Preparation method and product of titanium alloy particle reinforced rare earth magnesium-based composite material

Abstract

The application relates to a preparation method of a titanium alloy particle reinforced rare earth magnesium-based composite material and a product, and belongs to the technical field of magnesium alloy materials. The method specifically comprises the following steps: firstly, ball milling TC4 titanium alloy spherical powder and Mg-Gd-Zn-Zr alloy powder under a protective atmosphere to obtain mixed powder; then, hot-pressing sintering the mixed powder in a mold to obtain a blank; and finally, solid-solution and aging treatment of the blank and cooling to room temperature. The TC4 particles are selected as reinforcing bodies, a hot-pressing sintering process and a heat treatment process are combined, and finally, a rare earth magnesium alloy with high comprehensive mechanical properties is prepared. The preparation process is simple, energy consumption is lower, production time is shorter, and the cost is low, which is beneficial to industrialized large-scale production, has a good application prospect and economic benefits.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnesium alloy materials, and in particular relates to a preparation method and product of a titanium alloy particle reinforced rare earth magnesium-based composite material. Background Art

[0002] Magnesium alloys are the lightest metal structural materials currently available, but their absolute strength and stiffness are relatively low compared to other metal structural materials such as steel and aluminum alloys, limiting their application. Due to the solid solution strengthening and precipitation strengthening effects of rare earth elements, rare earth magnesium alloys possess higher strength than conventional magnesium alloys (such as those in the AZ series), potentially meeting the high-strength and lightweight requirements of aerospace and other fields. However, further improvements in the plasticity of rare earth magnesium alloys are needed to enhance their overall mechanical properties while maintaining their strength.

[0003] Adding second-phase particles to alloys can further improve the mechanical properties of the material. Currently, the commonly used second-phase reinforcement particles mainly include non-metallic particles and metallic particles. Non-metallic particles (such as SiC, TiC, Al2O3, TiB2, B4C, AlN, etc.) can effectively improve the strength and stiffness of magnesium alloys, but the plasticity is generally poor. This is because the ceramic particles have poor wettability with the magnesium matrix, making it difficult to form a good interface bond, resulting in high stress concentration at the interface, which leads to premature fracture of the material. Metallic particles (such as Ti particles) have a similar crystal structure to the magnesium matrix and better wettability. They can coordinate matrix deformation, thereby improving the strength of the material without significantly sacrificing plasticity. However, there are relatively few studies on the use of second-phase particles to improve the mechanical properties of rare earth magnesium alloys. It is particularly important to seek second-phase particles that can improve the comprehensive mechanical properties of rare earth magnesium alloys. Summary of the Invention

[0004] In view of this, one of the objects of the present invention is to provide a method for preparing a titanium alloy particle reinforced rare earth magnesium based composite material; a second object is to provide a titanium alloy particle reinforced rare earth magnesium based composite material.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] 1. A method for preparing a titanium alloy particle reinforced rare earth magnesium-based composite material, the preparation method being as follows:

[0007] S1. Ingredients are prepared by mass percentage: 2-10 wt.% of TC4 titanium alloy spherical powder, and the balance is Mg-Gd-Zn-Zr alloy powder. The TC4 titanium alloy spherical powder and the Mg-Gd-Zn-Zr alloy powder are ball-milled under a protective atmosphere to obtain a mixed powder.

[0008] S2, placing the mixed powder in a mold and hot pressing and sintering to obtain a blank;

[0009] S3, solutionizing and aging the blank and then cooling it to room temperature.

[0010] Preferably, in step S1, the mass percentages of the components in the Mg-Gd-Zn-Zr alloy powder are: 5-15 wt.% Gd, 1-2% Zn, 0.1-0.5% Zr, and the balance is Mg and unavoidable impurities.

[0011] Preferably, in step S1, the ball milling under protective atmosphere is specifically: ball milling under argon atmosphere at a ball to material ratio of 5-10:1 and a rotation speed of 50-100 rpm for 3-5 hours.

[0012] Preferably, in step S2, the hot pressing sintering is specifically as follows: placing the mold in a vacuum hot pressing furnace, evacuating the vacuum to less than or equal to 20 Pa, pre-pressurizing the hot pressing head to 5 MPa, then pressurizing it to 80-100 MPa, heating it to 390-420°C at a heating rate of 80-100°C / min, then heating it to 485-495°C at a heating rate of 20-35°C / min, and finally heating it to 500°C at a heating rate of less than or equal to 1°C / min, keeping the temperature and pressure for 5-10 minutes, cooling and releasing the pressure, and cooling it to room temperature.

[0013] Preferably, the cooling is furnace cooling.

[0014] Preferably, in step S3, the solid solution is specifically: solid solution at 480-520° C. for 10-12 hours.

