Composite ball with gradient interface as well as preparation method and application of composite ball

Abstract

The invention discloses a composite ball with a gradient interface and a preparation method and application of the composite ball, and belongs to the technical field of metal-based composite materials. The preparation method comprises the following steps: (1) mixing mixed powder with high ceramic content with a binder, and carrying out shot blasting to prepare an inner core composite ball; (2) mixing the inner core composite ball with the mixed powder with the middle ceramic content and a binder, and performing shot blasting, so that the inner core composite ball is wrapped by the mixed powder with the middle ceramic content, and an intermediate composite ball of which the particle size is increased is obtained; and (3) the middle composite ball and the mixed powder with the low ceramic content are mixed and subjected to shot blasting, the middle composite ball is wrapped with the mixed powder with the low ceramic content, and the composite ball with the gradient interface is obtained. And (4) drying the composite ball. The composite ball with the gradient interface is prepared and serves as a reinforcing phase to be compounded with the metal matrix, and therefore the ceramic particle reinforced metal matrix composite with the good combination effect of a composite area and excellent comprehensive performance is obtained.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite technology, and relates to a composite sphere with a gradient interface, its preparation method and application. Background Technology

[0002] Ceramic particle reinforced metal matrix composites (MMCs) aim to combine the superior properties of ceramic particle reinforcing phases with those of a metal matrix material. This allows for the achievement of high hardness, high strength, high wear resistance, and corrosion resistance in a single material, while retaining the good ductility, toughness, and processability of the metal. However, in existing technologies, while the strength and wear resistance of composites improve after ceramic particle reinforcement, a significant decrease in ductility and toughness is often accompanied by an improvement. This fails to achieve the ideal combination of superior properties in ceramic particle reinforced metal matrix composites, severely limiting their practical application. Therefore, maintaining the ductility and toughness of the composite material while improving its wear resistance and hardness is of great significance for enhancing its overall performance.

[0003] Furthermore, patent CN103878346A discloses a method for preparing a multi-scale ceramic particle reinforced metal matrix composite material. This method improves the wear resistance of the composite material while maintaining high impact and wear resistance by uniformly dispersing multi-scale spherical ceramic particle reinforcing phases within a metal matrix. However, in this composite material, the interface between the ceramic particles and the metal matrix still exhibits a "hard interface" with abrupt performance changes. The interface between the metal matrix and the ceramic particle reinforcing phase composite region is relatively weak, making it prone to crack formation and becoming the source of crack propagation. Once cracks form, they further propagate, leading to the destruction of the composite material and affecting its normal use.

[0004] Patent CN104874768B proposes a method for preparing ceramic particle-reinforced metal matrix composites with complex spatial structures based on 3D printing technology. This method first prepares a plastic template with a complex spatial structure using 3D printing technology, then injects ceramic slurry into the template to form a ceramic particle preform with a complex spatial structure. Finally, the metal matrix composite is prepared using pressure impregnation techniques such as vacuum casting and extrusion casting. However, the size of the ceramic particle preform is limited during the preparation process, and the manufacturing process is relatively complex.

[0005] Therefore, it is necessary to provide a composite sphere with a gradient interface, its preparation method and application, to improve the interfacial bonding effect between the matrix and the ceramic particle reinforcement phase composite region, and to effectively improve the hardness, strength, wear resistance and other properties of the composite material while maintaining its excellent plasticity and toughness. Summary of the Invention

[0006] To overcome the problems in the prior art, this invention prepares composite spheres with gradient interfaces using a simple preparation method, and uses them as reinforcing phases to composite with a metal matrix. This effectively improves the interfacial bonding effect between the matrix and the ceramic particle reinforcing phase composite region, reduces or eliminates crack propagation sources, and effectively improves the hardness, strength, wear resistance and other properties of the composite material while maintaining its excellent plasticity and toughness. This results in better overall performance and a longer service life for the composite material.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: This invention proposes a method for preparing composite spheres with gradient interfaces, the method comprising the following steps: (1) Mix the high ceramic content powder with the binder and shot blast to make core composite spheres.

