comprises the following steps in sequence:
the first step is as follows: firstly, 99.99 percent of pure magnesium ingot is put into a heat treatment furnace to be preheated to be dryThen the smelting furnace is heated to 280 ℃ and CO is introduced2+SF6Mixing protective gas, and putting the preheated pure magnesium ingot;
the second step is that: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn-Ti, Mg-Mn and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 14.0% of Gd, 3.6% of Zn, 0.6% of Zr, 1.0% of Nd, 0.6% of Ti, 0.5% of Mn, and the balance of Mg and inevitable impurities, wherein the content of impurities is controlled to be less than 0.05%;
the third step: reducing the temperature of the smelting furnace to 720 ℃, preserving the heat for 1h, stirring, deslagging, standing for 20min, and then pouring the alloy molten liquid into a mold preheated to 200 ℃;
the fourth step: cooling the magnesium alloy casting after pouring and the die in air for 20min, then demoulding, and then cooling in quenching oil;
the fifth step: heating a heat treatment furnace to 500 ℃, putting a magnesium alloy casting into the heat treatment furnace, preserving heat for 16 hours in a pyrite protective atmosphere, taking out the casting and cooling the casting by water to obtain a solid solution treatment state casting;
and a sixth step: putting the casting subjected to the solution treatment into an oven, heating to 120 ℃, keeping the temperature for 16h, taking out, and air-cooling to room temperature to obtain a first-stage aged casting; and then putting the primary aged casting into an oven, heating to 200 ℃, keeping the temperature for 12h, taking out, and air-cooling to room temperature to obtain the secondary aged magnesium alloy casting.
The magnesium alloy casting of example 2 was subjected to a strength test to obtain a magnesium alloy casting having a compressive yield strength of 407MPa, a tensile yield strength of 416MPa, and a ratio of the compressive yield strength to the tensile yield strength of 0.98.
Comparative example 2
The other steps except the alloy composition of the second step were the same as those of example 2, and Ti element was removed based on the alloy composition of example 2. Second step of comparative example 2: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn, Mg-Mn and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 14.0% Gd, 3.6% Zn, 1.0% Nd, 0.6% Zr, 0.5% Mn, the balance Mg.
The magnesium alloy casting of comparative example 2 was subjected to a strength test to obtain a magnesium alloy casting having a compressive yield strength of 327MPa, a tensile yield strength of 292MPa, and a ratio of the compressive yield strength to the tensile yield strength of 1.12.
Example 3
The preparation method of the high-performance magnesium alloy with tension-compression symmetry comprises the following steps in sequence:
the first step is as follows: firstly, 99.99 percent of pure magnesium ingot is put into a heat treatment furnace to be preheated to be dry, then the smelting furnace is heated to 280 ℃, and CO is introduced2+SF6Mixing protective gas, and putting the preheated pure magnesium ingot;
the second step is that: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn-Ti, Mg-Mn and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 15.5% of Gd, 2.8% of Zn, 0.8% of Zr, 1.5% of Nd, 0.3% of Ti, 0.1% of Mn, and the balance of Mg and inevitable impurities, wherein the content of impurities is controlled to be less than 0.05%;
the third step: reducing the temperature of the smelting furnace to 720 ℃, preserving the heat for 1h, stirring, deslagging, standing for 20min, and then pouring the alloy molten liquid into a mold preheated to 200 ℃;
the fourth step: cooling the magnesium alloy casting after pouring and the die in air for 20min, then demoulding, and then cooling in quenching oil;
the fifth step: heating a heat treatment furnace to 520 ℃, putting the magnesium alloy casting into the heat treatment furnace, preserving the heat for 8 hours in the protective atmosphere of pyrite, taking out the casting and cooling the casting by water to obtain a solid solution treatment state casting;
and a sixth step: putting the casting subjected to the solution treatment into an oven, heating to 110 ℃, keeping the temperature for 14h, taking out, and air-cooling to room temperature to obtain a first-stage aged casting; and then placing the casting with the primary aging into an oven, heating to 190 ℃, keeping the temperature for 12h, taking out, and air-cooling to room temperature to obtain the magnesium alloy casting with the secondary aging.
