CN118147503A - Tantalum-diamond mesh structure composite material and additive manufacturing method thereof - Google Patents

Abstract

The embodiment of the application relates to a tantalum-diamond mesh structure composite material and an additive manufacturing method thereof. The composite material comprises: the diamond powder is uniformly distributed in the tantalum matrix, and the distribution of the diamond powder in the tantalum matrix is in a net structure; wherein, the volume ratio of the diamond powder is 10% -40%, and the rest is tantalum matrix; the mesh structure comprises a plurality of mesh cells, each mesh cell being formed from any adjacent two diamond powders. The diamond powder in the composite material of the application forms a grid structure with proper size, and the grid structure not only can prevent dislocation movement of the tantalum matrix and improve the strength of the composite material, but also can keep the deformability of the tantalum matrix in the grid structure, thereby enabling the composite material to obtain good plasticity. And the weight of the composite material is greatly reduced relative to a pure tantalum implant due to the addition of the diamond powder.

Description

Tantalum-diamond mesh structure composite material and additive manufacturing method thereof

Technical Field

The embodiments of the present application relate to the field of additive manufacturing technology, and in particular, to a tantalum-diamond mesh structure composite material and an additive manufacturing method thereof.

Background technique

Tantalum metal is widely used in the biomedical field due to its good biocompatibility, excellent corrosion resistance and ductility, and is known as a "biocompatible" metal. With the rapid growth of the market size of my country's orthopedic implant industry, the market demand for tantalum metal implants is growing. In the context of "precision medicine", there is a demand for customized orthopedic implants in clinical practice, and three-dimensional printing (3D printing) tantalum metal implants have also become bone implant products that the medical and engineering communities are competing to develop. Among them, 3D printing is also known as additive manufacturing.

Compared with titanium alloy, although the density and modulus of tantalum metal are larger, its mechanical properties are lower, which limits its clinical application scope to a certain extent, resulting in porous structures or porous solid composite structures being used only in the field of bone defects. Diamond has the characteristics of high hardness, good wear resistance, excellent antibacterial properties and high biocompatibility. In the biomedical field, chemical vapor deposition is often used to coat diamond film on the surface of metal implants to improve the biocompatibility, antibacterial properties and wear resistance of the implants. However, the chemical vapor deposition method for coating diamond film on the surface of metal implants is complex and costly, which restricts its clinical development.

In the related art, there is no report on medical tantalum-diamond composite materials. And for the preparation method of metal-based diamond composite materials, in the related art, the diamond is first surface treated, and a metal film is plated on its surface before laser 3D printing. For example: a method for preparing diamond copper-based composite materials by an additive manufacturing process with application number CN202010784749.5 discloses first plating a composite coating layer on the surface of diamond powder, wherein the outer coating layer is pure copper, and the inner coating layer is carbide or metal element, and then the plated powder is mixed with copper powder, and integrally formed by laser 3D printing technology, and then sintered and hot isostatically pressed to obtain diamond copper-based composite materials. For another example: a method for preparing high entropy alloy-diamond composite materials based on laser additive manufacturing with application number CN201910538934.3 discloses first obtaining a high entropy alloy matrix powder, mixing it with surface-modified diamond single crystal particles, and then forming it by laser 3D printing technology. Among them, the diamond single crystal particles were surface modified and coated with a Ti/Ni composite film layer.

In the above-mentioned related technologies, due to the poor machinability of diamond particles, they cannot be directly processed or 3D printed, and cannot meet the needs of rapid production of customized implants. When preparing metal-diamond composite materials, due to the poor machinability of diamond particles, the diamond particles need to be surface treated and coated in the early stage, resulting in complex process flow, high processing cost and low production capacity. In addition, due to the high laser reflectivity of metal and diamond particles, the density of metal-composite materials cannot be guaranteed, and hot isostatic pressing and other means are required to eliminate defects. And due to the low energy utilization rate and low power, laser 3D printing technology cannot preheat the powder bed. In addition, the metal cools quickly during the forming process, so that the molten metal cannot completely wrap the diamond particles, affecting the density of the formed parts.

Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field.

Summary of the invention

The purpose of the embodiments of the present application is to provide a tantalum-diamond network structure composite material and an additive manufacturing method thereof, thereby overcoming one or more problems caused by the limitations and defects of the relevant technology at least to a certain extent.

