KR102562983B1 - Porous titanium powder, and method for manufacturing of the same - Google Patents

Abstract

The present embodiments relate to a porous titanium-based powder and a manufacturing method thereof.
Porous titanium-based powder according to one embodiment, the porosity may be in the range of 4 to 7 vol%.

Description

Porous titanium-based powder and its manufacturing method {POROUS TITANIUM POWDER, AND METHOD FOR MANUFACTURING OF THE SAME}

The present embodiments relate to a porous titanium-based powder and a manufacturing method thereof, and more specifically, to a porous titanium-based powder having excellent biocompatibility due to high porosity and a manufacturing method thereof.

In the early stage, stainless steel (STS 316) was mainly used as a living implant material. However, it has been pointed out that stainless steel is harmful to the human body because it contains Ni, and that there is a risk of stress corrosion in the living body. Since then, Co-based alloy materials have been interested in biomaterials.

These alloy-based materials generally satisfy the properties required for biomaterials, and have been used for partial denture frames as a substitute for Au alloys, but have poor biocompatibility and low hardness and specific strength compared to excellent corrosion resistance.

Therefore, recently, in the field of orthopedics and dentistry, titanium and titanium alloy materials have been widely used as substitute materials for hard tissues, and methods for improving the compatibility with living bodies and fixation of these materials with living tissues have been developed.

For example, in order to improve the biocompatibility of metal implants such as titanium and titanium alloys, a biocompatible coating method using hydroxyapatite (HA) having low sintering strength and fracture toughness has been proposed. However, the biocompatible coating is expensive to manufacture and has problems in that the coating material is peeled off from the metal surface. In addition, since the coated product has a higher modulus of elasticity than cortical bone, a stress shielding effect is generated by the bone having a low elastic modulus, and this stress shielding has a problem in that the life of the product for living organisms is shortened.

In addition, 3D printing technology is applied to improve compatibility with biological tissues and to manufacture implants tailored to the patient's individual, physical and constitutional inclinations, and spherical titanium-based powder is applied to the 3D printing technology. In general, spherical titanium-based powder is prepared using RF plasma or the like.

However, since the spherical titanium-based powder produced by RF plasma has a smooth surface and the molten laminated surface does not form a mesh structure after 3D printing, it does not promote the generation of regenerated bone.

Therefore, the development of a technology capable of producing a titanium-based powder having excellent biocompatibility of implants is required.

In this embodiment, since it has a high porosity, it is intended to provide a porous titanium-based powder having excellent biocompatibility and a manufacturing method thereof.

The porous titanium-based powder according to one embodiment may have an average porosity in the range of 4 to 7% by volume.

An average diameter of pores included in the porous titanium-based powder may be 1 μm or less.

The elastic modulus of the porous titanium-based powder may be in the range of 30 MPa to 70 MPa.

A method for producing a porous titanium-based powder according to another embodiment includes preparing a titanium-based raw material containing Sn; Plasma treatment of the titanium-based raw material to prepare a spherical powder; Obtaining a reactant by adding a solid phase diffusion reaction raw material to the spherical powder and reacting thereto; And washing the reactant with water to form pores in the titanium-based powder; may include.

The titanium-based raw material may further include at least one of Zr, Nb, and Ni.

In the step of preparing the titanium-based raw material, the content of Sn may be 1% by weight or less based on 100% by weight of the titanium-based raw material.

The preparing of the spherical powder may include: preparing a hydrogenated titanium powder by hydrogenating the titanium-based raw material and then pulverizing; and preparing a spherical powder by plasma-treating the hydrogenated titanium powder.

The solid phase diffusion reaction raw material may include Ca.

Obtaining the reactant may be performed by mixing the spherical powder and the solid phase diffusion reaction raw material in a weight ratio of 1:1 to 2:1 and then contacting them.

Obtaining the reactants may be performed under vacuum conditions of 1x10 ^-4 torr or higher.

Obtaining the reactant may be performed by heat treatment at 700 ° C to 800 ° C for 1 hour or more.

The washing with water may be performed using at least one of distilled water and alcohol.

The porous titanium-based powder manufactured according to one embodiment has excellent biocompatibility when applied to an implant procedure because it is easy to form a network structure due to its low elastic modulus and high porosity.

In addition, it can have excellent light weight, high specific strength, and sound absorption and dustproof properties due to energy absorption capacity, which cannot be expected from ordinary metals.

In addition, it is possible to exhibit functionality such as thermal insulation due to internal pores, heat transfer ability due to through pores, and reaction promotion due to a large surface area.

Therefore, it can be used as a new material applicable to various fields by utilizing the above functions.