[0008] (2) The core composite spheres obtained in step (1) are mixed with mixed powder of medium ceramic content and binder and shot blasted to coat the core composite spheres with mixed powder of medium ceramic content, thereby obtaining intermediate composite spheres with larger particle size.

[0009] (3) The intermediate composite sphere obtained in step (2) is mixed with a mixed powder with low ceramic content and a binder and shot blasted so that the mixed powder with low ceramic content coats the intermediate composite sphere, resulting in a composite sphere with a gradient interface.

[0010] (4) Dry the composite balls in step (3).

[0011] To ensure that the final composite spheres with gradient interfaces have a relatively uniform particle size, the core composite spheres can be sieved before preparing the intermediate composite spheres to obtain core composite spheres with a relatively uniform particle size. The core composite spheres with a relatively uniform particle size are then mixed with mixed powder with a medium ceramic content and shot blasted. After that, the intermediate composite spheres with a relatively uniform particle size are sieved out, mixed with mixed powder with a low ceramic content, and shot blasted.

[0012] Adhesives can be selected from conventional options such as polyvinyl alcohol and methylcellulose.

[0013] Preferably, in the high ceramic content mixed powder, the volume of ceramic powder accounts for 60% to 80% of the total volume of the mixed powder, and the remainder is metal powder.

[0014] In the mixed powder with medium ceramic content, the volume of ceramic powder ≤ 40% accounts for < 60% of the total volume of the mixed powder, and the remainder is metal powder.

[0015] In the mixed powder with low ceramic content, the volume of ceramic powder ≤ 20% accounts for < 40% of the total volume of the mixed powder, and the remainder is metal powder.

[0016] The ceramic powder can be made of materials such as tungsten carbide (WC), titanium carbide (TiC), boron carbide (B4C), titanium nitride (TiN), and titanium diboride (TiB2). The ceramic powder can be a single-component material or a mixture of multiple components in any proportion.

[0017] The types of metal powders that are combined with ceramic powders are the same as or have the same main elements as the metal matrix.

[0018] Preferably, in the composite sphere, the mass ratio of the mixed powder with high ceramic content, the mixed powder with medium ceramic content, and the mixed powder with low ceramic content is 1:1:2.

[0019] Preferably, in step (1), the binder is added at a mass of 1% to 5% of the mass of the ceramic powder in the mixed powder with high ceramic content.

[0020] In step (2), the binder is added at a mass of 1% to 5% of the mass of ceramic powder in the mixed powder with medium ceramic content.

[0021] In step (3), the binder is added at a mass of 1% to 5% of the ceramic powder mass in the mixed powder with low ceramic content.

[0022] Preferably, in steps (1), (2), and (3), the shot blasting speed is 40~80 r / min and the shot blasting temperature is 80~120℃.

[0023] Preferably, in the mixed powder with high ceramic content, mixed powder with medium ceramic content, and mixed powder with low ceramic content, the types of ceramic powder are the same as the types of metal powder.

[0024] In another aspect, the present invention proposes a composite sphere with a gradient interface, which is prepared by the above-described preparation method.

[0025] This invention also proposes the application of the above-mentioned composite spheres as a reinforcing phase to be combined with a metal matrix to obtain ceramic particle reinforced metal matrix composite materials.

[0026] The ceramic composite spheres and the metal matrix are composited using a conventional infiltration casting process. First, the ceramic composite spheres are mixed with a binder and added to a mold, and then sintered to form a preform. Then, the metal matrix is ​​melted and infiltrated into the preform.

[0027] The beneficial effects of this invention are: 1. This invention prepares composite spheres with gradient interfaces and uses these composite spheres as reinforcing phases to composite with a metal matrix, resulting in a ceramic particle-reinforced metal matrix composite material. The outer layer has a low ceramic content, exhibiting properties closest to the metal matrix, good bonding, and low interfacial stress. When the metal matrix composite material is subjected to stress, the stress is transferred to the composite spheres and buffered by a coating layer formed by the mixed ceramic powder in the middle layer, preventing sudden changes in performance. During stress transfer, the core composite sphere bears the main load, while the outer and middle layers absorb energy through plastic deformation, preventing cracks from propagating to the core or initiating at the interface. This not only maintains the composite material's good plasticity and toughness but also helps improve its toughness, thereby effectively enhancing the composite material's strength, hardness, wear resistance, and toughness. It truly combines the excellent properties of the ceramic particle reinforcing phase with the metal matrix material, giving the composite material superior comprehensive performance.