According to a first aspect of an embodiment of the present application, a tantalum-diamond network structure composite material is provided, comprising:

A tantalum matrix and diamond powder, wherein the diamond powder is evenly distributed in the tantalum matrix, and the distribution of the diamond powder in the tantalum matrix is a mesh structure; wherein the volume of the diamond powder accounts for 10% to 40%, and the rest is the tantalum matrix;

The mesh structure includes a plurality of mesh units, and each of the mesh units is formed by any two adjacent diamond powders.

In one embodiment of the present application, the distance between any two adjacent diamond powders is 45-105 μm.

According to a second aspect of an embodiment of the present application, there is provided a method for additive manufacturing of a tantalum-diamond mesh structure composite material, comprising:

The tantalum powder and the diamond powder are ball-milled and mixed according to a preset volume ratio to obtain a ball-milled composite powder, wherein the diamond powder in the composite powder is embedded on the surface of the tantalum powder;

The composite powder is subjected to electron beam selective melting to obtain a tantalum-diamond network structure composite material, comprising:

Preheating the substrate;

and spreading the composite powder onto the preheated substrate to perform powder spreading;

Preheating the composite powder on the substrate according to powder preheating process parameters;

Selectively melting the preheated composite powder according to melting process parameters;

Preheating the powder bed after the selected area is melted according to the powder bed preheating process parameters;

Repeat the above steps of powder spreading, powder preheating, selective melting and powder bed preheating until a tantalum-diamond network structure composite material is obtained.

In one embodiment of the present application, the particle size of the tantalum powder is 45-105 μm, and the particle size of the diamond powder is 1-10 μm.

In one embodiment of the present application, the preset volume ratio of the tantalum powder to the diamond powder is 3:2~9:1.

In one embodiment of the present application, the ball-to-material ratio during ball milling is 2:1-4:1.

In one embodiment of the present application, the powder preheating process parameters include a first scanning current and a first scanning speed, the first scanning current is 25-35 mA, and the first scanning speed is 10-15 m/s.

In one embodiment of the present application, the melting process parameters include a second scanning current and a second scanning speed, the second scanning current is 5-15 mA, and the second scanning speed is 0.1-0.5 m/s.

In one embodiment of the present application, the powder bed preheating process parameters are the same as the powder preheating process parameters.

In one embodiment of the present application, the mixing time during ball milling is 4-6 hours, and the rotation speed is 60-100 r/min.

The technical solution provided by the embodiments of the present application may have the following beneficial effects:

In the embodiment of the present application, through the composite material, the diamond powder in the composite material forms a grid structure of appropriate size, which can not only hinder the dislocation movement of the tantalum matrix and improve the strength of the composite material, but also maintain the deformation ability of the tantalum matrix in the grid structure, so that the composite material can obtain good plasticity. Moreover, due to the addition of diamond powder, the weight of the composite material is greatly reduced compared with pure tantalum implants.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

FIG1 is a schematic diagram showing the structure of a tantalum-diamond network structure composite material in an exemplary embodiment of the present application;

FIG. 2 is a flowchart showing the steps of a method for additively manufacturing a tantalum-diamond network structure composite material in an exemplary embodiment of the present application.

Detailed ways

Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In addition, the drawings are merely schematic illustrations of embodiments of the present application and are not necessarily drawn to scale.

In the related art, due to the high density and low mechanical properties of metallic tantalum, tantalum orthopedic implants are heavy and low in strength, which means that porous tantalum orthopedic implants can only be used in places where the strength requirements are not high, such as bone defects, which limits the scope of clinical application of tantalum orthopedic implants. In the biomedical field, although the biocompatibility and strength of implants can be improved by coating the surface of metal implants with diamond films, the processing cost is high and the processability of diamond particles is poor, so they cannot be directly processed or 3D printed, and therefore cannot meet the needs of rapid production of customized orthopedic implants.

Based on this, a tantalum-diamond mesh structure composite material is first provided in this example embodiment. Referring to FIG1 , the composite material may include: a tantalum matrix and diamond powder, wherein the diamond powder is evenly distributed in the tantalum matrix, and the distribution of the diamond powder in the tantalum matrix is a mesh structure; wherein the volume proportion of the diamond powder is 10% to 40%, and the rest is the tantalum matrix; the mesh structure includes a plurality of mesh units, each of which is formed by any two adjacent diamond powders.

