TC4 reinforced rare earth magnesium-based composite material as well as preparation method and application thereof

Abstract

The invention discloses a TC4 reinforced rare earth magnesium-based composite material as well as a preparation method and application thereof, and belongs to the technical field of magnesium-based composite materials. The preparation method of the TC4 reinforced rare earth magnesium-based composite material comprises the following steps: adding preheated TC4 particles into a rare earth magnesium alloy melt with the temperature of 660-690 DEG C in batches, stirring and dispersing after adding in each batch, and then adding the TC4 particles in the next batch; after all the TC4 particles are added, the temperature is increased to 715-725 DEG C for a first ultrasonic stage, and then the temperature is decreased to 645-655 DEG C for a second ultrasonic stage; after the second ultrasonic stage is finished, naturally cooling to 615-625 DEG C, and then carrying out water cooling; the TC4 particles are non-spherical particles with the particle size ranging from 25 micrometers to 100 micrometers. According to the method, the magnesium-based composite material with relatively good rigidity, strength and plasticity can be obtained, and the magnesium-based composite material can be used for preparing low-altitude flight parts, aerospace parts or new energy automobile parts and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of magnesium-based composite materials, and in particular to a TC4-reinforced rare earth magnesium-based composite material and a preparation method and application thereof. Background Art

[0002] As a lightweight metal structural material, magnesium has good specific stiffness, specific strength, damping performance and electromagnetic shielding performance, and can be widely used in 3C electronic products, transportation, aerospace and other fields. However, the absolute strength and absolute stiffness of magnesium are weaker than those of metal materials such as aluminum and steel, which limits its application range. At present, some existing technologies improve the strength and stiffness of magnesium alloys by adding reinforcing phases such as ceramics and carbon fibers to magnesium alloys, but these reinforcing phases are not coherent with the magnesium matrix interface and are brittle, resulting in the deterioration of plasticity while the strength of the composite material is improved.

[0003] At present, there is no magnesium-based composite material with good stiffness, strength and plasticity.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a TC4 reinforced rare earth magnesium-based composite material and a preparation method and application thereof, so as to solve or improve the above technical problems.

[0006] The present invention can be implemented like this: In a first aspect, the present invention provides a method for preparing a TC4-reinforced rare earth magnesium-based composite material, comprising the following steps: adding preheated TC4 particles to a rare earth magnesium alloy melt at a temperature of 660° C. to 690° C. in batches, stirring and dispersing each batch before adding the next batch of TC4 particles; after all the TC4 particles are added, heating to 715° C. to 725° C. for a first ultrasonic stage, then cooling to 645° C. to 655° C. for a second ultrasonic stage; after the second ultrasonic stage is completed, naturally cooling to 615° C. to 625° C., then water cooling; TC4 particles are non-spherical particles, and the particle size of TC4 particles is 25μm~100μm.

[0007] In an optional embodiment, the mass of the TC4 particles added at a single time accounts for 20% to 50% of the total mass of the TC4 particles added in advance; The total mass of the added TC4 particles is preset to be 0.5% to 15% of the mass of the TC4-reinforced rare earth magnesium-based composite material.

[0008] In an optional embodiment, the TC4 particles are preheated at 150° C. to 250° C. for 1 h to 1.5 h.

[0009] In an optional embodiment, the stirring dispersion is carried out at 400 r / min to 600 r / min for 5 min to 10 min.

[0010] In an optional embodiment, the ultrasonic powers of the first ultrasonic stage and the second ultrasonic stage are independently 19.5Kw~20.0Kw, the ultrasonic time of the first ultrasonic stage is 3min~5min, and the ultrasonic time of the second ultrasonic stage is 0.5min~2min.

[0011] In an optional embodiment, the method further includes: subjecting the water-cooled product to a solution treatment and an extrusion process; Among them, the solution treatment is carried out at 480℃~520℃ for 8h~12h; The extrusion process is carried out at a temperature of 450°C to 500°C, an extrusion ratio of 10:1 to 40:1, and an extrusion speed of 0.45 mm / min to 0.55 mm / min.

[0012] In a second aspect, the present invention provides a TC4 reinforced rare earth magnesium-based composite material, which is prepared by the preparation method of any one of the aforementioned embodiments.

