CN111233457A - Method for preparing porous magnesium-doped HA-based composite material based on carbon fibers as pore-forming agent and reinforcement - Google Patents

Abstract

The invention discloses a method for preparing a porous magnesium-doped HA-based composite material based on carbon fibers as a pore-forming agent and a reinforcement, which comprises the steps of sequentially carrying out acid treatment and heat treatment on the carbon fibers, and taking T-CF as the pore-forming agent; depositing a Si protective coating on the surface of CF to obtain Si-CF, taking the Si-CF as a reinforcement, taking Mg-doped hydroxyapatite as a matrix, uniformly mixing T-CF, Si-CF and Mg-HA in a certain proportion, forming by using a mould to obtain a mixed blank of the chopped T-CF, Si-CF and Mg-HA, and then obtaining the porous Si-CF reinforced Mg-HA composite material by combining low-temperature pore-forming with high-temperature densification sintering through a two-step method. Micropores with controllable structures and porosity are prepared by using a fiber pore-forming method, mechanical performance indexes such as strength, toughness and the like of the porous composite material are effectively improved through Si-CF, and the microporous structure in the prepared porous CF reinforced magnesium-doped HA-based composite material is beneficial to providing effective nutrient substances to promote cell response.

Description

Method for preparing porous magnesium-doped HA-based composite material based on carbon fibers as pore-forming agent and reinforcement

Technical Field

The invention belongs to the technical field of medical bioceramic, and particularly relates to a method for preparing a porous magnesium-doped HA-based composite material based on carbon fibers as a pore-forming agent and a reinforcement.

Background

With the continuous development of science and technology, the living standard of people is continuously improved, the problem of aging population is more serious, people pay more attention to their health along with the increase of age along with the problem of related diseases and organ decline, which causes the progress of the medical field.

Hydroxyapatite (Ca)₁₀(PO₄)₆(OH)₂HA) is the main matrix composition of natural bone, HAs excellent biocompatibility, bioactivity and osteoconductivity, and is a bone graft repair material with great application prospect. However, after the dense HA is implanted into a human body, the bone plate is only attached to the surface of the HA, large pores for promoting tissue growth to the inside are lacked, and the porous body structure HAs larger specific surface area than the dense body, so that the growth of new bones can be accelerated and the formation of new bones can be induced, and therefore, the porous HA bioceramic is more suitable for bone replacement and bone defect repair. Researches show that the porous HA bioceramics are often used for drug loading and release, chromatographic analysis, in-vivo hard tissue replacement and the like, wherein the most widely applied methods are bone defect repair, such as mandible reconstruction, craniomaxillary bone defect repair and the like, but pure HA HAs high brittleness and low strength, the fracture strength and fracture toughness indexes are lower than those of compact bones of a human body, and the porous structure also causes the reduction of mechanical properties, so that the application of the porous HA bioceramics on the bearing parts of the human body is greatly limited.

In response to the above problems, many researchers have improved the overall mechanical properties of pure HA ceramic materials by introducing a second phase to complex with the HA matrix. Carbon Fiber (CF) has attracted much attention from many researchers as a reinforcing material having a high reinforcing effect due to its advantages such as low density and high specific strength. The CF can effectively control the generation and growth of cracks in the matrix, and greatly improves the comprehensive mechanical property of the composite material. However, the choice of carbon fiber greatly limits the choice of pore-forming method, so that research on the aspect of reinforcing the porous HA stent by the CF is limited.

Disclosure of Invention

Aiming at the problems that the mechanical property of the existing porous bioceramic is poor and the influence of a porous structure on the material property is adverse, the invention provides a method for preparing a porous magnesium-doped HA-based composite material by taking carbon fibers as a pore-forming agent and a reinforcement, so that the quality loss of the reinforcement fiber is ensured to be lower than 15% while the pore-forming fiber is removed in the sintering process of the composite material, and the reinforcement effect of the reinforcement is ensured.