[0028] 2. This invention prepares composite spheres with gradient interfaces and uses the composite spheres as a reinforcing phase to combine with a metal matrix to obtain a ceramic particle-reinforced metal matrix composite material. This effectively improves the bonding effect between the metal matrix and the ceramic particle composite region, thereby reducing or eliminating crack propagation sources, lowering the probability of crack propagation in the composite material, improving the processing performance of the composite material, and extending the service life of the composite material.

[0029] 3. By adjusting the volume fraction of the mixed powder components in each layer of the composite sphere, this invention can effectively control the plasticity, toughness, strength, wear resistance, and other properties of the composite material, so that the ceramic particle reinforced metal matrix composite material can meet the needs of more diverse application scenarios.

[0030] 4. This invention uses composite spheres as a reinforcing phase to composite with a metal matrix. The size and structure of the ceramic-reinforced metal matrix composite material are not limited and can be adjusted according to actual application requirements.

[0031] 5. The preparation method of this invention is simple, easy to operate, and suitable for industrial application. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the preparation method of the composite sphere with gradient interface of the present invention; Figure 2 This is a schematic diagram of the ceramic particle reinforced metal matrix composite material structure of the present invention. In the figure, I is the core composite sphere, II is the coating layer formed by mixed powder with medium ceramic content, and III is the coating layer formed by mixed powder with low ceramic content. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0034] Example 1 In this embodiment, high-manganese steel of grade ZGMn13Cr2 was selected as the metal matrix, TiC with a particle size of approximately 10 μm was selected as the ceramic powder, and ZGMn13Cr2 high-manganese steel alloy powder with a particle size of approximately 10 μm was selected as the metal powder. The ceramic particle reinforced metal matrix composite material was prepared by the following method: (1) Preparation of mixed powders TiC ceramic powder and ZGMn13Cr2 high manganese steel alloy powder were mixed by ball milling at ceramic powder volume fractions of 60%, 40%, and 20% (corresponding to high, medium, and low ceramic contents, respectively), to obtain mixed powders with three ceramic contents.

[0035] (2) Preparation of gradient composite spheres ① Set the shot blasting machine speed to 45 r / min and the heating plate temperature to 80℃. Add the high ceramic content (60% TiC) mixed powder and 1% of the ceramic powder mass of binder (polyvinyl alcohol) into the shot blasting machine. The mixture rotates in the shot blasting machine to form a core composite ball. After sieving, a uniform core composite ball is obtained.

[0036] ② Weigh out the mixed powder with medium ceramic content according to the mass ratio of high ceramic content mixed powder to medium ceramic content mixed powder = 1:1. Put the mixed powder with medium ceramic content and 1% of the mass of ceramic powder binder into a shot blasting machine to roll and enlarge it to obtain an intermediate composite ball.

[0037] ③ Finally, weigh the low ceramic content mixed powder according to the mass ratio of low ceramic content mixed powder to medium ceramic content mixed powder = 2:1. Add the low ceramic content (20% TiC) mixed powder, intermediate composite spheres, and 1% of the mass of ceramic powder binder to the shot blasting machine. Repeat the rolling and sieving operations to form a gradient structure outer layer coating and obtain composite spheres with gradient interfaces.

[0038] ④ Dry the composite balls for later use.

[0039] (3) Preparation of composite materials By using a diffusion casting process, high manganese steel ZGMn13Cr2 is combined with composite spheres to obtain a ceramic particle reinforced metal matrix composite material, wherein the volume of ceramic particles and the volume of the metal matrix composite material each account for 50%.