The metallographic structure of the magnesium alloy casting of example 3 is shown in FIG. 2, and the structure thereof is composed of an α -Mg matrix phase, an X phase containing an LPSO structure, and Mn dispersed and distributed2(Nd, Ti), Mg (Zn, Zr) and Zn2Zr precipitated phase composition and LPSO junction is formed at the edge of matrix crystal grainAnd (5) forming.
The magnesium alloy casting of example 3 was subjected to a strength test to obtain a magnesium alloy casting having a compressive yield strength of 393MPa, a tensile yield strength of 382MPa, and a ratio of the compressive yield strength to the tensile yield strength of 1.03.
Comparative example 3
The steps except the alloy composition of the second step were the same as those of example 3, and Mn and Ti elements were removed on the basis of the alloy composition of example 3. Second step of comparative example 3: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 15.5% of Gd, 2.8% of Zn, 0.8% of Zr, 1.5% of Nd and the balance of Mg.
The magnesium alloy casting of comparative example 3 had a metallographic structure as shown in FIG. 3, and had a structure composed of an α -Mg matrix phase, an X phase containing an LPSO structure, and Mg (Zn, Zr) and Zn dispersed therein2Zr precipitated phase composition, compared with the metallographic structure of example 3, the alloy casting structure is free of Mn2(Nd, Ti) phase, and LPSO structure was not observed at the matrix grain edge, and the grains were significantly coarse (20 μm in scale bar of FIG. 2, 50 μm in scale bar of FIG. 3).
The magnesium alloy casting of comparative example 3 was subjected to a strength test to obtain a magnesium alloy casting having a compressive yield strength of 253MPa, a tensile yield strength of 204MPa, and a ratio of the compressive yield strength to the tensile yield strength of 1.24.
In example 3 and comparative example 3, Mn is contained2Alloy ratio of (Nd, Ti) without Mn2The compressive yield strength and the tensile yield strength of the alloy of (Nd, Ti) are respectively improved by 55.3 percent and 87.3 percent, and the ratio of the compressive yield strength to the tensile yield strength is reduced from 1.24 to 1.03. The matrix phase and the X phase respectively form a dispersion strengthening phase, the structure is obviously refined, and the strength and the tension-compression symmetry of the alloy are obviously improved.
The mechanical properties of examples 1 to 3 and comparative examples 1 to 3 were compared as shown in table 1 below:
the above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention. In addition to the above embodiments, the present invention may have other embodiments. All technical solutions formed by adopting equivalent substitutions or equivalent transformations fall within the protection scope of the claims of the present invention. Technical features of the present invention which are not described may be implemented by or using the prior art, and will not be described herein.
Claims (10)
1. The high-performance magnesium alloy with tension-compression symmetry is characterized by comprising Mg, Gd, Zn, Zr, Nd, Ti and Mn, wherein the mass percentages of the elements are as follows: 14.0-15.5% of Gd, 2.8-3.6% of Zn, 0.5-0.8% of Zr, 0.5-1.5% of Nd, 0.3-0.6% of Ti, 0.1-0.5% of Mn and the balance of Mg.
2. The high-performance magnesium alloy with tension-compression symmetry as claimed in claim 1, wherein the magnesium alloy casting obtained by casting, solution treatment and two-stage aging treatment of the magnesium alloy has a structure comprising an alpha-Mg matrix phase, an X phase containing an LPSO structure and Mn in a dispersed manner2(Nd, Ti), Mg (Zn, Zr) and Zn2Zr precipitates the phase composition, and the crystal grain edge of the matrix also forms an LPSO structure.
3. The high-performance magnesium alloy with tension-compression symmetry as claimed in claim 2, wherein the ratio of the compressive yield strength to the tensile yield strength of the magnesium alloy casting is 1 ± 0.05.
4. The high-performance magnesium alloy with tension-compression symmetry as claimed in claim 1, 2 or 3, wherein the mass percentages of the elements are as follows: 15.0% Gd, 2.8% Zn, 0.5% Zr, 0.5% Nd, 0.5% Ti, 0.3% Mn, the balance Mg.
5. The high-performance magnesium alloy with tension-compression symmetry as claimed in claim 1, 2 or 3, wherein the mass percentages of the elements are as follows: 14.0% Gd, 3.6% Zn, 0.6% Zr, 1.0% Nd, 0.6% Ti, 0.5% Mn, the balance Mg.