In order to achieve the aim, the invention discloses a method for preparing a porous magnesium-doped HA-based composite material based on carbon fibers as a pore-forming agent and a reinforcement, which comprises the steps of sequentially carrying out acid treatment and heat treatment on carbon fiber CF to obtain T-CF, wherein the T-CF is used as the pore-forming agent; depositing a Si protective coating on the surface of the CF to obtain Si-CF; taking Si-CF as a reinforcement and Mg-doped hydroxyapatite as a matrix, uniformly mixing T-CF, Si-CF and Mg-HA, and performing compression molding to obtain a mixed blank of chopped T-CF, Si-CF and Mg-HA; and then obtaining the porous magnesium-doped HA-based composite material by a two-step method of pore-forming junction and densification sintering.

Further, the method comprises the following steps:

step 1, preparing T-CF, Si-CF and Mg-HA, and specifically comprises the following steps:

1) preparation of T-CF

S1, carrying out mixed acid treatment on the carbon fiber CF after cleaning and removing the glue, wherein the CF after the mixed acid treatment is marked as NHS-CF; soaking NHS-CF in an alkaline solution, reacting for a set time, washing and drying;

s2, sintering a part of NHS-CF after acid mixing treatment for 1h-2h at the temperature of 550-650 ℃, and marking the sintered NHS-CF as T-CF;

2) preparation of Si-CF: winding a part of the CF subjected to acid mixing treatment on an Al plate, and depositing a layer of Si coating on the surface of the CF by adopting a magnetron sputtering method to obtain Si-CF;

3) preparing Mg-HA powder by a hydrothermal synthesis method;

and 2, preparing the porous magnesium-doped HA-based composite material by adopting a normal-pressure two-step sintering method.

Further, step 2 comprises the following steps:

step 2.1, preparing the Si-CF and the T-CF prepared in the step 1 into 2-4mm chopped fibers, uniformly mixing the Mg-HA powder prepared in the step 1 with the sum of the mass of the Si-CF and the mass of the T-CF according to the doping amount of 0.3-0.5 wt%, then pouring the mixture into a mold, and pressing the mixture into round sheets to obtain a T-CF + Si-CF/Mg-HA prefabricated blank body;

step 2.2, placing the T-CF + Si-CF/Mg-HA prefabricated blank obtained in the step 2.1 in a muffle furnace, setting the temperature at 550-;

and 2.3, placing the porous composite material obtained in the step 2.2 in a high-temperature tube furnace, and performing densification sintering, wherein the sintering temperature is 850-.

Further, in step 2.1, when the round sheet materials are pressed, the pressure is 2MPa-4MPa, and the pressure maintaining time is 10min-20 min.

Further, in step 2.3, during densification sintering, nitrogen is introduced into the high-temperature tube furnace, and a protective atmosphere is formed in the furnace chamber.

Further, step 2 comprises the steps of:

s2.1, cutting the Si-CF and the T-CF prepared in the step 1 into 2-4mm chopped fibers, uniformly mixing the Mg-HA powder prepared in the step 1 with the total mass of the Si-CF and the T-CF according to the doping amount of 0.3-0.5 wt%, then pouring the mixture into a mold, and pressing the mixture into round sheets to obtain T-CF + Si-CF/Mg-HA prefabricated blanks;

s2.2, placing the T-CF + Si-CF/Mg-HA prefabricated blank prepared in the step S2.1 in a hot pressing furnace for densification sintering, wherein the sintering temperature is 850-900 ℃, the temperature is kept for 360min when the temperature reaches the maximum, and the heating and cooling rates are set to be 10-15 ℃/min, so as to obtain the T-CF + Si-CF/Mg-HA composite material;

and S2.3, sintering the T-CF + Si-CF/Mg-HA composite material obtained in the step S2.2 in a muffle furnace at 550-700 ℃ for 120-260min to obtain the porous Si-CF/Mg-HA composite material.