[0013] In an optional embodiment, the TC4 enhanced rare earth magnesium based composite material has at least one of the following characteristics: Feature 1: TC4 particles are dispersed in the rare earth magnesium alloy; Feature 2: The mass proportion of Mg in the rare earth magnesium alloy is 85%~90%, and the mass proportion of rare earth is 12%~14%; the rare earth includes at least one of Gd and Y.

[0014] In an alternative embodiment, the rare earth magnesium alloy is an alloy containing Mg, Gd, Y, Zn and Zr.

[0015] In a third aspect, the present invention provides an application of a TC4-reinforced rare earth magnesium-based composite material according to any of the aforementioned embodiments, which can be used, for example, to prepare low-altitude flight components, aerospace components, or new energy vehicle components.

[0016] The beneficial effects of the present invention include: The present invention achieves uniform dispersion of TC4 particles in the rare earth magnesium alloy melt by adding TC4 particles into the rare earth magnesium alloy melt, combining stirring and double-stage ultrasound; the casting process is naturally cooled to a semi-solid state and then water-cooled, thereby achieving uniform dispersion of TC4 particles in the structure and fine grains.

[0017] During the preparation process, non-spherical TC4 particles are specifically used, which are more likely to deform during processing, which is beneficial to improving the performance of the composite material. By specifically using micron-level TC4 particles, the problem of nano-level TC4 particles being very flammable under the protective atmosphere during the smelting process due to their high energy is avoided. That is, by controlling the morphology and particle size of TC4 particles, the TC4 particles are effectively compounded with the rare earth magnesium alloy melt by the smelting method.

[0018] The TC4 reinforced rare earth magnesium-based composite material prepared by the method of the present invention has high tensile strength, yield strength, elongation and stiffness, and can be used to prepare low-altitude flight parts, aerospace parts or new energy vehicle parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 This is a SEM image of the cast TC4 reinforced rare earth magnesium-based composite material provided in Example 1 of the present invention; Figure 2 This is a microstructure diagram of the TC4 reinforced rare earth magnesium-based composite rod after extrusion in Example 1 of the present invention; Figure 3 for Figure 2 A partial enlarged view of Figure 4 This is a graph showing the electron backscatter diffraction test results of the TC4 enhanced rare earth magnesium-based composite rod provided in Example 1 of the present invention; Figure 5 This is the tensile curve of the TC4 reinforced rare earth magnesium-based composite rod provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0022] The TC4 reinforced rare earth magnesium-based composite material provided by the present invention and its preparation method and application are described in detail below.

[0023] It should be noted that TC4 and magnesium are both active metals. The density of TC4 is greater than that of magnesium, which makes TC4 prone to sedimentation, burning and oxidation. In addition, if conventional preparation methods (such as powder metallurgy) are used to mix TC4 and magnesium-based materials, there is a risk of explosion in the process. Therefore, TC4 is generally not used in the field of magnesium alloy composite materials.

[0024] However, TC4 particles have high stiffness and plasticity, and good wettability with magnesium. If TC4 particles and magnesium-based materials can be effectively compounded into composite materials, it will be beneficial to improve the stiffness and plasticity of magnesium-based materials.

[0025] Based on this, the present invention creatively proposes a method for preparing a TC4 reinforced rare earth magnesium-based composite material, thereby achieving effective composite of TC4 particles and magnesium-based materials.

[0026] The method comprises the following steps: adding preheated TC4 particles into a rare earth magnesium alloy melt at a temperature of 660°C-690°C in batches, stirring and dispersing each batch before adding the next batch of TC4 particles; after all the TC4 particles are added, heating to 715°C-725°C for a first ultrasonic stage, then cooling to 645°C-655°C for a second ultrasonic stage; after the second ultrasonic stage is completed, naturally cooling to 615°C-625°C, then water cooling.

[0027] By adding TC4 particles into the rare earth magnesium alloy melt, combined with stirring and double-stage ultrasound, the uniform dispersion of TC4 particles in the rare earth magnesium alloy melt is achieved; the casting process is naturally cooled to a semi-solid state and then water-cooled, so that the TC4 particles in the organization are evenly dispersed and the grains are fine.

[0028] In the present invention, the TC4 particles are non-spherical particles, and the particle size of the TC4 particles is 25 μm to 100 μm.