[0015] Preferably, in step S3, the aging is specifically: aging at 200° C. for 1-128 hours.

[0016] Preferably, in step S1, the cooling is water quenching or air cooling.

[0017] Preferably, the particle size of the TC4 titanium alloy spherical powder is less than 25 μm, and the particle size of the Mg-Gd-Zn-Zr alloy powder is 50-100 μm.

[0018] 2. Titanium alloy particle reinforced rare earth magnesium based composite material prepared by the method described.

[0019] The present invention provides a method and product for preparing a titanium alloy particle-reinforced rare earth magnesium-based composite material. In this method, TC4 (Ti-6Al-4V alloy) particles are used as reinforcement. Because titanium and magnesium share a hexagonal structure, magnesium and titanium atoms more readily bond, facilitating the formation of a favorable magnesium-titanium interface. This facilitates load transfer between the magnesium matrix and the titanium particles, reducing material fracture caused by stress concentration at the interface. Furthermore, the load transfer from the magnesium matrix to the titanium particles facilitates the synergistic deformation of the titanium particles, thereby improving the plasticity of the composite material. More importantly, the TC4 particles promote the formation of β-phase and LPSO phases in the rare earth magnesium alloy, resulting in more β-phase and LPSO phases in the rare earth magnesium alloy matrix. These phases dissolve back into the matrix during the subsequent solutionization process, allowing for the precipitation of more nano-precipitated phases during aging. These nano-precipitated phases can hinder dislocation motion during deformation, causing dislocation jamming and leading to work hardening. Furthermore, dislocations bypassing or cutting the nano-precipitated phases require additional energy or stress, thereby increasing the material's strength. By properly controlling the amount of TC4 particles, a uniform distribution of the TC4 particles within the matrix can be ensured, minimizing the tendency of TC4 particles to accumulate within the matrix. Too little TC4 particles can weaken the matrix, while too much prevents uniform dispersion during ball milling, leading to agglomeration of the TC4 particles and deteriorating the mechanical properties of the material. Furthermore, by employing a powder metallurgy process, the TC4 can be uniformly dispersed within the matrix. Using a hot-pressing sintering process, a denser billet can be obtained. Furthermore, the β phase can be present in a more granular form and less in a lattice-like form, resulting in a billet with improved mechanical properties. This is because the β phase precipitates along grain boundaries, forming a network structure that can cause premature fracture along the grain boundaries during deformation, hindering the improvement of the material's mechanical properties. However, the granular β phase can hinder dislocation motion during deformation, thereby improving the material's strength. This preparation process is simple, consumes less energy, and is time-consuming and cost-effective, making it suitable for large-scale industrial production and promising application prospects and economic benefits.

[0020] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0022] Figure 1This is a SEM image of the blank of the titanium alloy particle reinforced rare earth magnesium-based composite material prepared in Example 1 at a magnification of 200 times;

[0023] Figure 2 This is a SEM image of the blank of the titanium alloy particle reinforced rare earth magnesium-based composite material prepared in Example 1 at a magnification of 2000 times;

[0024] Figure 3 This is a SEM image of the blank of the rare earth magnesium-based material prepared in Comparative Example 1 at 2000 times magnification;

[0025] Figure 4 TEM images of the rare earth magnesium-based materials prepared in Example 1 and Comparative Example 1;

[0026] Figure 5 Graph showing the mechanical properties test results of the rare earth magnesium-based materials and their blanks prepared in Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] Example 1

[0029] Preparation of titanium alloy particle reinforced rare earth magnesium matrix composites

[0030] S1. Ingredients by mass percentage: 5 wt.% of TC4 (Ti-6Al-4V) titanium alloy spherical powder with a particle size of less than 25 μm, and the balance of Mg-15Gd-1Zn-0.5Zr alloy powder with a particle size distribution of 50-100 μm. The TC4 titanium alloy spherical powder and the Mg-15Gd-1Zn-0.5Zr alloy powder are mechanically ball-milled at 80 rpm for 5 h in an argon atmosphere at a ball-to-material ratio of 10:1 to obtain a mixed powder;

[0031] S2. Place the mixed powder obtained in step S1 in a graphite mold, then place the mold in a vacuum hot pressing furnace, evacuate to 20 Pa, pre-pressurize the hot pressing head to 5 MPa, then pressurize to 100 MPa, heat to 400°C at a heating rate of 80°C / min, then heat to 495°C at a heating rate of 30°C / min, and finally heat to 500°C at a heating rate of 1°C / min. After keeping the temperature and pressure for 5 minutes, cool and release the pressure, and cool to room temperature with the furnace to obtain a billet;

[0032] S3. Solution-treat the blank obtained in step S2 at 520°C for 12 hours, age at 200°C for 80 hours, and air-cool to room temperature.

