Preparation method of novel high-strength metal-based composite material

Abstract

The invention discloses a preparation method of a novel high-strength metal-based composite material, and relates to the technical field of composite materials. The preparation method comprises the following steps: preparing high-entropy alloy particles; the high-entropy alloy particles are evenly laid at the bottom of a casting ladle, then metal matrix melt is poured into the casting ladle, the casting ladle is stirred and cooled after the metal matrix melt is poured, and semi-solid slurry is prepared till the solid fraction of metal in the casting ladle reaches 0.4-0.5; casting a required composite blank by adopting a semi-solid casting process; and the cast composite blank is subjected to heat treatment, and the needed high-entropy alloy particle reinforced metal matrix composite is obtained through grinding and cutting. By adopting the high-entropy alloy particle reinforced composite material and utilizing the natural interface bonding characteristic between the high-entropy alloy and the metal matrix, the thermal expansion coefficient difference is small, and the defects that the interface bonding stability is poor and the plasticity and toughness are insufficient in the traditional composite material production process are overcome.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a method for preparing a new high-strength metal-based composite material. Background Art

[0002] Compared with traditional metal materials, metal matrix composites have many excellent properties that single-phase materials do not have. They have been widely used in aerospace, transportation, manufacturing and other fields, and have gradually become important materials in many high-tech fields.

[0003] Particle-reinforced metal matrix composites have the advantages of high specific stiffness, high specific strength, wear resistance, and dimensional stability, and have been widely used in aerospace, transportation, and manufacturing industries. Traditional ceramic particle-reinforced metal matrix composites have problems such as poor wettability between ceramic particles and metal matrix interfaces, mismatched thermal expansion coefficients, etc., which make it difficult for the reinforcing phase in the composite material to diffuse, cannot be completely miscible with the matrix material, and the interface bonding between ceramic particles and metal matrix is ​​poor, resulting in insufficient plasticity and toughness of the composite material! Moreover, when the volume fraction of ceramic particles reaches a critical value, it is difficult to evenly disperse fine ceramic particles in the metal matrix by conventional methods. When metallic glass (such as Zr-based, Al-based, Mg-based, etc.) particles are used to reinforce metal matrix composites, although there is good interface bonding, the amorphous phase of metallic glass is easy to form products at high temperatures due to factors such as low crystallization temperature, which leads to the destruction of the interface stability between the reinforcing phase and the matrix, making the composite material prone to fracture, and it is difficult to obtain a high sintering quality during low-temperature sintering. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a high-strength metal-based composite new material, which adopts a high-entropy alloy particle reinforced composite material, utilizes the natural interface bonding characteristics between metals between the high-entropy alloy and the metal matrix, and overcomes the shortcomings of poor interface bonding stability and insufficient plasticity and toughness in the production of traditional composite materials, and solves the problems raised by the background technology.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] The present invention is a method for preparing a high-strength metal-based composite new material, comprising:

[0007] Step 1, preparing high entropy alloy particles, wherein the high entropy alloy is an alloy material formed by 5 or more metal elements in equal or approximately equal amounts;

[0008] Step 2, evenly laying high entropy alloy particles on the bottom of the ladle, then pouring the metal matrix molten liquid into the ladle, stirring and cooling the ladle after the metal matrix molten liquid is poured in, and preparing a semi-solid slurry until the solid phase ratio of the metal in the ladle reaches 0.4-0.5;

[0009] Step 3: using a semi-solid casting process to cast the required composite blank;

[0010] Step 4: heat-treating the cast composite blank, and grinding and cutting to obtain the desired high-entropy alloy particle-reinforced metal matrix composite material.

[0011] Furthermore, the high entropy alloy is an alloy material formed by 5-13 metal elements in equal or approximately equal amounts.

[0012] Furthermore, the high entropy alloy particles include AlxCoCrFeN i, AlxCoCrCuFeN i, AIxCoCrFeN i T i, T ix CoCrCuFeN i, AlxTVCrMnFeCoN i Cu, Cu-N iAI CoCrFeT i Mo, AI CoCrCuFeN i S i.

[0013] Furthermore, the preparation of high entropy alloy particles in step 1 specifically includes:

[0014] Stp1, pre-treating the raw materials for preparing the high entropy alloy;

[0015] Stp2, weighing the pretreated raw materials according to the proportions of the components of the high entropy alloy;

[0016] Stp3, mixing the single substance powders of the processed raw materials to obtain high entropy alloy powder;

[0017] Step 4, putting the obtained high entropy alloy powder into smelting equipment A for smelting and cooling to obtain alloy ingots;

[0018] Step 5, processing the obtained alloy ingot, and then sending it to the smelting equipment B, and casting it to obtain the high entropy alloy block after the alloy is completely melted;

[0019] Step 6, processing the high entropy alloy block to obtain high entropy alloy particles in the form of ellipsoidal particles or flaky particles.