It is understandable that the density of diamond powder is 3.5g/cm ³ , the density of tantalum powder is 16.6g/cm ³ , and the density of diamond powder is about 21% of the density of tantalum powder. Therefore, in the present application, due to the addition of diamond powder, and the volume proportion of diamond powder is preferably 10% to 40%, the weight of the composite material in the present application is greatly reduced relative to the pure tantalum implant. Among them, the volume proportion of diamond powder is 10%, 15%, 20%, 30% or 40%. The specific volume proportion of diamond powder in the composite material can be selected according to actual conditions, and the present application does not limit this.

In the composite material, the diamond powder is evenly distributed in the tantalum matrix, and the distribution of the diamond powder in the tantalum matrix is a mesh structure. In the present application, the diamond powder forms a mesh structure of appropriate size. The mesh structure in the composite material can not only hinder the dislocation movement of the tantalum matrix and improve the strength of the composite material, but also maintain the deformation ability of the tantalum matrix in the mesh structure, so that the composite material has good plasticity.

In the embodiment of the present application, through the composite material, the diamond powder in the composite material forms a grid structure of appropriate size, which can not only hinder the dislocation movement of the tantalum matrix and improve the strength of the composite material, but also maintain the deformation ability of the tantalum matrix in the grid structure, so that the composite material can obtain good plasticity. Moreover, due to the addition of diamond powder, the weight of the composite material is greatly reduced compared with pure tantalum implants.

Next, the above-mentioned tantalum-diamond network structure composite material in this example embodiment will be described in more detail with reference to FIG. 1 .

In one embodiment, the distance between any two adjacent diamond powders is 45-105 μm.

It can be understood that the mesh structure in the present application is formed based on the distribution of diamond powder in the tantalum matrix, and the mesh structure includes a number of grid units, each of which is formed by any two adjacent diamond powders. And the distance between any two adjacent diamond powders is 45~105μm, that is, the length range of the grid unit is 45~105μm. Within the length range of this grid unit, the diamond powder can be distributed in the tantalum matrix to form a grid structure of appropriate size. The grid structure of appropriate size can not only better hinder the dislocation movement of the tantalum matrix and improve the strength of the composite material, but also maintain the deformation ability of the tantalum matrix in the grid structure, so that the composite material has better plastic properties. Among them, the distance between any two adjacent diamond powders is 45μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm or 105μm, etc. The specific distance between any two adjacent diamond powders can be selected according to actual conditions, and this application does not limit this.

In the embodiment of the present application, through the composite material, the diamond powder in the composite material forms a grid structure of appropriate size, which can not only hinder the dislocation movement of the tantalum matrix and improve the strength of the composite material, but also maintain the deformation ability of the tantalum matrix in the grid structure, so that the composite material can obtain good plasticity. Moreover, due to the addition of diamond powder, the weight of the composite material is greatly reduced compared with pure tantalum implants.

In the relevant technologies for preparing metal-diamond composite materials, due to the poor machinability of diamond particles, the diamond particles need to be surface treated and coated in the early stage, resulting in complex process flow, high processing cost and low production capacity. In addition, due to the high laser reflectivity of metal and diamond particles, the density of metal-composite materials cannot be guaranteed, and hot isostatic pressing and other means are required to eliminate defects. And due to the low energy utilization rate and low power, laser 3D printing technology cannot preheat the powder bed. In addition, the metal cools quickly during the forming process, so the molten metal cannot completely wrap the diamond particles, affecting the density of the formed parts.

Based on this, this example embodiment also provides an additive manufacturing method for a tantalum-diamond network structure composite material. Referring to FIG. 2 , the method includes: step S101 to step S102 .

Wherein, step S101: tantalum powder and diamond powder are ball-milled and mixed according to a preset volume ratio to obtain a ball-milled composite powder, in which the diamond powder is embedded on the surface of the tantalum powder.

Step S102: performing electron beam selective melting to form the composite powder to obtain a tantalum-diamond network structure composite material, including:

Preheating the substrate;

and spreading the composite powder onto the preheated substrate to perform powder spreading;

Preheating the composite powder on the substrate according to the powder preheating process parameters;

Selectively melting the preheated composite powder according to melting process parameters;

Preheating the powder bed after the selected area is melted according to the powder bed preheating process parameters;

Repeat the above steps of powder spreading, powder preheating, selective melting and powder bed preheating until a tantalum-diamond network structure composite material is obtained.

