Rare earth modified in-situ reinforced particle reinforced aluminum-based composite material and preparation method thereof

Abstract

The invention relates to the technical field of metal materials, and particularly provides a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material and a preparation method thereof.The preparation method of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material comprises the steps that reactants and rare earth oxide are mixed, pressed into blocks and dried, and reactant blocks are obtained; the reactant blocks are added into the aluminum alloy melt for a high-temperature self-propagating reaction, in-situ reinforced particles are generated, and particle reinforced aluminum matrix composite melt is obtained; and degassing the particle reinforced aluminum matrix composite melt, and preparing the rare earth modified in-situ reinforced particle reinforced aluminum matrix composite by adopting a near liquidus casting method. According to the preparation method, micron-sized reinforced phase particles are generated in situ under the conventional casting condition by utilizing the high-temperature self-propagating reaction of a reaction system and the activity effect of rare earth elements, and the aluminum-based composite material with the fine equiaxed crystal structure is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of metal materials, and in particular to a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material and a preparation method thereof. Background Art

[0002] Particle-reinforced aluminum-based composite materials combine the advantages of the matrix and reinforced particles to show excellent properties such as light weight, high strength, good plasticity and designability. They are widely used in aerospace, transportation, energy and environment and other fields. With the rapid development of high-tech industries, especially the rapid development of the transportation industry, higher requirements are put forward for improving the high power performance of the whole vehicle, reducing energy consumption and extending the driving range. In view of this, vehicle lightweighting has become an important way to promote the rapid development of the transportation industry. Particle-reinforced aluminum-based composite materials with stable performance and low cost have become the preferred material for lightweighting.

[0003] However, with the increasing demand for lightweighting in the transportation industry, higher requirements have been placed on the performance of particle-reinforced aluminum-based composites. Therefore, a simple and effective method is urgently needed to optimize the microstructure of particle-reinforced aluminum-based composites, so as to achieve the preparation of high-performance, lightweight components, further improve the power performance of the vehicle, reduce energy consumption and extend the driving range, and promote the rapid development of the transportation industry. Summary of the invention

[0004] The main purpose of the present invention is to provide a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material and a preparation method thereof. The present invention utilizes the high temperature self-propagating reaction of the reaction system and the active effect of the rare earth element to in-situ generate micron-sized reinforcement phase particles under conventional casting conditions to prepare an aluminum-based composite material with a fine equiaxed crystal structure. The preparation method provided by the present invention is simple and effective, and can further promote microstructure optimization under the condition of the microstructure of the traditional particle-reinforced phase-optimized alloy.

[0005] The first aspect of the present invention provides a method for preparing a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material, the preparation method comprising: mixing, briquetting and drying reactants and rare earth oxides according to the components required by the reaction system to obtain a reactant block; wherein the reactants are added in the form of a single substance or oxide powder, and the reactants include Al powder, TiO2 powder and C powder; the rare earth oxide is selected from Y2O3; heating an aluminum alloy to make it molten to obtain an aluminum alloy melt; adding the reactant block to the aluminum alloy melt for a high-temperature self-propagating reaction to generate in-situ reinforced particles to obtain a particle-reinforced aluminum-based composite material melt; degassing the particle-reinforced aluminum-based composite material melt, and adopting a near-liquidus casting method to obtain the rare earth modified in-situ reinforced particle-reinforced aluminum-based composite material.

[0006] In some embodiments of the present invention, the in-situ reinforcement particles include TiC particles and Al2O3 particles.

[0007] In some embodiments of the present invention, based on the mass of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material, the mass percentage of the in-situ reinforced particles is 0.5% to 6%.

[0008] In some embodiments of the present invention, the aluminum alloy has the following components by weight percentage: Mg 4.5%~5.5%, Zn 2.5%~3.5%, Si≤0.05%, Fe≤0.05%, Mn≤0.05%, and the balance is Al and unavoidable impurities.

[0009] In some embodiments of the present invention, the added mass of the rare earth oxide is 2% to 12% of the total mass of the reactants.

[0010] In some embodiments of the present invention, in the reaction system, the molar ratio of the reactant to the rare earth oxide is Al:TiO2:C:rare earth oxide=(2.8~5.0):(0.8~1.2):(1.1~1.3):(0.02~0.13).

[0011] In some embodiments of the present invention, the reactant and the rare earth oxide are uniformly mixed by ball milling, wherein the ball milling time is 40 min to 80 min.