[0020] Furthermore, the average particle size of the ellipsoidal particles is 53 μm; the average particle size of the flaky particles is 15 μm.

[0021] Furthermore, in Stp1, the raw material of the high entropy alloy is polished, cleaned and dried to remove impurities.

[0022] Furthermore, Stp7 is included after Stp6, and Stp7 specifically includes hot forging at a temperature of 900° C. or above to refine the grains of the high entropy alloy.

[0023] Furthermore, the metal matrix includes cast iron or cast steel, Al-based composite materials and Cu-based composite materials.

[0024] The present invention has the following beneficial effects:

[0025] The present invention adopts high entropy alloy particle reinforced composite material, and utilizes the natural interface bonding characteristics between metals between high entropy alloy and metal matrix to overcome the shortcomings of poor interface bonding stability and insufficient plastic toughness in the production of traditional composite materials.

[0026] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0028] Figure 1 The present invention is a flow chart of the method for preparing the new composite material. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0031] like Figure 1 As shown, the present invention is a method for preparing a new high-strength metal-based composite material, comprising:

[0032] Step 1: Preparation of high entropy alloy particles Alx CoCrFeN i;

[0033] Step 2, evenly laying AlCoCrFeNi particles at the bottom of the ladle, and then pouring the Cu-based composite material melt into the ladle; controlling the volume fraction of AlCoCrFeNi particles in the particle-reinforced metal-based composite material to be 35%, stirring and cooling the ladle after the Cu-based composite material melt is poured in, and preparing a semi-solid slurry until the solid phase ratio of the metal in the ladle reaches 0.5;

[0034] Step 3: using a semi-solid casting process to cast the required composite blank;

[0035] Step 4: heat-treating the cast composite blank, and grinding and cutting to obtain the desired high-entropy alloy particle-reinforced metal matrix composite material.

[0036] It can be known that in the present invention, compared with ceramic particles, a stable metallurgical bond is produced at the interface between the high entropy alloy particles and the metal matrix, and a diffusion layer is formed, so that the interface wettability and compatibility of the high entropy alloy particle-reinforced metal-based composite material are better than those of ceramic particles; at the same time, compared with metallic glass particles, the high entropy alloy particles have good thermal stability, so that the strengthening phase composition and properties remain stable during the processing process, and the composition and properties of the composite material will not change due to temperature changes.

[0037] In the above, no grain growth and intermetallic phase occurred in the AlCoCrFeNi high entropy alloy in the Cu-based composite during the sintering process, and the AlCoCrFeNi high alloy had a better strengthening effect than the metallic glass.

[0038] In other embodiments, Al x CoCrCuFeNi、AI x CoCrFeN iTi、Ti x CoCrCuFeNi、Al x TVCrMnFeCoNiCu, Cu-NiAICoCrFeTiMo, AICoCrCuFeNiSi, etc. replace Al in the above x CoCrFeNi.

[0039] In other embodiments, one of steel-based, magnesium-based, aluminum-based, magnesium-based, nickel-based and titanium-based composite materials may be used to replace the Cu-based composite material mentioned above.

[0040] The preparation of high entropy alloy particles specifically includes:

[0041] Stp1, grinding, cleaning and drying the raw materials for preparing high entropy alloy to remove impurities;

[0042] Stp2, weighing the pretreated raw materials according to the proportions of the components of the high entropy alloy;

[0043] Stp3, mixing the single substance powders of the processed raw materials to obtain high entropy alloy powder;

[0044] Step 4, putting the obtained high entropy alloy powder into smelting equipment A for smelting and cooling to obtain alloy ingots;

[0045] Step 5, processing the obtained alloy ingot, and then sending it to the smelting equipment B, and casting it to obtain the high entropy alloy block after the alloy is completely melted;

[0046] Step 6, processing the high entropy alloy block to obtain high entropy alloy particles in the form of ellipsoidal particles or flaky particles;

[0047] Stp7. Hot forging at 900℃ or above can refine the grains of high entropy alloy and further improve the mechanical properties of the material.

[0048] In step 3, the mixed powder is gradually alloyed during high-energy ball milling to finally form an alloy powder with a single / double-phase BCC structure.

[0049] Specifically, the high entropy alloy preparation method provided by the present invention can realize the preparation of the above-mentioned high entropy alloy, by pretreating the raw materials, treating the smelting environment and making the elements evenly distributed during the smelting process. Thus, by using the above method, a high entropy alloy with high purity and uniform distribution of elements can be prepared.