1 shows a method for producing a porous titanium-based powder according to an embodiment.
2a to 2d show SEM images of titanium-based powders prepared according to Example 1 and Comparative Example 1.
Figures 3a and 3b simulate the sintering behavior of the titanium-based powder prepared according to Example 1 and Comparative Example 1, respectively.

Terms such as first, second and third are used to describe, but are not limited to, various parts, components, regions, layers and/or sections. These terms are only used to distinguish one part, component, region, layer or section from another part, component, region, layer or section. Accordingly, a first part, component, region, layer or section described below may be referred to as a second part, component, region, layer or section without departing from the scope of the present invention.

The terminology used herein is only for referring to specific embodiments and is not intended to limit the present invention. As used herein, the singular forms also include the plural forms unless the phrases clearly indicate the opposite. The meaning of "comprising" as used herein specifies particular characteristics, regions, integers, steps, operations, elements and/or components, and the presence or absence of other characteristics, regions, integers, steps, operations, elements and/or components. Additions are not excluded.

When a part is referred to as being “on” or “on” another part, it may be directly on or on the other part or may be followed by another part therebetween. In contrast, when a part is said to be “directly on” another part, there is no intervening part between them.

Although not defined differently, all terms including technical terms and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with related technical literature and currently disclosed content, and are not interpreted in ideal or very formal meanings unless defined.

1 shows a method for producing a porous titanium-based powder according to an embodiment.

Referring to FIG. 1, the method for producing a porous titanium-based powder of this embodiment includes preparing a titanium-based raw material containing Sn (S100), and plasma-treating the titanium-based raw material to produce a spherical powder (S200). , Step (S300) of adding a raw material for solid phase diffusion reaction to the spherical powder and then reacting to obtain a reactant (S300), and step (400) washing the reactant with water.

First, step 100 of preparing a titanium-based raw material including Sn is performed.

In this case, the content of Sn may be 1 wt% or less, more specifically greater than 0 and 1 wt% or less, or 0.3 to 0.7 wt% based on 100 wt% of the titanium-based raw material.

The titanium-based raw material may further include at least one of Zr, Nb, and Ni.

In this embodiment, the titanium-based raw material may have a titanium content of 45% by weight or more, more specifically, 45% by weight based on the total titanium-based raw material.

Manufacturing of the titanium-based raw material may be performed by, for example, a method of manufacturing an ingot using arc melting.

In the present specification, "titanium-based powder" may mean a titanium metal powder or an alloy powder containing titanium metal.

Next, a step (S200) of producing spherical powder by plasma-treating the titanium-based raw material is performed.

Specifically, the step of preparing the spherical powder includes the steps of hydrogenating and then pulverizing the titanium-based raw material to produce hydrogenated titanium powder, and plasma-treating the hydrogenated titanium powder to produce spherical powder. can do.

The process of hydrogenating the titanium-based raw material may be performed by heat-treating the titanium-based raw material in a hydrogen atmosphere for a certain period of time.

For example, it may be performed by heating the titanium-based raw material to a temperature range of 450 to 600 ° C. in a hydrogen atmosphere and then maintaining it for 4 to 8 hours. In the case of hydrogenation at less than 450 ° C., it may be difficult to induce hydrogen embrittlement fracture due to low reaction with metal. On the other hand, when hydrogenation is performed at a temperature higher than 600° C., recrystallization of the ingot may occur or grain growth may cause economic loss in a subsequent process.

Thereafter, the hydrogenated titanium-based raw material is pulverized to prepare hydrogenated titanium powder. Hydrogenated titanium-based raw materials can be easily pulverized because hydrogen is injected into them to make them more brittle. This milling process can be carried out in an inert atmosphere. In this case, surface oxidation of the pulverized powder can be prevented.

The pulverization may be performed by various mechanical pulverization methods, such as, for example, jet mill, planetary mill, vibration mill, spex mill, and ball mill. no.

The grinding may be performed in an inert or reducing atmosphere, and more specifically, in an atmosphere containing argon (Ar), nitrogen (N2), helium (He), hydrogen (H2), or a combination thereof it could be Grinding is performed in an inert or reducing atmosphere to prevent oxidation of the powder due to oxygen during crushing.

The pulverized powder after hydrogenation has prismatic particles. Therefore, the hydrogenated titanium-based powder is treated with plasma to improve the sphericity of the powder, and hydrogen and impurities in the powder are removed to increase the purity of the titanium-based powder.

The plasma treatment may be performed in an inert gas atmosphere or a mixed atmosphere of an inert gas and hydrogen (H2) gas. Plasma treatment is performed in an inert gas atmosphere or a mixed atmosphere of an inert gas and hydrogen (H2) gas to prevent oxidation of the powder due to oxygen in the chamber during the plasma treatment. In addition, as the hydrogenated TiH2 prismatic powder becomes Ti spherical powder, the dissociated H2 can act as an oxidation preventing and reducing atmosphere for the powder in the chamber.