[0029] It should be noted that in the prior art, TC4 particles are usually spherical particles, but spherical particles are not easily deformed during processing, which is not conducive to the performance improvement of magnesium-based composite materials. The present invention specifically uses non-spherical TC4 particles, which are more easily deformed during processing and can be elongated along the extrusion direction during extrusion, thereby improving the performance of the composite material. In addition, the present invention also specifically uses micron-level TC4 particles to avoid the problem that nano-level TC4 particles are very flammable under the protective atmosphere during the smelting process due to their excessive energy. That is, the present invention controls the morphology and particle size of TC4 particles to achieve effective compounding of TC4 particles with rare earth magnesium alloy melts using a smelting method.

[0030] In some optional embodiments, the preparation of the rare earth magnesium alloy melt may include: melting the rare earth magnesium alloy, refining and standing it, and then cooling it to 660°C~690°C (such as 660°C, 665°C, 670°C, 675°C, 680°C, 685°C or 690°C, etc.).

[0031] The mass proportion of Mg in the rare earth magnesium alloy may be 85% to 90% (e.g., 85%, 86%, 87%, 88%, 89% or 90%), and the mass proportion of rare earth may be 12% to 14% (e.g., 12%, 13% or 14%). Rare earth may illustratively include at least one of Gd and Y.

[0032] In some typical embodiments, the rare earth magnesium alloy is an alloy containing Mg, Gd, Y, Zn and Zr, wherein the mass proportion of Gd and Y in the rare earth magnesium alloy is 13wt%, specifically, the mass proportion of Gd is 9%, and the mass proportion of Y is 4%.

[0033] In some optional embodiments, the TC4 particles can be preheated at 150°C to 250°C (such as 150°C, 180°C, 200°C, 220°C or 250°C, etc.) for 1h to 1.5h (such as 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, etc.).

[0034] By preheating the TC4 particles before adding them to the rare earth magnesium alloy melt, it is beneficial to reduce the temperature difference between the TC4 particles and the melt, and achieve rapid and uniform dispersion of the TC4 particles. If the preheating temperature is too low, it is not conducive to the rapid dispersion of the TC4 particles; if the preheating temperature is too high, it is easy to cause the TC4 particles to oxidize, which is not conducive to the interface bonding with the magnesium melt, resulting in reduced performance of the composite material.

[0035] In some optional embodiments, the mass of TC4 particles added at a single time may account for 20% to 50% of the total mass of TC4 particles added in advance, such as 20%, 25%, 30%, 35%, 40%, 45% or 50%, etc., or other values ​​within the range of 20% to 50%.

[0036] By adding the preheated TC4 particles into the rare earth magnesium alloy melt in batches, it is more conducive to uniform dispersion of the TC4 particles in the rare earth magnesium alloy melt than adding them all at once.

[0037] The total mass of the TC4 particles to be added can be 0.5% to 15% of the mass of the TC4-enhanced rare earth magnesium-based composite material, such as 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%, etc., or other values ​​within the range of 0.5% to 15%. In some typical embodiments, the total mass of the TC4 particles to be added can be 2% to 8% of the mass of the TC4-enhanced rare earth magnesium-based composite material. In some more typical embodiments, the total mass of the TC4 particles to be added is 5% of the mass of the TC4-enhanced rare earth magnesium-based composite material.

[0038] If the total mass of TC4 particles accounts for too large a proportion in the TC4-reinforced rare earth magnesium-based composite material (such as 18%), it is easy to cause agglomeration and sedimentation of TC4 particles, increase the pores and inclusions in the composite material, and lead to a decrease in the strength and plasticity of the composite material.

[0039] In some optional embodiments, stirring and dispersing can be carried out at 400 r / min~600 r / min (such as 400 r / min, 450 r / min, 500 r / min, 550 r / min or 600 r / min, etc.) for 5 min~10 min (such as 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, etc.).

[0040] In the present invention, after all the TC4 particles are added, the entire mixed system is first heated to 715°C-725°C for the first ultrasonic stage, and then cooled to 645°C-655°C for the second ultrasonic stage.

[0041] Among them, the temperature of the first ultrasonic stage can be 715℃, 716℃, 717℃, 718℃, 719℃, 720℃, 721℃, 722℃, 723℃, 724℃ or 725℃, etc., or other values ​​within the range of 715℃~725℃.