Compared with the prior art, the invention has at least the following beneficial technical effects:

1) the method for preparing the porous ceramic by adding the pore-forming agent (T-CF) is high in economy and simple to operate, the used composite powder Mg-HA is prepared by a reagent, wherein the CF realizes mass production, and PAN-based carbon fibers produced by Tohon Tenax Co.

2) Compared with other pore-making methods, the method adopts T-CF as the pore-forming agent to make pores, the porous structure is determined by the type of the pore-forming agent, the pore distribution is uniform, the process is simple, and the porosity is determined by the addition amount of the pore-forming agent.

3) The porous material prepared by the invention has uniform pores and consistent structure, the pore size is 5-7 mu m, the higher open porosity is 30-40%, and the microporous structure of the porous material is helpful for providing effective nutrient substances to promote cell response.

4) Compared with other reinforcements such as glass fibers, the Si-CF with remarkable reinforcing effect is added into the porous ceramic, meanwhile, the HA matrix is doped with Mg, the compression strength of the porous ceramic is obviously improved compared with that of other porous HA with the same porosity, and the research result shows that the compression strength of the porous Si-CF/Mg-HA composite material prepared by the normal pressure method is as follows: 45.04MPa, a porosity of 30% measured by a drainage method, and a porosity of 44% measured by a heating method; J.Antita Lett et al adopt polymerization replication method to prepare porous Hydroxyapatite (HAP) scaffold, and the result shows that the maximum achievable compressive strength of C21200 sample is 2.954MPa (porosity is 40.75%), which is equivalent to that of cancellous bone, so the compressive strength of the invention is obviously improved. The research of Simulated Body Fluid (SBF) shows that the biological material shows good biological performance in an in-vitro environment, is expected to be applied in the field of biomedical materials for repairing bone defects, and lays a foundation for the clinical application of a human body bearing part.

Drawings

FIG. 1a is a microtopography SEM image of acid treated CF;

FIG. 1b is a SEM image of the microstructure of Si-CF;

FIG. 2a is a micro-topography of the porous structure portion of the composite material prepared in example 1;

FIG. 2b is a micro-topography of the remainder of the composite reinforcing fiber made in example 1;

FIG. 3 is an XRD pattern of a porous Si-CF/Mg-HA composite;

FIG. 4a is a graph of the compressive strength of a porous composite;

FIG. 4b is a graph of displacement versus load for a porous composite;

FIG. 5 is a graph of open porosity of a porous composite;

FIG. 6a is an SEM image of a porous Si-CF/Mg-HA composite after soaking for 1 day of SBF;

FIG. 6b is an SEM image of the porous Si-CF/Mg-HA composite after soaking for 3 days of SBF.

In FIGS. 4a, 4b and 5, 0.1% T-CF/1Mg-HA is represented by 0.1% (T-CF), 0.2% T-CF/1Mg-HA is represented by 0.2% (T-CF), 0.3% T-CF/1Mg-HA is represented by 0.3% (T-CF), 0.2% T-CF + 0.3% Si-CF/1Mg-HA ① is represented by 0.3% (Si-CF) + 0.2% (T-CF) ①, and 0.2T-CF + 0.3% Si-CF/1Mg-HA ② is represented by 0.3% (Si-CF) + 0.2% (T-CF) ②.

Detailed Description

In order to make the objects and technical solutions of the present invention clearer and easier to understand. The present invention will be described in further detail with reference to the following drawings and examples, wherein the specific examples are provided for illustrative purposes only and are not intended to limit the present invention.

Mg²⁺As an important cation in human body, the existence of the cation can influence the formation (stimulating the proliferation of osteoblast) and the resorption of bone in osteocyte or bone mineral to a certain extent, can improve the biological performance of the composite material, and also can improve the biological performance of the composite materialCan play a role of reinforcing body. The method takes Mg-doped HA (Mg-HA) as a matrix, acid treatment and heat treatment combined carbon fiber (T-CF) as a pore-forming agent, Si coating carbon fiber (Si-CF) as a reinforcement, and a pore-forming sintering two-step method is selected to prepare the porous Si-CF reinforced magnesium-doped HA-based (Si-CF/Mg-HA) biological ceramic material.