Next, a step (S300) of obtaining a reactant by adding a raw material for solid phase diffusion reaction to the spherical powder and reacting thereto is performed.

In this case, the solid phase diffusion reaction raw material may include Ca.

The spherical powder and the solid phase diffusion reaction raw material may be mixed in a weight ratio of 1:1 to 2:1. Specifically, powder may also be used as a raw material for the solid phase diffusion reaction.

The step of obtaining the reactant may be specifically, 1x10 ^-4 torr or more, more specifically, 1 x 10 ^-4 torr to 5 x 10 ^-5 torr may be carried out under vacuum conditions.

In addition, it may be performed by heat treatment at 700 ° C. to 800 ° C. for 1 hour or more, more specifically, 1 hour to 2 hours.

In this embodiment, the solid phase diffusion reaction raw material may be, for example, Ca.

In this way, when the Ca powder is added and heat treated under high vacuum conditions, a solid phase diffusion reaction is induced. Specifically, when Ca undergoes a solid phase diffusion reaction, Sn included in the titanium-based raw material powder forms a Ca ₂ Sn and CaO compound.

When the solid phase diffusion reaction occurs in the high vacuum as described above, Sn inside the titanium-based raw material powder is moved to the surface of the powder, and Sn and Ca directly react on the surface of the powder.

Next, step 400 of forming pores in the titanium-based powder by washing the reactant with water is performed. Water washing may be performed using, for example, at least one of distilled water and alcohol, followed by drying.

In this way, through the water washing and drying process, materials formed on the surface of the powder, such as Ca ₂ Sn and CaO, are removed, and thus pores having an average diameter of 1 μm or less are formed on the surface of the spherical powder.

The porous titanium-based powder of the present embodiment prepared by the above method may have an average porosity in the range of 4 to 7% by volume.

In the present specification, the porosity means the ratio occupied by pores in the total volume of the porous titanium-based powder.

In addition, the average diameter of the pores included in the porous titanium-based powder may be 1 μm or less, more specifically in the range of 400 nm to 800 nm.

The elastic modulus of the porous titanium-based powder of this embodiment may be in the range of 30 MPa to 70 MPa. In addition, compared to the case where only hydrogenation and plasma treatment are performed on the titanium-based raw material and the spherical titanium-based powder is produced without performing the solid-state diffusion reaction process, the surface area of the porous titanium-based powder according to the present embodiment is 5 % to 25%.

When the porous titanium crab powder has a porosity in the above range, it is easy to form a network structure because there are pores on the melt-laminated surface after 3D printing, and thus the generation of regenerated bone can be promoted. That is, the three-dimensionally connected porous titanium-based powder, as in the present embodiment, has excellent biocompatibility because it is easy for the implant to grow into surrounding bone tissue and at the same time maintains mechanical strength for a certain period of time.

In addition, in the case of having the above porosity, physical, mechanical, and thermal properties, as well as other properties, are significantly different from those of dense materials, so excellent lightness, high specific strength, and sound absorption by energy absorption capacity, which cannot be expected from ordinary metals It may have anti-vibration properties. In addition, functionalities such as thermal insulation due to internal pores, heat transfer ability due to through pores, and reaction promotion due to large surface area may be exhibited.

Therefore, by utilizing these functions, it is possible to develop various materials such as ultra-light materials, shock absorbing materials, vibration absorbing materials, soundproofing materials, heat insulating materials, filter materials, heat exchange materials, and biomedical materials. It can be applied to a wide range of fields such as industrial, mechanical, electronic, environmental, and energy industries.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of the claims to be described later.

Example 1

A titanium-based ingot containing titanium and zirconium was prepared using arc melting. At this time, raw materials including Sn were mixed together. Raw materials containing Sn were added so that the content of Sn was 1% by weight or less based on the total weight of the titanium ingot.

Next, the titanium-based ingot containing Sn was charged into a vacuum furnace and then reduced in pressure. Thereafter, hydrogen (H2) gas was sufficiently charged into the furnace, and the furnace temperature was heated to 700° C. or 800° C., followed by hydrogenation for 60 minutes.

After the hydrogenation treatment, the temperature in the furnace was lowered to room temperature (about 25° C.), and then the hydrogenated titanium-based raw material was separated from the furnace and milling was performed using a jet mill. At this time, milling was performed in a mixed atmosphere of nitrogen and argon gas, and the grinding time was 20 minutes.