[0042] The temperature of the second ultrasonic stage can be 645°C, 646°C, 647°C, 648°C, 649°C, 650°C, 651°C, 652°C, 653°C, 654°C or 655°C, etc., or other values ​​within the range of 645°C to 655°C.

[0043] The first ultrasonic stage is mainly used to disperse the TC4 particles. The reason why the temperature of the mixed system is increased in the first ultrasonic stage is to increase the fluidity of the melt and promote the uniform dispersion of the TC4 particles under the action of ultrasound. The second ultrasonic stage is mainly used to remove impurities in the melt. The reason why the temperature of the mixed system is reduced in the second ultrasonic stage is to reduce the melt viscosity and promote the sedimentation of impurities in the melt.

[0044] In some optional embodiments, the ultrasonic powers of the first ultrasonic stage and the second ultrasonic stage can independently be 19.5Kw~20.0Kw, such as 19.5Kw, 19.6Kw, 19.7Kw, 19.8Kw, 19.9Kw or 20.0Kw, etc., or other values ​​within the range of 19.5Kw~20.0Kw.

[0045] In some optional embodiments, the ultrasound time of the first ultrasound stage may be 3 min to 5 min, such as 3 min, 3.5 min, 4 min, 4.5 min or 5 min, or other values ​​within the range of 3 min to 5 min.

[0046] The ultrasonic time of the second ultrasonic stage may be 0.5 min to 2 min, such as 0.5 min, 1 min, 1.5 min or 2 min, or may be other values ​​within the range of 0.5 min to 2 min.

[0047] In the present invention, after the second ultrasonic stage is completed, the mixed system is first cooled to 615°C~625°C (such as 615°C, 618°C, 620°C, 622°C or 625°C, etc.) by natural cooling, so that the mixed system can be semi-solid, and then water-cooled, which can achieve uniform dispersion of TC4 particles in the tissue and obtain fine grains.

[0048] Furthermore, the preparation method of the TC4 reinforced rare earth magnesium-based composite material of the present invention further comprises: subjecting the water-cooled product to solid solution treatment and extrusion processing.

[0049] The solution treatment may be carried out at 480°C to 520°C (such as 480°C, 490°C, 500°C, 510°C or 520°C, etc.) for 8h to 12h (such as 8h, 9h, 10h, 11h or 12h, etc.).

[0050] The extrusion process can be carried out at a temperature of 450°C to 500°C (such as 450°C, 460°C, 470°C, 480°C, 490°C or 500°C), an extrusion ratio of 10:1 to 40:1 (such as 10:1, 15:1, 20:1, 25:1, 30:1, 35:1 or 40:1), and an extrusion speed of 0.45mm / min to 0.55mm / min (such as 0.45mm / min, 0.50mm / min or 0.55mm / min).

[0051] It should be noted that the present invention uses non-spherical TC4 particles. During the extrusion process, the TC4 particles can be elongated along the extrusion direction, and the synergistic strengthening of the composite material can be achieved through the cooperation with the LPSO precipitated phase and the rare earth magnesium alloy matrix.

[0052] Correspondingly, the present invention also provides a TC4 reinforced rare earth magnesium-based composite material, which is prepared by the above-mentioned preparation method.

[0053] Compared with the composite materials obtained by ceramic particle reinforcement phase, which have the problems of low plasticity and high brittleness, the TC4 reinforced rare earth magnesium-based composite material provided by the present invention has good wettability at the interface between TC4 particles and rare earth magnesium matrix, which effectively improves the strength, stiffness and plasticity of the composite material.

[0054] In the TC4 reinforced rare earth magnesium based composite material, TC4 particles are dispersed in the rare earth magnesium alloy.

[0055] Taking the total mass of the preset TC4 particles added as 5% of the mass of the TC4-reinforced rare earth magnesium-based composite material as an example, the corresponding TC4-reinforced rare earth magnesium-based composite material has a tensile strength of 458 MPa, a yield strength of 393 MPa, an elongation of 12.4%, and a stiffness of 51.5 GPa.

[0056] In addition, the present invention also provides an application of the above-mentioned TC4 reinforced rare earth magnesium-based composite material, for example, it can be used to prepare low-altitude flight components, aerospace components or new energy vehicle components.