It can be understood that the process of preparing tantalum-diamond network structure composite material by additive manufacturing method in the present application mainly includes two parts: powder mixing and electron beam selective melting forming.

During the powder mixing process, tantalum powder and diamond powder are directly ball-milled and mixed in a ball mill at a preset volume ratio of 3:2~9:1 to obtain a composite powder after ball milling. In this application, the particle size of tantalum powder is 45~105μm, and the particle size of diamond powder is 1~10μm. Due to the high hardness of diamond powder and the good plasticity of tantalum powder, diamond powder can be embedded on the surface of tantalum powder during ball milling, thereby ensuring the uniform distribution of diamond powder in the tantalum matrix in the prepared tantalum-diamond mesh structure composite material. Among them, the particle size of tantalum powder is 45μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm or 105μm, etc. The particle size of diamond powder is 1μm, 3μm, 5μm, 8μm or 10μm, etc. The specific particle size of tantalum powder and the specific particle size of diamond powder can be selected according to actual conditions, and this application does not limit this.

It should be noted that the shape of tantalum powder is spherical, and the shape of diamond powder is irregular. The purity of tantalum powder is greater than 99.9%, and the purity of diamond powder is greater than 95%. The ball-to-material ratio during ball milling is 2:1~4:1. The mixing time during ball milling is 4~6h, and the speed is 60~100r/min. By setting the ball-to-material ratio, mixing time and speed during ball milling, better ball milling mixing of tantalum powder and diamond powder can be achieved.

After the tantalum powder and diamond powder are ball-milled and mixed to obtain a composite powder, the composite powder needs to be subjected to electron beam selective melting forming. In electron beam selective melting forming, first, the substrate in the forming chamber must be preheated to a first preset temperature to provide a good temperature environment for the subsequent sintering of the composite powder. Among them, the first preset temperature is 1300°C. Secondly, the composite powder is laid on the preheated substrate to lay the powder. Then, the composite powder laid on the substrate is preheated to a second preset temperature. The second preset temperature can be set according to actual conditions, and this application does not impose any restrictions on this. The powder preheating process parameters during the powder preheating process include a first scanning current and a first scanning speed. The first scanning current is 25~35mA, and the first scanning speed is 10~15 m/s. The first scanning current is 25mA, 30mA, 32mA or 35mA, etc., the first scanning speed is 10m/s, 13m/s or 15m/s, etc. The specific size of the first scanning current and the specific size of the first scanning speed can be selected according to actual conditions, and this application does not limit this. The powder preheating process parameters set in this application can achieve better preheating of the composite powder and make the composite powder undergo preliminary sintering.

After the powder is preheated, the preheated composite powder needs to be selectively melted. The melting process parameters in the selective melting process include a second scanning current and a second scanning speed. The second scanning current is 5~15 mA, and the second scanning speed is 0.1~0.5 m/s. Among them, the second scanning current is 5mA, 8mA, 10mA or 15mA, etc., and the second scanning speed is 0.1m/s, 0.2m/s or 0.5m/s, etc. The specific size of the second scanning current and the specific size of the second scanning speed can be selected according to actual conditions, and this application does not limit this. The melting process parameters set in this application can achieve better selective melting of the preheated composite powder, so that the composite powder can be further sintered.

After the preheated composite powder is selectively melted, the powder bed after the selective melting needs to be preheated. During the powder bed preheating process, the powder bed preheating process parameters are the same as the powder preheating process parameters. Therefore, the powder bed preheating process parameters also include a first scanning current and a first scanning speed, the first scanning current is 25~35mA, and the first scanning speed is 10~15 m/s. In the present application, the powder bed is preheated after the selective melting according to the powder bed preheating process parameters, which can effectively control the cooling rate of the molten tantalum during the forming process, so that the molten tantalum can fully wrap the diamond powder, thereby improving the density of the tantalum-diamond network structure composite material.

After preheating the powder bed after the selective melting, the steps of powder spreading, powder preheating, selective melting and powder bed preheating are repeated until a tantalum-diamond network structure composite material is obtained.