Thereafter, RF plasma treatment was performed on the hydrogenated titanium-based powder. Plasma treatment was performed in an argon atmosphere.

Then, the plasma-treated titanium-based powder and the Ca powder were mixed at a weight ratio of 1:1, followed by a solid phase diffusion reaction at a vacuum degree of 10 ⁻⁴ torr or higher, at 700° C. to 800° C., and for 1 hour or more.

After the solid phase diffusion reaction was completed, the reactant was washed with distilled water and dried at 80 ° C to prepare a titanium-based powder according to Example 1.

Comparative Example 1

The titanium-based powder according to Comparative Example 1 was prepared by subjecting the plasma-treated titanium-based powder to vacuum heat treatment at a vacuum level of 10 ⁻⁴ torr or higher, 700° C. to 800° C., for 1 hour or more.

Experimental Example 1 - SEM analysis

SEM analysis was performed on the titanium-based powder prepared according to Example 1 and Comparative Example 1, and is shown in FIGS. 2a, 2b, 2c, and 2d.

Figure 2a is a surface photograph of the titanium-based powder prepared according to Example 1, Figure 2c is a cross-sectional photograph.

Figure 2b is a surface photograph of the titanium-based powder prepared according to Comparative Example 1, Figure 2d is a cross-sectional photograph.

Referring to FIGS. 2A to 2D , it can be seen that pores are formed on the surface of the titanium-based powder prepared according to Example 1, but pores are not formed in the titanium-based powder prepared according to Comparative Example 1.

In the titanium-based powder of Example 1, Sn inside the titanium-based raw material reacts with Ca introduced into the process after plasma treatment to move Sn inside the powder to the powder surface, and Sn and Ca react directly on the powder surface to form Ca ₂ Sn, etc. Since the compound and CaO are formed, and these compounds are removed in the washing and drying process, a porous titanium-based powder can be obtained.

However, in the titanium-based powder of Comparative Example 1, since Sn inside the titanium-based raw material formed a compound such as zirconium and an alloy element such as Sn ₃ Zr ₅ , it was not removed even in the water washing process, and thus pores were not formed.

In Figures 3a and 3b, the sintering behavior is simulated using the titanium-based powders of Example 1 and Comparative Example 1. The hatched area indicates the pores of the implant manufactured by sintering or 3D printing, and is an area where surrounding bone tissue can grow when inserted into the human body. Referring to FIG. 3A , it can be seen that the hatched regions are well connected three-dimensionally. In this case, the pores have excellent biocompatibility as bone tissue grows well. The titanium-based powder of FIG. 3a shows a relatively high porosity compared to the titanium-based powder of FIG. 3b, and since it is formed where the necking of powder particles and particles occurs, the formation of bone tissue is excellent and biocompatibility can be improved. .

The present invention is not limited to the above embodiments, but can be manufactured in a variety of different forms, and those skilled in the art to which the present invention pertains may take other specific forms without changing the technical spirit or essential features of the present invention. It will be understood that it can be implemented as. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting.

Claims (12)

delete delete delete Preparing a titanium-based raw material containing Sn;
Plasma treatment of the titanium-based raw material to prepare a spherical powder;
Obtaining a reactant by reacting after adding a solid phase diffusion reaction raw material to the spherical powder; and
forming pores in the titanium-based powder by washing the reactant with water;
including,
The solid-state diffusion raw material is a method for producing a porous titanium-based powder containing Ca. According to claim 4,
The titanium-based raw material is a method for producing a porous titanium-based powder further comprising at least one of Zr, Nb and Ni. According to claim 4,
In the step of preparing the titanium-based raw material,
Method for producing a porous titanium-based powder in which the content of Sn is greater than 0 and 1% by weight or less based on 100% by weight of the titanium-based raw material. According to claim 4,
The step of preparing the spherical powder,
Preparing hydrogenated titanium powder by hydrogenating and pulverizing the titanium-based raw material; and
Plasma treatment of the hydrogenated titanium powder to produce a spherical powder
Method for producing a porous titanium-based powder comprising a. delete According to claim 4,
The step of obtaining the reactant,
A method for producing a porous titanium-based powder, which is performed by mixing the spherical powder and the solid phase diffusion raw material in a weight ratio of 1: 1 to 2: 1 and then contacting them. According to claim 4,
The step of obtaining the reactant,
Method for producing a porous titanium-based powder carried out under vacuum conditions of 1x10 ^-4 torr or more. According to claim 4,
The step of obtaining the reactant,
A method for producing a titanium-based powder performed by heat treatment at 700 ° C to 800 ° C for 1 hour or more. According to claim 4,
The step of washing with water is a method for producing a titanium-based powder performed using at least one of distilled water and alcohol.