[0033] Example 2

[0034] Preparation of titanium alloy particle reinforced rare earth magnesium matrix composites

[0035] S1. Ingredients by mass percentage: 2 wt.% of TC4 (Ti-6Al-4V) titanium alloy spherical powder with a particle size of less than 25 μm, and the balance of Mg-10Gd-2Zn-0.3Zr alloy powder with a particle size distribution of 50-100 μm. The TC4 titanium alloy spherical powder and the Mg-10Gd-2Zn-0.3Zr alloy powder were mechanically ball-milled at a ball-to-material ratio of 5:1 at a speed of 100 rpm for 4 h under an argon atmosphere to obtain a mixed powder;

[0036] S2. Place the mixed powder obtained in step S1 in a graphite mold, then place the mold in a vacuum hot pressing furnace, evacuate to 15 Pa, pre-pressurize the hot pressing head to 5 MPa, then pressurize to 90 MPa, heat to 390°C at a heating rate of 90°C / min, then heat to 485°C at a heating rate of 20°C / min, and finally heat to 500°C at a heating rate of 0.8°C / min. After keeping the temperature and pressure for 8 minutes, cool and release the pressure, and cool to room temperature with the furnace to obtain a billet;

[0037] S3. Solution-treat the blank obtained in step S2 at 480°C for 11 hours, then age at 200°C for 128 hours, and air-cool to room temperature.

[0038] Example 3

[0039] Preparation of titanium alloy particle reinforced rare earth magnesium matrix composites

[0040] S1. Ingredients by mass percentage: 10 wt.% of TC4 (Ti-6Al-4V) titanium alloy spherical powder with a particle size of less than 25 μm, and the balance of Mg-5Gd-1.5Zn-0.1Zr alloy powder with a particle size distribution of 50-100 μm. The TC4 titanium alloy spherical powder and the Mg-5Gd-1.5Zn-0.1Zr alloy powder were mechanically ball-milled at a speed of 50 rpm for 3 h in an argon atmosphere at a ball-to-material ratio of 8:1 to obtain a mixed powder;

[0041] S2. Place the mixed powder obtained in step S1 in a graphite mold, then place the mold in a vacuum hot pressing furnace, evacuate to 10 Pa, pre-pressurize the hot pressing head to 5 MPa, then pressurize to 80 MPa, heat to 420°C at a heating rate of 100°C / min, then heat to 490°C at a heating rate of 35°C / min, and finally heat to 500°C at a heating rate of 0.5°C / min. After keeping the temperature and pressure for 10 minutes, cool and release the pressure, and cool to room temperature with the furnace to obtain a billet;

[0042] S3. Solution-treat the blank obtained in step S2 at 500°C for 10 hours, then age at 200°C for 60 hours, and air-cool to room temperature.

[0043] Comparative Example 1

[0044] The difference from Example 1 is that TC4 (Ti-6Al-4V) titanium alloy spherical powder is not added.

[0045] The blank of the titanium alloy particle reinforced rare earth magnesium based composite material prepared in Example 1 (TC4 / GZ151K blank) was observed by electron scanning microscope at 200 times and 2000 times respectively. Figure 1 and Figure 2 As shown; the blank (GZ151K blank) of the rare earth magnesium-based material prepared in Comparative Example 1 was observed at 2000 times, and the results were as follows Figure 3 As shown. Figure 1 It can be seen that the spherical TC4 particles in the TC4 / GZ151K billet are evenly distributed in the matrix without any agglomeration phenomenon, and the interface between TC4 and the magnesium matrix is ​​well bonded, the matrix has no obvious gaps or cavities, and no coarse chain-like second phase is precipitated. Figure 2 and Figure 3 The results of the β phase and LPSO phase in TC4 / GZ151K and GZ151K billets are shown in Table 1. Figure 2 、 Figure 3 As can be seen from Table 1, the amount of β phase and LPSO phase in the TC4 / GZ151K billet is significantly greater than that in the GZ151K billet. In addition, there are many granular β phases, a few grid-like β phases, and a large number of lamellar LPSO structures in the TC4 / GZ151K billet, indicating that the addition of TC4 particles can promote the precipitation of β phase and LPSO structure.

[0046] Table 1 Statistical results of β phase and LPSO phase in the blanks of rare earth magnesium-based materials prepared in Example 1 and Comparative Example 1

[0047]

[0048] The rare earth magnesium-based materials prepared in Example 1 and Comparative Example 1 were tested using a transmission electron microscope. The results are as follows: Figure 4 As shown in Table 2, Figure 4 It can be seen that the rare earth magnesium-based material (TC4 / GZ151K) prepared in Example 1 has more, more dispersed, and finer nano-precipitated phases (β' precipitated phases) precipitated in the matrix compared to the rare earth magnesium-based material (GZ151K) prepared in Comparative Example 1. In addition, as shown in Table 2, the areal number density and area ratio of the β' precipitated phase in TC4 / GZ151K are both higher than those in GZ151K, further indicating that TC4 / GZ151K has a larger number of β' precipitated phases.