[0012] In some embodiments of the present invention, the molding pressure of the reactant block is 14 MPa~16 MPa.

[0013] In some embodiments of the present invention, the drying temperature is 100° C. to 200° C., and the drying time is 20 min to 40 min.

[0014] In some embodiments of the present invention, the heating temperature of the aluminum alloy is 900°C to 1000°C.

[0015] In some embodiments of the present invention, the near-liquidus casting method uses a graphite mold with a temperature of 100°C to 200°C, and the casting temperature is 650°C to 700°C.

[0016] In some embodiments of the present invention, the degassing temperature of the particle reinforced aluminum-based composite material melt is 700°C to 850°C.

[0017] The second aspect of the present invention provides a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material, which is prepared by the preparation method of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material described in the first aspect.

[0018] Beneficial effects of the present invention: The present invention utilizes the high-temperature self-propagating reaction of the reaction system and the active effect of rare earth elements to generate micron-level reinforcement phase particles in situ under conventional casting conditions to prepare an aluminum-based composite material with fine equiaxed crystal structure.

[0019] The present invention can effectively promote the full reaction of the high-temperature self-propagating reaction of the system by adding rare earth elements into the reaction system. At the same time, the rare earth elements can also react with impurities to purify the alloy matrix, and can effectively optimize its structure.

[0020] The present invention utilizes a high-temperature self-propagating reaction of a reaction system to in-situ generate reinforcement phase particles in an alloy matrix, and the particle interface is pollution-free, thereby effectively optimizing the composite material structure.

[0021] The present invention can further optimize the composite material structure through near-liquidus casting.

[0022] The present invention optimizes the material structure step by step through three methods: rare earth elements, in-situ enhanced particles and near-liquidus casting.

[0023] The preparation environment of the present invention is in an atmospheric environment and at room temperature, and the adopted equipment and process flow are simple, without other special requirements, and can meet the conditions for large-scale production.

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. In the accompanying drawings: Figure 1 The microstructure of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material prepared in Example 1 of the present invention; Figure 2 The microstructure of the in-situ reinforced particles generated in Example 1 of the present invention; Figure 3 The microstructure of the rare earth modified in-situ reinforced particle reinforced aluminum matrix composite material prepared in Example 2 of the present invention; Figure 4 The microstructure of the rare earth modified in-situ reinforced particle reinforced aluminum matrix composite material prepared in Example 3 of the present invention; Figure 5The microstructure of the Al-5Mg-3Zn material prepared in Comparative Example 1 of the present invention; Figure 6 This is the microstructure of the in-situ particle reinforced composite material prepared in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention; the terms "including" and "having" in the specification and claims of the present invention and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0028] In the description of the embodiments of the present invention, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present invention, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In the description of the embodiments of the present invention, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In the description of the embodiments of the present invention, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0032] The present invention provides a method for preparing a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material. The key to the preparation method is to prepare the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material by rare earth doping, high temperature self-propagating reaction and near liquidus casting. The preparation method is simple and easy to implement, and conventional laboratory or factory conditions can be met without complex and expensive equipment. The rare earth modified in-situ reinforced particle reinforced aluminum-based composite material prepared by the preparation method of the present invention has a fine equiaxed crystal structure, which can meet the high comprehensive performance requirements in the field of composite materials.

[0033] The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material of the present invention is specifically carried out according to the following steps.

[0034] Prepare raw materials In an embodiment of the present invention, reactants, rare earth oxides and aluminum alloy (matrix aluminum alloy) are prepared according to the components required by the reaction system, wherein the reactants are added in the form of single substance or oxide powder.

[0035] In some embodiments of the present invention, the reactants include aluminum (Al) powder, TiO2 powder, and carbon (C) powder.

[0036] In some embodiments of the present invention, the rare earth oxide is selected from Y2O3.

[0037] In some embodiments of the present invention, the particle sizes of Al powder, TiO2 powder, C powder and Y2O3 are each independently smaller than 300 mesh.

[0038] In an embodiment of the present invention, the weight is calculated according to the total content of the in-situ reinforced particles in the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material and the corresponding molar ratio of the reactants, and the matrix aluminum alloy, reactant powder and rare earth oxide powder are weighed as needed.