[0057] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0058] Example 1 This embodiment provides a TC4 reinforced rare earth magnesium-based composite material, and the preparation method thereof includes: S1: melting the rare earth magnesium alloy, refining and standing it, and then cooling it to 680° C. to obtain a rare earth magnesium alloy melt.

[0059] Among them, the main components of rare earth magnesium alloy are Mg, Gd, Y, Zn and Zr. The mass percentage of Gd in the rare earth magnesium alloy is 9%, the mass percentage of Y in the rare earth magnesium alloy is 4%, the mass percentage of Mg in the rare earth magnesium alloy is 86%, and the remainder is Zn, Zr and unavoidable impurities.

[0060] S2: Preheat the TC4 particles at 200°C for 1h, and add the preheated TC4 particles in batches to the rare earth magnesium alloy melt at a temperature of 680°C. The mass of the TC4 particles added at a single time is 25% of the total mass of the TC4 particles added at a preset time, and the total mass of the TC4 particles added at a preset time is 5% of the mass of the TC4-reinforced rare earth magnesium-based composite material. After adding the TC4 particles at a single time, stir at a speed of 500r / min for 10min, and then add the next batch of TC4 particles (the temperature of the entire adding process is maintained at 680°C).

[0061] Among them, TC4 particles are non-spherical particles with a particle size of 25μm~100µm.

[0062] S3: After all the TC4 particles were added, the mixed system was heated to 720°C for the first ultrasonic stage, the ultrasonic power of which was 19.8Kw and the ultrasonic time was 4min. Then the temperature was lowered to 650°C for the second ultrasonic stage, the ultrasonic power of which was 19.8Kw and the ultrasonic time was 1min.

[0063] S4: After the second ultrasonic stage, the temperature is naturally reduced to 620°C, followed by water cooling.

[0064] S5: The water-cooled product was solution treated at 500°C for 10 h, and then a cylindrical sample was cut and extruded into a rod at an extrusion temperature of 450°C, an extrusion ratio of 36:1, and an extrusion speed of 0.5 mm / min.

[0065] Example 2 This embodiment provides a TC4 reinforced rare earth magnesium-based composite material, and the preparation method thereof includes: S1: melt the rare earth magnesium alloy, refine and stand it, then cool it to 660°C to obtain a rare earth magnesium alloy melt.

[0066] Among them, the main components of rare earth magnesium alloy are Mg, Gd, Y, Zn and Zr. The mass percentage of Gd in the rare earth magnesium alloy is 9%, the mass percentage of Y in the rare earth magnesium alloy is 4%, the mass percentage of Mg in the rare earth magnesium alloy is 86%, and the remainder is Zn, Zr and unavoidable impurities.

[0067] S2: Preheat the TC4 particles at 150°C for 1.5h, and add the preheated TC4 particles in batches to the rare earth magnesium alloy melt at a temperature of 660°C. The mass of the TC4 particles added at a single time is 50% of the total mass of the TC4 particles added at a preset time, and the total mass of the TC4 particles added at a preset time is 0.5% of the mass of the TC4-reinforced rare earth magnesium-based composite material. After adding the TC4 particles at a single time, stir at a speed of 400r / min for 10min, and then add the next batch of TC4 particles (the temperature of the entire adding process is maintained at 660°C).

[0068] Among them, TC4 particles are non-spherical particles with a particle size of 25μm~100µm.

[0069] S3: After all the TC4 particles were added, the mixed system was heated to 715°C for the first ultrasonic stage, the ultrasonic power of which was 19.5Kw and the ultrasonic time was 5min. Then the temperature was lowered to 645°C for the second ultrasonic stage, the ultrasonic power of which was 19.5Kw and the ultrasonic time was 2min.

[0070] S4: After the second ultrasonic stage, the temperature is naturally reduced to 615°C, followed by water cooling.

[0071] S5: The water-cooled product was solution treated at 480°C for 12 h, and then a cylindrical sample was cut and extruded into a rod at an extrusion temperature of 475°C, an extrusion ratio of 10:1, and an extrusion speed of 0.45 mm / min.