[0049] Table 2 Statistical results of β′ precipitation phase in rare earth magnesium-based materials prepared in Example 1 and Comparative Example 1

[0050]

[0051] The mechanical properties of the rare earth magnesium-based materials and blanks prepared in Example 1 and Comparative Example 1 were tested respectively. The results are as follows: Figure 5 As shown in Table 3, Figure 5 As shown in Table 3, the TC4 / GZ151K billet exhibits superior plasticity and strength to that of the GZ151K billet. While the strength of the TC4 / GZ151K billet is superior to that of the GZ151K billet, its plasticity, though slightly inferior, is still relatively high overall. During sintering, TC4 particles promote the precipitation of β phase and LPSO structure. The TC4 / GZ151K billet contains numerous granular β phases, a small amount of lattice-like β phases, and a large amount of lamellar LPSO structure, resulting in improved strength and plasticity. After solution and aging treatments, the β phase and LPSO structure in the billet transform into nano-precipitates. These nano-precipitates hinder dislocation motion during deformation, causing dislocation jamming and thus strain hardening. Furthermore, dislocations bypassing or cutting through the nano-precipitates require additional energy or stress, thereby increasing the material's strength. Since the plasticity of TC4 / GZ151K is sacrificed while the strength is improved, the plasticity of TC4 / GZ151K is slightly lower than that of GZ151K. However, the addition of TC4 particles can form a good magnesium-titanium interface, which is beneficial to the transfer of load between the magnesium matrix and titanium particles, thereby facilitating the synergistic deformation effect of titanium particles, and ultimately enabling TC4 / GZ151K to maintain a relatively high plasticity.

[0052] Table 3 Mechanical property test results of rare earth magnesium-based materials and blanks prepared in Example 1 and Comparative Example 1

[0053]

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a titanium alloy particle reinforced rare earth magnesium-based composite material, characterized in that: The preparation method is as follows: S1. Ingredients are prepared by mass percentage: 2-10 wt.% of TC4 titanium alloy spherical powder and the balance of Mg-Gd-Zn-Zr alloy powder; and the TC4 titanium alloy spherical powder and the Mg-Gd-Zn-Zr alloy powder are ball-milled under a protective atmosphere to obtain a mixed powder. S2. placing the mixed powder in a mold and hot pressing and sintering to obtain a blank; the hot pressing and sintering specifically comprises: placing the mold in a vacuum hot pressing furnace, evacuating the mold to a vacuum level of less than or equal to 20 Pa, pre-pressing the hot pressing head to 5 MPa, then pressurizing it to 80-100 MPa, heating it to 390-420°C at a heating rate of 80-100°C / min, then heating it to 485-495°C at a heating rate of 20-35°C / min, and finally heating it to 500°C at a heating rate of less than or equal to 1°C / min, maintaining the temperature and pressure for 5-10 minutes, then cooling it down, releasing the pressure, and cooling it to room temperature; S3, solutionizing and aging the blank and then cooling it to room temperature.

2. The preparation method according to claim 1, wherein In step S1 , the mass percentages of the components in the Mg—Gd—Zn—Zr alloy powder are: 5-15 wt.% Gd, 1-2% Zn, 0.1-0.5% Zr, and the balance is Mg and unavoidable impurities.

3. The preparation method according to claim 1, wherein In step S1, the ball milling under protective atmosphere specifically includes: ball milling under argon atmosphere at a ball-to-material ratio of 5-10:1 and a rotation speed of 50-100 rpm for 3-5 hours.

4. The preparation method according to claim 1, wherein In step S2, the cooling is furnace cooling.

5. The preparation method according to claim 1, wherein In step S3, the solid solution is specifically: solid solution at 480-520° C. for 10-12 hours.

6. The preparation method according to claim 1, wherein In step S3, the aging is specifically: aging at 200° C. for 1-128 hours.

7. The preparation method according to claim 1, wherein In step S3, the cooling is water quenching or air cooling.

8. The preparation method according to any one of claims 1 to 7, wherein The particle size of the TC4 titanium alloy spherical powder is less than 25 μm, and the particle size of the Mg-Gd-Zn-Zr alloy powder is 50-100 μm.

9. A titanium alloy particle reinforced rare earth magnesium based composite material prepared by the preparation method according to any one of claims 1 to 8.

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