6. The high-performance magnesium alloy with tension-compression symmetry as claimed in claim 1, 2 or 3, wherein the mass percentages of the elements are as follows: 15.5% Gd, 2.8% Zn, 0.8% Zr, 1.5% Nd, 0.3% Ti, 0.1% Mn, and the balance Mg.
7. A preparation method of high-performance magnesium alloy with tension-compression symmetry is characterized by sequentially comprising the following steps,
the first step is as follows: firstly, putting a pure magnesium ingot into a heat treatment furnace to be preheated to be dry, then heating a smelting furnace to 280 ℃, and introducing CO2+SF6Mixing protective gas, and putting the preheated pure magnesium ingot;
the second step is that: heating a smelting furnace to 750 ℃, and after a pure magnesium ingot is melted, sequentially adding Mg-Gd, Mg-Nd, Mg-Zn-Ti, Mg-Mn and Mg-Zr intermediate alloys, wherein the mass percentages of the elements are as follows: 14.0-15.5% of Gd, 2.8-3.6% of Zn, 0.5-0.8% of Zr, 0.5-1.5% of Nd, 0.3-0.6% of Ti, 0.1-0.5% of Mn and the balance of Mg;
the third step: reducing the temperature of the smelting furnace to 720 ℃, preserving the heat for 1h, stirring, deslagging, standing for 20min, and then pouring the alloy molten liquid into a mold preheated to 200 ℃;
the fourth step: cooling the magnesium alloy casting after pouring and the die in air for 20min, then demoulding, and then cooling in quenching oil;
the fifth step: heating the heat treatment furnace to 480-520 ℃, placing the heat treatment furnace into a magnesium alloy casting, preserving the heat for 8-24h in the protective atmosphere of pyrite, taking out the casting and cooling the casting by water to obtain a solid solution treatment state casting;
and a sixth step: putting the casting subjected to the solution treatment into an oven, heating to 120 ℃ at 100-; and then placing the primary aged casting into an oven, heating to 180-200 ℃, keeping the temperature for 12-14h, taking out, and air-cooling to room temperature to obtain the secondary aged magnesium alloy casting.
8. The method for preparing the high-performance magnesium alloy with tension-compression symmetry as claimed in claim 7, wherein the mass percentages of the elements are as follows: 15.0% of Gd, 2.8% of Zn, 0.5% of Zr, 0.5% of Nd, 0.5% of Ti, 0.3% of Mn and the balance of Mg;
in the fifth step, the temperature of the heat treatment furnace is raised to 480 ℃, and the heat is preserved for 24 hours in the protective atmosphere of pyrite; in the sixth step, the heating temperature of the first-stage aging is 100 ℃, and the temperature is kept for 16 h; the heating temperature of the secondary aging is 180 ℃, and the temperature is kept for 14 h.
9. The method for preparing the high-performance magnesium alloy with tension-compression symmetry as claimed in claim 7, wherein the mass percentages of the elements are as follows: 14.0% Gd, 3.6% Zn, 0.6% Zr, 1.0% Nd, 0.6% Ti, 0.5% Mn, the balance Mg;
in the fifth step, the temperature of the heat treatment furnace is raised to 500 ℃, and the heat is preserved for 16 hours in the protective atmosphere of pyrite; in the sixth step, the heating temperature of the first-stage aging is 120 ℃, and the temperature is kept for 16 h; the heating temperature of the secondary aging is 200 ℃, and the temperature is kept for 12 h.