[0072] Example 3 This embodiment provides a TC4 reinforced rare earth magnesium-based composite material, and the preparation method thereof includes: S1: melt the rare earth magnesium alloy, refine and let stand, then cool to 690°C to obtain a rare earth magnesium alloy melt.

[0073] Among them, the main components of rare earth magnesium alloy are Mg, Gd, Y, Zn and Zr. The mass percentage of Gd in the rare earth magnesium alloy is 9%, the mass percentage of Y in the rare earth magnesium alloy is 4%, the mass percentage of Mg in the rare earth magnesium alloy is 86%, and the remainder is Zn, Zr and unavoidable impurities.

[0074] S2: Preheat the TC4 particles at 250°C for 1 hour, and add the preheated TC4 particles in batches to the rare earth magnesium alloy melt at a temperature of 690°C. The mass of the TC4 particles added at a single time is 20% of the total mass of the TC4 particles added at a preset time, and the total mass of the TC4 particles added at a preset time is 15% of the mass of the TC4-reinforced rare earth magnesium-based composite material. After adding the TC4 particles at a single time, stir at a speed of 600r / min for 5 minutes, and then add the next batch of TC4 particles (the temperature of the entire adding process is maintained at 690°C).

[0075] Among them, TC4 particles are non-spherical particles with a particle size of 25μm~100µm.

[0076] S3: After all the TC4 particles are added, the mixed system is heated to 725°C for the first ultrasonic stage, the ultrasonic power of which is 20.0Kw and the ultrasonic time is 3min. Then the temperature is lowered to 655°C for the second ultrasonic stage, the ultrasonic power of which is 20.0Kw and the ultrasonic time is 0.5min.

[0077] S4: After the second ultrasonic stage, the temperature is naturally reduced to 625°C, followed by water cooling.

[0078] S5: The water-cooled product was solution treated at 520°C for 8 h, and then a cylindrical sample was cut and extruded into a rod at an extrusion temperature of 500°C, an extrusion ratio of 40:1, and an extrusion speed of 0.55 mm / min.

[0079] Comparative Example 1 The difference between this comparative example and Example 1 is that the TC4 particles are spherical particles.

[0080] Comparative Example 2 The difference between this comparative example and Example 1 is that the particle size of TC4 particles is 1 nm to 1.2 nm.

[0081] Comparative Example 3 The difference between this comparative example and Example 1 is that the TC4 particles are directly added into the rare earth magnesium alloy melt in batches without preheating.

[0082] Comparative Example 4 The difference between this comparative example and Example 1 is that TC4 particles are added into the rare earth magnesium alloy melt at one time.

[0083] Comparative Example 5 The difference between this comparative example and Example 1 is that after all the TC4 particles are added, no ultrasonic treatment is performed and the temperature is directly cooled naturally.

[0084] Comparative Example 6 The difference between this comparative example and Example 1 is that the ultrasonic stage only has the first ultrasonic stage.

[0085] Comparative Example 7 The difference between this comparative example and Example 1 is that the ultrasonic stage only has the second ultrasonic stage.

[0086] Comparative Example 8 The difference between this comparative example and Example 1 is that the total mass of the TC4 particles added is preset to be 18% of the mass of the TC4-reinforced rare earth magnesium-based composite material.

[0087] Test example ①. Taking Example 1 as an example, the following tests were performed on the TC4 reinforced rare earth magnesium-based composite rod prepared in this example: A. The microstructure of the cast TC4 reinforced rare earth magnesium-based composite material was observed, and the results are as follows: Figure 1 shown.

[0088] By Figure 1It can be seen that the TC4 particles in the composite material are uniformly dispersed, and the as-cast grains are significantly smaller than the as-cast structure of conventional casting.

[0089] B. The microstructure of the extruded TC4 reinforced rare earth magnesium-based composite rod was observed, and the results are as follows Figure 2 and Figure 3 As shown. Figure 2 and Figure 3 It can be seen that the TC4 particles are distributed in streamlines along the extrusion direction, and the TC4 particles are elongated along the extrusion direction.

[0090] C. The TC4 enhanced rare earth magnesium based composite rod was subjected to an electron backscatter diffraction test, and the results are as follows: Figure 4 shown.

[0091] Depend on Figure 4 It can be seen that the composite material is composed of fine recrystallized grains and coarse unrecrystallized grains, and the unidentified phases are the second phase particles and TC4 particles.