[0050] At the same time, the raw materials can be polished, cleaned and dried to remove impurities, thereby improving the purity of the raw materials. For example, the raw materials of the high entropy alloy can be polished with sandpaper to remove the oxide layer on the surface; after that, the raw materials are placed in an organic solution and cleaned with ultrasound, for example, in alcohol and acetone, and after cleaning, the raw materials are dried. The cleaning and drying operations can remove the residual substances produced by grinding on the surface of the raw materials.

[0051] In the above, in order to verify the different effects of ellipsoidal particles and flaky particles when used; in the process of preparing high-strength metal-based composite new materials, ellipsoidal particles and flaky particles can be used, and the average particle size of ellipsoidal particles is 53μm, and the average particle size of flaky particles is 15μm. Ellipsoidal high entropy alloy powders are easier to mix evenly with aluminum powders, while flaky high entropy alloy powders are prone to agglomeration; and the fracture of ellipsoidal particle-reinforced composite materials is mainly due to the tearing of the matrix: while the fracture of flaky particle-reinforced composite materials is mainly due to the rupture of agglomerated particles.

[0052] Compared with composite materials prepared by general powder metallurgy process and casting process, the metal-based ceramic particle reinforced composite material prepared by the process of the present invention can reduce the thinning degree by 20-40% in the wear resistance thinning test under the same conditions, and the wear resistance is greatly improved; through microscopic observation of metallographic structure, the number of composite interface cracks counted per unit size is significantly reduced.

[0053] From a microscopic perspective, the interface between the high-entropy alloy reinforcement and the matrix can effectively transfer the load borne on the matrix to the reinforcement particles, and the blocking effect of the interface can effectively prevent crack propagation and delay the occurrence of stress concentration, thereby improving the strength of the composite material.

[0054] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0055] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a new high-strength metal-based composite material, characterized in that: include: Step 1, preparing high entropy alloy particles, wherein the high entropy alloy is an alloy material formed by 5 or more metal elements in equal or approximately equal amounts; Step 2, evenly laying high entropy alloy particles on the bottom of the ladle, then pouring the metal matrix molten liquid into the ladle, stirring and cooling the ladle after the metal matrix molten liquid is poured in, and preparing a semi-solid slurry until the solid phase ratio of the metal in the ladle reaches 0.4-0.5; Step 3: using a semi-solid casting process to cast the required composite blank; Step 4: heat-treating the cast composite blank, and grinding and cutting to obtain the desired high-entropy alloy particle-reinforced metal matrix composite material.

2. The method for preparing a high-strength metal-based composite new material according to claim 1, characterized in that: The high entropy alloy is an alloy material formed by 5 to 13 metal elements in equal or approximately equal amounts.

3. A method for preparing a high-strength metal-based composite new material according to claim 1 or 2, characterized in that: The high entropy alloy particles include Al x CoCrFeNi、Al x CoCrCuFeNi、AI x CoCrFeNiTi, TixCoCrCuFeNi, Al x TVCrMnFeCoNiCu, Cu-NiAICoCrFeTiMo, AICoCrCuFeNiSi.

4. The method for preparing a high-strength metal-based composite new material according to claim 1, characterized in that: The preparation of high entropy alloy particles in step 1 specifically includes: Stp1, pre-treating the raw materials for preparing the high entropy alloy; Stp2, weighing the pretreated raw materials according to the proportions of the components of the high entropy alloy; Stp3, mixing the single substance powders of the processed raw materials to obtain high entropy alloy powder; Step 4, putting the obtained high entropy alloy powder into smelting equipment A for smelting and cooling to obtain alloy ingots; Step 5, processing the obtained alloy ingot, and then sending it to the smelting equipment B, and casting it to obtain the high entropy alloy block after the alloy is completely melted; Step 6, processing the high entropy alloy block to obtain high entropy alloy particles in the form of ellipsoidal particles or flaky particles.

5. The method for preparing a high-strength metal-based composite new material according to claim 4, characterized in that: The average particle size of the ellipsoidal particles is 53 μm; the average particle size of the flaky particles is 15 μm.

6. The method for preparing a high-strength metal-based composite new material according to claim 4, characterized in that: In Stp1, the raw material of the high entropy alloy is polished, cleaned and dried to remove impurities.

7. The method for preparing a high-strength metal-based composite new material according to claim 4, characterized in that: Stp7 is included after Stp6, and Stp7 specifically includes hot forging at a temperature of 900° C. or above to refine the grains of the high entropy alloy.

8. The method for preparing a high-strength metal-based composite new material according to claim 1, characterized in that: The metal matrix includes cast iron or cast steel, Al-based composite materials and Cu-based composite materials.

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