[0039] In some embodiments of the present invention, the total content of the in-situ enhanced particles in the aluminum-based composite material enhanced by the rare earth modified in-situ enhanced particles can be adjusted according to demand, for example, based on the mass of the aluminum-based composite material enhanced by the rare earth modified in-situ enhanced particles, the mass percentage of the in-situ enhanced particles is 0.5% to 6%. Exemplarily, the mass percentage of the in-situ enhanced particles can be 0.6 wt.%, 1.0 wt.%, 1.5 wt.%, 2.0 wt.%, 2.5 wt.%, 3.0 wt.%, 3.5 wt.%, 4.0 wt.%, 4.5 wt.%, 5.0 wt.%, 5.5 wt.%, 6.0 wt.%, or any value that satisfies the above range.

[0040] In some embodiments of the present invention, the molar ratio of reactants to rare earth oxides in the reaction system can be adjusted according to demand, for example, the molar ratio of Al, TiO2, C and rare earth oxide is Al:TiO2:C:rare earth oxide=(2.8~5.0):(0.8~1.2):(1.1~1.3):(0.02~0.13). Preferably, Al:TiO2:C:rare earth oxide=(2.8~3.15):(1.0~1.2):(1.1~1.3):(0.04~0.10). Exemplarily, the molar ratio of Al, TiO2, C and rare earth oxide in the reaction system can be one of 3.15:1:1.2:0.042, 2.94:1:1.2:0.067, 2.80:1:1.2:0.084 or any value satisfying the above range.

[0041] In an embodiment of the present invention, the added mass of rare earth oxide is 2% to 12% of the total mass of the reactants. For example, the mass percentage of the mass of rare earth oxide to the total mass of the reactants can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12% or any value satisfying the above range.

[0042] In an embodiment of the present invention, the aluminum alloy comprises, by weight percentage, Mg 4.5% to 5.5%, Zn 2.5% to 3.5%, Si≤0.05%, Fe≤0.05%, Mn≤0.05%, and the remainder is Al and unavoidable impurities. In the aluminum alloy provided by the present invention, by weight percentage, the Zn content may be one of 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, or any value satisfying the above range value. The Mg content may be one of 4.5%, 4.6%, 4.7%, 4.8%, 4.9%, 5.0%, 5.1%, 5.2%, 5.3%, 5.4%, 5.5%, or any value satisfying the above range value.

[0043] Prepare reactant blocks In an embodiment of the present invention, reactants and rare earth oxides are mixed, briquette-pressed and dried to obtain reactant briquette.

[0044] In some embodiments of the present invention, the reactant powder and the rare earth oxide powder are evenly mixed by ball milling to ensure that the powders of each component are fully in contact with each other, and a reaction system powder for subsequently generating in-situ enhanced particles is obtained. In the embodiments of the present invention, the ball milling time can be adjusted as needed, for example, the ball milling time is 40 min to 80 min to achieve uniform mixing. Exemplarily, the ball milling time can be one of 40 min, 50 min, 60 min, 70 min, 80 min, or any value that meets the above range.

[0045] In some embodiments of the present invention, under pressure, the mixed powder of the reactant powder and the rare earth oxide is pressed into a block, and then the pressed block can be wrapped with aluminum foil and placed in a drying dish for standby use. The molding pressure of the reactant block in the embodiment of the present invention is 14 MPa to 16 MPa. Exemplarily, the molding pressure can be one of 14 MPa, 14.5 MPa, 15 MPa, 15.5 MPa, 16 MPa, or any value that meets the above range.

[0046] In some embodiments of the present invention, the pressed block is placed in a box-type resistance furnace at a preset temperature for a period of time to dry and remove moisture to obtain a reactant block. In the embodiment of the present invention, the drying temperature is 100°C to 200°C, and the drying time is 20 min to 40 min. Exemplarily, the drying temperature can be one of 100°C, 120°C, 140°C, 160°C, 180°C, 200°C, or any value that satisfies the above range. The drying time can be one of 20 min, 25 min, 30 min, 35 min, 40 min, or any value that satisfies the above range.

[0047] In some embodiments of the present invention, the size of the round pressed block or reactant block may be φ20-φ30. For example, the size of the reactant block may be one of φ20, φ22, φ24, φ26, φ28, φ30 or any value satisfying the above range.

[0048] Preparation of aluminum alloy melt In an embodiment of the present invention, the aluminum alloy is heated in a conventional environment to be in a molten state to obtain an aluminum alloy melt.