[0092] ②. The TC4 reinforced rare earth magnesium-based composite rods obtained in the above Examples 1 to 3 and Comparative Examples 1 to 8 were subjected to performance tests, wherein the tensile strength, yield strength and elongation were tested with reference to GB228-2021, and the stiffness was tested with reference to GB228-2021. The test results are shown in Tables 1 and Figure 5 shown.

[0093] Table 1 Test results

[0094] It can be seen from Table 1 that the TC4 reinforced rare earth magnesium-based composite material prepared by the preparation method provided in the embodiments of the present invention has high tensile strength, yield strength, elongation and stiffness, among which the scheme in Embodiment 1 is the best.

[0095] By comparing Example 1 with Comparative Examples 1 to 8, it can be seen that when the preparation process or conditions change, the prepared TC4 reinforced rare earth magnesium-based composite material will be inferior in certain properties.

[0096] In summary, the present invention creatively proposes a method for preparing a TC4 reinforced rare earth magnesium-based composite material, which realizes the effective compounding of TC4 particles and rare earth magnesium-based materials. The obtained composite material has better stiffness, strength and plasticity, and can be used to prepare low-altitude flight components, aerospace components or new energy vehicle components, etc.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a TC4-reinforced rare earth magnesium-based composite material, characterized in that: The following steps are involved: Preheated TC4 particles are added to a rare earth magnesium alloy melt at a temperature of 660°C to 690°C in batches, and each batch is stirred and dispersed before adding the next batch of TC4 particles; after all TC4 particles are added, the temperature is raised to 715°C to 725°C for the first ultrasonic stage, and then the temperature is lowered to 645°C to 655°C for the second ultrasonic stage; After the second ultrasonic stage, the temperature was naturally cooled to 615℃~625℃, followed by water cooling; The TC4 particles are non-spherical particles, and the particle size of the TC4 particles is 25 μm to 100 μm.

2. The preparation method according to claim 1, characterized in that: The mass of TC4 particles added at a time accounts for 20% to 50% of the total mass of TC4 particles added in advance; The total mass of the TC4 particles added is preset to be 0.5% to 15% of the mass of the TC4-reinforced rare earth magnesium-based composite material.

3. The preparation method according to claim 1, characterized in that: The TC4 particles are preheated at 150° C. to 250° C. for 1 h to 1.5 h.

4. The preparation method according to claim 1, characterized in that: The stirring and dispersion is carried out at 400 r / min~600 r / min for 5 min~10 min.

5. The preparation method according to claim 1, characterized in that: The ultrasonic powers of the first ultrasonic stage and the second ultrasonic stage are independently 19.5Kw~20.0Kw, the ultrasonic time of the first ultrasonic stage is 3min~5min, and the ultrasonic time of the second ultrasonic stage is 0.5min~2min.

6. The preparation method according to claim 1, characterized in that: Also includes: The water-cooled product is subjected to solution treatment and extrusion processing; Among them, the solution treatment is carried out at 480℃~520℃ for 8h~12h; The extrusion process is carried out at a temperature of 450°C to 500°C, an extrusion ratio of 10:1 to 40:1, and an extrusion speed of 0.45 mm / min to 0.55 mm / min.

7. A TC4 reinforced rare earth magnesium based composite material, characterized in that: The method is prepared by any one of claims 1 to 6.

8. The TC4 reinforced rare earth magnesium based composite material according to claim 7, characterized in that: The TC4 enhanced rare earth magnesium-based composite material has at least one of the following characteristics: Feature 1: TC4 particles are dispersed in the rare earth magnesium alloy; Feature 2: The mass proportion of Mg in the rare earth magnesium alloy is 85% to 90%, and the mass proportion of rare earth is 12% to 14%; the rare earth includes at least one of Gd and Y.

9. The TC4 reinforced rare earth magnesium based composite material according to claim 8, characterized in that: The rare earth magnesium alloy is an alloy containing Mg, Gd, Y, Zn and Zr.

10. An application of the TC4 reinforced rare earth magnesium based composite material as claimed in any one of claims 7 to 9, characterized in that: The TC4 reinforced rare earth magnesium-based composite material is used for preparing low-altitude flight components, aerospace components or new energy vehicle components.

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