[0040] In this embodiment, the ceramic particle-reinforced metal matrix composite material contains uniformly dispersed gradient spherical composite spheres with a diameter of 4 mm. Each composite sphere contains uniformly dispersed TiC particles with a particle size of 10 micrometers, forming a composite material with a gradient structure. The hardness of the composite region of the composite material is 55 HRC, which is about 2.7 times higher than that of the high manganese steel matrix, and the yield strength is 1000 MPa, which is about 1 time higher than that of the high manganese steel matrix.

[0041] Example 2 In this embodiment, 40Cr alloy steel is selected as the metal matrix, WC with a particle size of approximately 30 μm is selected as the ceramic powder, and 40Cr alloy steel powder with a particle size of approximately 10 μm is selected as the metal powder. The ceramic particle reinforced metal matrix composite material is prepared by the following method: (1) Preparation of mixed powders By ball milling, WC ceramic powder and 40Cr alloy steel powder were mixed at ceramic powder volume fractions of 70%, 48%, and 28% (corresponding to high, medium, and low ceramic contents, respectively) to obtain mixed powders with three ceramic contents.

[0042] (2) Preparation of gradient composite spheres ① Set the shot blasting machine speed to 40 r / min and the heating plate temperature to 100℃. Add the high ceramic content (70% WC) mixed powder and 3% of the ceramic powder mass of binder (polyvinyl alcohol) into the shot blasting machine. The mixture rotates in the shot blasting machine to form a core composite ball. After sieving, a uniform core composite ball is obtained.

[0043] ② Weigh out the mixed powder with medium ceramic content according to the mass ratio of high ceramic content mixed powder to medium ceramic content mixed powder = 1:1. Put the mixed powder with medium ceramic content and 3% of the mass of ceramic powder binder into a shot blasting machine to roll and enlarge it to obtain intermediate composite spheres.

[0044] ③ Finally, weigh the low ceramic content mixed powder according to the mass ratio of low ceramic content mixed powder to medium ceramic content mixed powder = 2:1. Add the low ceramic content (28% WC) mixed powder, intermediate composite spheres, and 3% of the mass of ceramic powder binder into the shot blasting machine. Repeat the rolling and sieving operations to form a gradient structure outer layer coating and obtain composite spheres with gradient interfaces.

[0045] ④ Dry the composite balls for later use.

[0046] (3) Preparation of composite materials By combining 40Cr alloy steel with composite spheres through infiltration casting, ceramic particle reinforced metal matrix composite material is obtained, wherein ceramic particles account for 40% of the volume of the metal matrix composite material.

[0047] In this embodiment, the ceramic particle-reinforced metal matrix composite material contains uniformly dispersed gradient spherical composite spheres with a diameter of 6 mm. Each sphere contains uniformly dispersed WC particles with a particle size of 30 μm, forming a composite material with a gradient structure. The composite region of the composite material has a hardness of 65 HRC and an impact toughness of 16 J / cm², which is approximately 40% higher than that of the matrix material.

[0048] Example 3 In this embodiment, high-manganese steel of grade ZGMn13Cr2 was selected as the metal matrix, B4C with a particle size of approximately 10 μm was selected as the ceramic powder, and ZGMn13Cr2 high-manganese steel alloy powder with a particle size of approximately 10 μm was selected as the metal powder. The ceramic particle reinforced metal matrix composite material was prepared by the following method: (1) Preparation of mixed powders By ball milling, B4C ceramic powder and ZGMn13Cr2 high manganese steel alloy powder were mixed at ceramic powder volume fractions of 80%, 55%, and 35% respectively (corresponding to high, medium, and low ceramic contents) to obtain mixed powders with three ceramic contents.

[0049] (2) Preparation of gradient composite spheres ① Set the shot blasting machine speed to 80 r / min and the heating plate temperature to 120℃. Add the high ceramic content (80% B4C) mixed powder and 5% of the ceramic powder mass of binder (polyvinyl alcohol) into the shot blasting machine. The mixture rotates in the shot blasting machine to form a core composite ball. After sieving, a uniform core composite ball is obtained.