[0049] In some embodiments of the present invention, a crucible resistance furnace is used to heat it to a preset temperature, and then the matrix aluminum alloy is weighed and put into a graphite crucible and the graphite crucible is placed in a crucible resistance furnace that has reached the preset temperature to melt the aluminum alloy matrix into a molten state.

[0050] In some embodiments of the present invention, the preset temperature of the crucible resistance furnace, that is, the heating temperature of the aluminum alloy is 900° C. to 1000° C. For example, the heating temperature of the aluminum alloy can be one of 900° C., 950° C., 1000° C., or any value satisfying the above range.

[0051] In-situ generation of particle-reinforced aluminum matrix composite melts In an embodiment of the present invention, a reactant block is added into an aluminum alloy melt to carry out a high-temperature self-propagating reaction to generate in-situ reinforced particles, thereby obtaining a particle-reinforced aluminum-based composite material melt.

[0052] In some embodiments of the present invention, a dry reactant block is placed into an aluminum alloy melt using crucible tongs, and is thoroughly pressed into the molten aluminum alloy melt using a graphite bell jar. The melt temperature ignites a high-temperature self-propagating reaction of the reaction system, and the released heat continues to ignite the remaining reactants until the reaction is completed, thereby generating an in-situ particle-reinforced aluminum-based composite material melt, that is, in-situ reinforced particles are generated inside the aluminum alloy melt.

[0053] In an embodiment of the present invention, the in-situ reinforcement particles include TiC particles and Al2O3 particles.

[0054] In an embodiment of the present invention, under normal conditions, in-situ reinforced particles are generated by a high-temperature self-propagating reaction of reactants. During this process, the high-temperature self-propagating reaction of the reactants occurs in the matrix alloy melt, and the reinforcing phase is directly generated in the alloy. The interface between the particles and the matrix is ​​pollution-free and has a strong bonding ability. Moreover, rare earth elements are added to the reactant powder and directly participate in the reaction during the high-temperature self-propagating reaction, which can further effectively optimize the structure.

[0055] Degassing and slag removal In an embodiment of the present invention, the particle reinforced aluminum-based composite material melt is degassed.

[0056] In some embodiments of the present invention, when the temperature of the particle-reinforced aluminum-based composite material melt is reduced to the degassing temperature, the pre-prepared hexachloroethane is used for refining and degassing and the scum suspended on the surface of the melt is removed.

[0057] In some embodiments of the present invention, the degassing temperature of the particle-reinforced aluminum-based composite material melt is 700° C. to 850° C. For example, the degassing temperature may be one of 700° C., 750° C., 800° C., 850° C., or any value satisfying the above range.

[0058] Near-liquidus casting In an embodiment of the present invention, when the melt temperature of the particle-reinforced aluminum-based composite material drops to the liquidus temperature of the aluminum alloy, the rare earth-modified in-situ reinforced particle-reinforced aluminum-based composite material is cast.

[0059] In some embodiments of the present invention, when the temperature of the particle-reinforced aluminum-based composite material melt drops to near the liquidus temperature of the aluminum alloy, the particle-reinforced aluminum-based composite material melt in the crucible is poured into a preheated mold, and after air cooling, a rare earth-modified in-situ reinforced particle-reinforced aluminum-based composite material is obtained.

[0060] In some embodiments of the present invention, the casting temperature can also be understood as the liquidus temperature of the aluminum alloy being 650° C. to 700° C. For example, the casting temperature can be one of 650° C., 660° C., 670° C., 680° C., 700° C., or any value satisfying the above range.

[0061] In some embodiments of the present invention, the temperature of the mold is 100° C. to 200° C. For example, the temperature of the mold can be one of 100° C., 120° C., 140° C., 160° C., 180° C., 200° C., or any value within the above range.

[0062] In an embodiment of the present invention, a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material is prepared under conventional conditions by combining non-vacuum melting and near-liquidus casting.

[0063] In an embodiment of the present invention, rare earth elements are added to the reaction system, a rare earth modified in-situ reinforced phase particle reinforced aluminum-based composite material melt is prepared by utilizing a high-temperature self-propagating reaction, and further a rare earth modified in-situ reinforced particle in-situ reinforced aluminum-based composite material is prepared by near-liquidus casting to obtain a fine equiaxed crystal structure composite material.

[0064] In order to further improve the organization optimization of different types of aluminum-based composite materials under actual preparation conditions, the embodiments of the present invention allow the organization of the prepared aluminum-based composite materials to be optimized to a certain extent by screening the types of rare earth oxides and the molar ratio of reaction products.