Compared with laser additive manufacturing technology, the tantalum powder in this application has a higher energy absorption rate for electron beams. In addition, the electron beam additive manufacturing technology has the characteristics of high energy density, which can effectively ensure the melting quality of tantalum powder, so that the density of tantalum-diamond network structure composite material is greater than 99.5%. In addition, in the process of preparing tantalum-diamond network structure composite materials in this application, there is no need to perform surface modification and coating on the diamond powder as a pre-treatment. It is only necessary to mix tantalum powder and diamond powder by ball milling to achieve the diamond powder embedded in the surface of tantalum powder, and then perform electron beam additive manufacturing printing. Therefore, this application reduces the process of coating diamond powder in the early stage, reduces costs, and improves production efficiency.

Next, each step in the above method in this example implementation will be described in more detail with reference to FIG. 2 .

In one embodiment, the particle size of the tantalum powder is 45-105 μm, and the particle size of the diamond powder is 1-10 μm.

In one embodiment, the preset volume ratio of tantalum powder to diamond powder is 3:2-9:1.

In one embodiment, the ball-to-material ratio during ball milling is 2:1 to 4:1.

In one embodiment, the powder preheating process parameters include a first scanning current and a first scanning speed, the first scanning current is 25-35 mA, and the first scanning speed is 10-15 m/s.

In one embodiment, the melting process parameters include a second scanning current and a second scanning speed, the second scanning current is 5-15 mA, and the second scanning speed is 0.1-0.5 m/s.

In one embodiment, the powder bed preheating process parameters and the powder preheating process parameters are the same.

In one embodiment, the mixing time during ball milling is 4-6 hours, and the rotation speed is 60-100 r/min.

It should be understood that the terms "first" and "second" in the above description are only used for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" 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 application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application.

Claims (10)

1. A tantalum-diamond mesh composite material comprising:

The diamond powder is uniformly distributed in the tantalum matrix, and the distribution of the diamond powder in the tantalum matrix is in a net structure; wherein the volume ratio of the diamond powder is 10% -40%, and the balance is the tantalum matrix;

The mesh structure comprises a plurality of mesh units, and each mesh unit is formed by any two adjacent diamond powders.

2. The tantalum-diamond mesh composite material according to claim 1, wherein a distance between any two adjacent diamond powders is 45 to 105 μm.

3. A method of additive manufacturing of tantalum-diamond mesh composite materials, comprising:

Ball-milling and mixing tantalum powder and diamond powder according to a preset volume ratio to obtain ball-milled composite powder, wherein the diamond powder in the composite powder is inlaid on the surface of the tantalum powder;

Carrying out electron beam selective melting forming on the composite powder to obtain a tantalum-diamond mesh structure composite material, wherein the method comprises the following steps of:

Preheating a substrate;

paving the composite powder on the preheated substrate to perform powder paving;

carrying out powder preheating on the composite powder on the substrate according to the powder preheating technological parameters;

carrying out zone-selection melting on the preheated composite powder according to melting technological parameters;

Preheating the powder bed after the selective melting according to the powder bed preheating technological parameters;

repeating the steps of laying powder, preheating powder, melting selected areas and preheating a powder bed until the tantalum-diamond mesh structure composite material is obtained.

4. The additive manufacturing method of the tantalum-diamond mesh composite material according to claim 3, wherein the particle size of the tantalum powder is 45-105 μm, and the particle size of the diamond powder is 1-10 μm.

5. The additive manufacturing method of the tantalum-diamond mesh composite material according to claim 3, wherein a preset volume ratio of the tantalum powder to the diamond powder is 3:2-9:1.

6. The additive manufacturing method of the tantalum-diamond mesh composite material according to claim 3, wherein the ball-to-material ratio during ball milling is 2:1-4:1.

7. The additive manufacturing method of the tantalum-diamond mesh composite material according to claim 3, wherein the powder preheating process parameters comprise a first scanning current and a first scanning speed, wherein the first scanning current is 25-35 mA, and the first scanning speed is 10-15 m/s.

8. The additive manufacturing method of the tantalum-diamond mesh composite material according to claim 3, wherein said melting process parameters comprise a second scanning current and a second scanning speed, said second scanning current is 5-15 mA, and said second scanning speed is 0.1-0.5 m/s.

9. A method of additive manufacturing a tantalum-diamond mesh composite material according to claim 3, wherein said powder bed preheating process parameters are the same as said powder preheating process parameters.

10. The additive manufacturing method of the tantalum-diamond mesh structure composite material according to claim 3, wherein the mixing time during ball milling is 4-6 hours, and the rotating speed is 60-100 r/min.