10. The method for preparing the high-performance magnesium alloy with tension-compression symmetry as claimed in claim 7, wherein the mass percentages of the elements are as follows: 15.5% of Gd, 2.8% of Zn, 0.8% of Zr, 1.5% of Nd, 0.3% of Ti, 0.1% of Mn and the balance of Mg;
in the fifth step, the temperature of the heat treatment furnace is raised to 520 ℃, and the heat is preserved for 8 hours in the protective atmosphere of pyrite; in the sixth step, the heating temperature of the first-stage aging is 110 ℃, and the temperature is kept for 14 h; the heating temperature of the secondary aging is 190 ℃, and the temperature is kept for 12 h.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0649579A (en) * | 1992-07-01 | 1994-02-22 | Mitsui Mining & Smelting Co Ltd | Gadolinium-containing high-strength magnesium alloy |
| US20100198332A1 (en) * | 2009-01-30 | 2010-08-05 | Bodo Gerold | Implant with a base body of a biocorrodible magnesium alloy |
| CN105543605A (en) * | 2015-12-31 | 2016-05-04 | 重庆大学 | High-strength Mg-Y-Ni-Mn alloy and manufacturing method thereof |
| CN105908040A (en) * | 2016-06-22 | 2016-08-31 | 南昌航空大学 | Mg-Gd-Zn-Ni-Zr rare-earth magnesium alloy for semisolid forming and preparation method for semisolid blank of semisolid Mg-Gd-Zn-Ni-Zr rare-earth magnesium alloy |
| CN109913720A (en) * | 2019-03-27 | 2019-06-21 | 东北大学 | A kind of the high elastic modulus magnesium-based composite material and preparation method of high calcium high aluminium content |
| CN109930045A (en) * | 2019-03-29 | 2019-06-25 | 南京航空航天大学 | High-toughness heat-resistant Mg-Gd alloy and preparation method thereof suitable for gravitational casting |
| CN111235450A (en) * | 2020-01-16 | 2020-06-05 | 西安交通大学 | LPSO phase reinforced degradable high-temperature magnesium alloy and preparation method thereof |
| CN112030042A (en) * | 2020-06-03 | 2020-12-04 | 河海大学 | Gd-containing rare earth magnesium alloy and preparation method thereof |
-
2021
- 2021-09-03 CN CN202111030243.6A patent/CN113699422A/en not_active Withdrawn
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0649579A (en) * | 1992-07-01 | 1994-02-22 | Mitsui Mining & Smelting Co Ltd | Gadolinium-containing high-strength magnesium alloy |
| US20100198332A1 (en) * | 2009-01-30 | 2010-08-05 | Bodo Gerold | Implant with a base body of a biocorrodible magnesium alloy |
| CN105543605A (en) * | 2015-12-31 | 2016-05-04 | 重庆大学 | High-strength Mg-Y-Ni-Mn alloy and manufacturing method thereof |
| CN105908040A (en) * | 2016-06-22 | 2016-08-31 | 南昌航空大学 | Mg-Gd-Zn-Ni-Zr rare-earth magnesium alloy for semisolid forming and preparation method for semisolid blank of semisolid Mg-Gd-Zn-Ni-Zr rare-earth magnesium alloy |
| CN109913720A (en) * | 2019-03-27 | 2019-06-21 | 东北大学 | A kind of the high elastic modulus magnesium-based composite material and preparation method of high calcium high aluminium content |
| CN109930045A (en) * | 2019-03-29 | 2019-06-25 | 南京航空航天大学 | High-toughness heat-resistant Mg-Gd alloy and preparation method thereof suitable for gravitational casting |
| CN111235450A (en) * | 2020-01-16 | 2020-06-05 | 西安交通大学 | LPSO phase reinforced degradable high-temperature magnesium alloy and preparation method thereof |
| CN112030042A (en) * | 2020-06-03 | 2020-12-04 | 河海大学 | Gd-containing rare earth magnesium alloy and preparation method thereof |
Non-Patent Citations (3)
| Title |
|---|
| JIANQIANGHAO ET AL.: "Effects of Ti addition on the formation of LPSO phase and yield asymmetry of Mg-Zn-Y-Mn alloy", 《MATERIALS SCIENCE & ENGINEERING A》 * |
| LI-XIN HONG ET AL.: "Effects of Nd on microstructure and mechanical properties of as-cast Mg-12Gd-2Zn-xNd-0.4Zr alloys with stacking faults", 《INTERNATIONAL JOURNAL OF MINERALS, METALLURGY AND MATERIALS》 * |
| WEI RONG ET AL.: "Effects of Zr and Mn additions on formation of LPSO structure and dynamic recrystallization behavior of Mg-15Gd-1Zn alloy", 《JOURNAL OF ALLOYS AND COMPOUNDS》 * |
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