[0065] The invention provides a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material, which is prepared by adopting the preparation method of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material and has a fine equiaxed crystal structure.

[0066] In the embodiments of the present invention, the advantages of grain refinement and organizational optimization are achieved by adding rare earth and in-situ reinforced particles, and an aluminum-based composite material reinforced with rare earth-modified in-situ reinforced particles having a fine equiaxed grain structure can be obtained.

[0067] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the amounts of the experimental reagents, unless otherwise specified, are the amounts of reagents used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0068] Example 1 A rare earth modified in-situ reinforced particle reinforced aluminum-based composite material Al-5Mg-3Zn-Y, the preparation method of which is as follows: Step ①: Prepare Al, TiO2, C and Y2O3 powders and Al-5Mg-3Zn alloy.

[0069] Step ②: Calculate the weight of each raw material according to the molar ratio of Al:TiO2:C:Y2O3=3.15:1:1.2:0.042, and the content of the generated in-situ reinforced particles accounts for 5.44 wt.% of the mass of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material, and weigh each raw material.

[0070] Step ③: Mix Al, TiO2, C, and Y2O3 powders, and mix Al, TiO2, C, and Y2O3 powders evenly by ball milling. The ball milling time is 60 min.

[0071] Step ④: Under a pressure of 15 MPa, the mixed powder obtained in step ③ was pressed into a block, and the pressed block was wrapped with aluminum foil and placed in a drying dish for later use.

[0072] Step ⑤: Heat the crucible resistance furnace to 980° C., put the weighed Al-5Mg-3Zn alloy matrix into a graphite crucible and place it in a crucible resistance furnace at 980° C., so that the aluminum alloy matrix is ​​in a molten state.

[0073] Step ⑥: Place the pressed block obtained in step ④ in a box-type resistance furnace at 120° C. to dry and remove moisture for 30 min.

[0074] Step ⑦: Use crucible tongs to place the dried reactant block in step ⑥ into an aluminum alloy melt at 980°C, and use a graphite bell jar to thoroughly press it into the molten aluminum alloy. The melt temperature ignites the high-temperature self-propagating reaction of the reaction system, and the heat released continues to ignite the remaining reactants until the reaction is completed, generating in situ a particle-reinforced aluminum-based composite melt, that is, TiC and Al2O3 reinforcing phase particles are generated in situ in the aluminum-based composite melt.

[0075] Step ⑧: When the temperature of the particle-reinforced aluminum-based composite material melt drops to 750° C., the pre-prepared hexachloroethane is used for refining and degassing, and the slag suspended on the surface of the melt is removed.

[0076] Step ⑨: When the temperature of the particle-reinforced aluminum-based composite material melt drops to the aluminum alloy liquidus temperature of 650°C, the particle-reinforced aluminum-based composite material melt in the crucible is poured into a mold, and after air cooling, a rare earth-modified in-situ reinforced particle-reinforced aluminum-based composite material is obtained.

[0077] Figure 1 The microscopic morphology of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material prepared in Example 1 is shown. It can be seen that the aluminum-based composite material has a fine equiaxed crystal structure with an average grain size of 45 μm.

[0078] Figure 2 The morphology of the in-situ reinforced particles prepared in Example 1 is shown. It can be seen that the in-situ reinforced particles are dispersed and the generated TiC and Al2O3 particles are submicron-sized and nearly spherical.

[0079] Example 2 The preparation process is exactly the same as that of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material in Example 1, the only difference being the molar ratio of the reactants.

[0080] The molar ratio of reactants in Example 2 is: Al:TiO2:C:Y2O3=2.94:1:1.2:0.067.

[0081] Figure 3 The microstructure of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material prepared in Example 2 is shown. It can be seen that the aluminum-based composite material also has a fine equiaxed crystal structure with an average grain size of 51 μm, which is slightly larger than the grain size of the aluminum-based composite material prepared in Example 1.

[0082] Example 3 The preparation process is exactly the same as that of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material in Example 1, the only difference being the molar ratio of the reactants.

[0083] The molar ratio of reactants in Example 3 is Al:TiO2:C:Y2O3=2.8:1:1.2:0.084.