[0050] ② Weigh out the mixed powder with medium ceramic content according to the mass ratio of high ceramic content mixed powder to medium ceramic content mixed powder = 1:1. Put the mixed powder with medium ceramic content and 5% of the mass of ceramic powder binder into a shot blasting machine to roll and enlarge it to obtain intermediate composite spheres.

[0051] ③ Finally, weigh the low ceramic content mixed powder according to the mass ratio of low ceramic content mixed powder to medium ceramic content mixed powder = 2:1. Add the low ceramic content (35% B4C) mixed powder, intermediate composite spheres, and 5% of the mass of ceramic powder binder into the shot blasting machine. Repeat the rolling and sieving operations to form a gradient structure outer layer coating, and obtain composite spheres with gradient interfaces.

[0052] ④ Dry the composite balls for later use.

[0053] (3) Preparation of composite materials By using a diffusion casting process, high manganese steel ZGMn13Cr2 is combined with composite spheres to obtain a ceramic particle reinforced metal matrix composite material, wherein the volume of ceramic particles and the volume of the metal matrix composite material each account for 50%.

[0054] The performance of the ceramic particle-reinforced metal matrix composite material in this embodiment is similar to that in Example 1.

[0055] In summary, this invention prepares composite spheres with gradient interfaces and uses these composite spheres as reinforcing phases to composite with a metal matrix, thereby obtaining a ceramic particle-reinforced metal matrix composite material with good bonding effect in the composite region and excellent overall performance.

[0056] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method of making a composite sphere having a gradient interface, the method comprising: The preparation method comprises the following steps: ​ (1) mixing high ceramic content mixed powder with a binder and performing shot blasting to prepare a core composite ball; (2) mixing the core composite ball obtained in step (1) with medium ceramic content mixed powder and a binder and performing shot blasting to make the medium ceramic content mixed powder wrap the core composite ball, so as to obtain an intermediate composite ball with a larger particle size; (3) mixing the intermediate composite ball obtained in step (2) with low ceramic content mixed powder and a binder and performing shot blasting to make the low ceramic content mixed powder wrap the intermediate composite ball, so as to obtain a composite ball with a gradient interface; (4) drying the composite ball in step (3).

2. The method of claim 1, wherein: In the high ceramic content mixed powder, the volume of ceramic powder accounts for 60-80% of the total volume of the mixed powder, and the balance is metal powder; In the medium ceramic content mixed powder, the volume of ceramic powder accounts for 40-60% of the total volume of the mixed powder, and the balance is metal powder; In the low ceramic content mixed powder, the volume of ceramic powder accounts for 20-40% of the total volume of the mixed powder, and the balance is metal powder.

3. The method of claim 1, wherein: In step (2), the mass ratio of the added medium ceramic content mixed powder to the high ceramic content mixed powder added in step (1) is 1:1; in step (3), the mass ratio of the added low ceramic content mixed powder to the medium ceramic content mixed powder added in step (2) is 2:

1.

4. The method of claim 1, wherein: In step (1), the mass of the binder added is 1-5% of the mass of the ceramic powder in the high ceramic content mixed powder; In step (2), the mass of the binder added is 1-5% of the mass of the ceramic powder in the medium ceramic content mixed powder; In step (3), the mass of the binder added is 1-5% of the mass of the ceramic powder in the low ceramic content mixed powder.

5. The method of claim 1, wherein: In steps (1), (2) and (3), the shot blasting speed is 40-80 r / min, and the shot blasting temperature is 80-120 DEG C.

6. The method of claim 1, wherein: In the high ceramic content mixed powder, the medium ceramic content mixed powder and the low ceramic content mixed powder, the types of ceramic powder are the same, and the types of metal powder are the same.

7. A composite sphere having a gradient interface, characterized by: The composite ball is prepared by the preparation method in any one of claims 1-6.

8. Use of the composite ball according to claim 7, characterized in that: The composite ball is used as a reinforcing phase to prepare a ceramic particle reinforced metal matrix composite material with a metal matrix.

Images