[0084] Figure 4 The microstructure of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material prepared in Example 3 is shown. It can be seen that the aluminum-based composite material also has a fine equiaxed crystal structure with an average grain size of 68 μm, which is slightly larger than the grain size of the aluminum-based composite material prepared in Example 1.

[0085] Example 4 The preparation process is exactly the same as that of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material in Example 1, the only difference being the molar ratio of the reactants.

[0086] The molar ratio of reactants in Example 4 is Al:TiO2:C:Y2O3=3.5:1:1.2:0.0785.

[0087] Example 5 The preparation process is exactly the same as that of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material in Example 1, the only difference being the molar ratio of the reactants.

[0088] The molar ratio of reactants in Example 5 is Al:TiO2:C:Y2O3=3.5:1:1.2:0.1285.

[0089] Comparative Example 1 The preparation process of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material is exactly the same as that in Example 1, and the same Al-5Mg-3Zn matrix alloy is used. The difference is that in Comparative Example 1, no reactant powder and rare earth oxide are added.

[0090] Figure 5 The microstructure of the Al-5Mg-3Zn material prepared in Comparative Example 1 is shown. It can be seen that the base alloy prepared in Comparative Example 1 has coarse grains, with an average grain size of 211 μm.

[0091] Comparative Example 2 The preparation process of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material is exactly the same as that in Example 1, except that no rare earth element is added in Comparative Example 2.

[0092] Figure 6 The microstructure of the composite material prepared in Comparative Example 2 is shown. It can be seen that the base alloy grains prepared in Comparative Example 2 are equiaxed, with an average grain size of 71 μm. Compared with the base material prepared in Comparative Example 1, the in-situ enhanced particles formed have a significant effect on optimizing the organization.

[0093] In summary, the present invention can realize the preparation and organization regulation of aluminum-based composite materials reinforced by rare earth-modified in-situ reinforced particles, and the addition of rare earth and in-situ reinforced particles has a significant effect on the optimization of the microstructure of the composite material.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for preparing a rare earth modified in-situ reinforced particle reinforced aluminum-based composite material, characterized in that: The preparation method comprises: According to the components required by the reaction system, reactants and rare earth oxides are mixed, briquette and dried to obtain reactant blocks; wherein the reactants are added in the form of simple substances or oxide powders, and the reactants include Al powder, TiO2 powder and C powder; and the rare earth oxide is selected from Y2O3; The aluminum alloy is heated to be in a molten state to obtain an aluminum alloy melt; Adding the reactant block into the aluminum alloy melt to carry out a high-temperature self-propagating reaction to generate in-situ reinforced particles, thereby obtaining a particle-reinforced aluminum-based composite material melt; The particle-reinforced aluminum-based composite material melt is degassed, and the rare earth-modified in-situ reinforced particle-reinforced aluminum-based composite material is prepared by a near-liquidus casting method.

2. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: The in-situ reinforcement particles include TiC particles and Al2O3 particles.

3. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: Based on the mass of the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material, the mass percentage of the in-situ reinforced particles is 0.5% to 6%.

4. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: The aluminum alloy comprises, by weight percentage, Mg 4.5%-5.5%, Zn 2.5%-3.5%, Si≤0.05%, Fe≤0.05%, Mn≤0.05%, and the remainder is Al and unavoidable impurities.

5. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: The added mass of the rare earth oxide is 2% to 12% of the total mass of the reactants.

6. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: In the reaction system, the molar ratio of the reactant to the rare earth oxide is Al:TiO2:C:rare earth oxide=(2.8~5.0):(0.8~1.2):(1.1~1.3):(0.02~0.13).

7. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: The reactant and the rare earth oxide are uniformly mixed by ball milling, wherein the ball milling time is 40 min to 80 min; The molding pressure of the reactant block is 14 MPa to 16 MPa; The drying temperature is 100° C. to 200° C., and the drying time is 20 min to 40 min.

8. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: The heating temperature of the aluminum alloy is 900°C to 1000°C.

9. The method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to claim 1, characterized in that: The near-liquidus casting method uses a graphite mold with a temperature of 100°C to 200°C and a casting temperature of 650°C to 700°C; The degassing temperature of the particle-reinforced aluminum-based composite material melt is 700°C to 850°C.

10. A rare earth modified in-situ reinforced particle reinforced aluminum matrix composite material, characterized in that: The composite material is prepared by the method for preparing the rare earth modified in-situ reinforced particle reinforced aluminum-based composite material according to any one of claims 1 to 9.

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