The invention prepares the porous body according to the pore-forming principle of the pore-forming agent (T-CF), CF is treated by two different treatments, namely CF surface modification treatment, namely the CF is treated by a mixed acid treatment and heat treatment method, so that the CF has certain mechanical properties, and the T-CF is obtained to be used as the pore-forming agent; a layer of Si coating with controllable thickness and shape is deposited on the surface of the CF by magnetron sputtering equipment, and Si-CF is obtained to be used as a reinforcing material, so that the quality loss of the reinforcing fiber is ensured to be lower than 15% while the pore-forming fiber is removed from the composite material in the sintering process, and the reinforcing effect of the CF is improved. The porous Si-CF reinforced magnesium-doped HA-based composite material with excellent mechanical property is prepared by combining low-temperature pore-forming with high-temperature densification sintering through a two-step method.

A method for preparing a porous magnesium-doped HA-based composite material based on carbon fibers as a pore-forming agent and a reinforcement comprises the following steps:

step 1, mixed acid treatment and heat treatment of CF

Step 1.1, Mixed acid treatment

The method comprises the following steps of sequentially cleaning CF in an ultrasonic cleaner by using purified water, absolute ethyl alcohol, acetone and distilled water to remove glue, wherein the cleaning setting parameters of the ultrasonic cleaner are as follows: frequency (60.0KHz), power (80.0W), cleaning time (30.0 min);

completely soaking the cleaned and degummed CF in prepared nitric acid (HNO) with the mass fraction of 20 wt%₃) Hydrochloric acid (HCl) and sulfuric acid (H)₂SO₄) Mixed acid solution (NHS) mixed according to the ratio of 1:1:1, then standing and reacting for 2-3h at room temperature, and then washing with water. The CF after acid mixing treatment is marked as NHS-CF;

and finally, completely soaking NHS-CF in 3.0mol/L sodium hydroxide solution, carrying out acid-base neutralization reaction at 80-90 ℃ for 12-24 h, taking out, washing with distilled water, and drying in a drying oven at 60 ℃ for 2-3 h.

Step 1.2, Heat treatment

Sintering the NHS-CF treated in the step 1.1 in a muffle furnace without atmosphere protection at 550-650 ℃ for 1-2h, wherein the mass loss is about 30-40 wt%, certain mechanical property is kept, and the NHS-CF subjected to heat treatment is marked as a T-CF fiber bundle.

Step 2, preparing Si-CF fiber bundle by magnetron sputtering method

Winding the CF treated in the step 1.1 on an Al plate, and depositing a Si coating with controllable thickness and appearance and better oxidation resistance on the surface of the CF by adopting a magnetron sputtering method;

the sputtering power is 160W, the sputtering time is 1-2h, the thickness of the coating is 0.5-1 μm, the coating is uniform, compact, smooth and flat, the CF fiber and the Si coating have good bonding force, and the Si coating basically does not fall off.

Step 3, preparing Mg-HA powder by hydrothermal synthesis method

(10-x)Ca²⁺+xMg²⁺+6PO₄ ^3-+2OH^-

→Ca_(10-x)Mg_x(PO₄)₆(OH)(0≤x≤2)

In the Mg-HA powder selected by the invention, the doping amount of Mg is 0-2, namely 1Mg-HA and 2Mg-HA, and the 1Mg-HA and 2Mg-HA have better mechanical property and biological property.

Step 4, preparing the porous magnesium-doped HA-based composite material Si-CF/Mg-HA by a normal-pressure two-step sintering method, wherein the preparation can be completed by the following two schemes:

the first scheme is as follows: pore-forming and dense sintering

(1) Preparing a blank body: cutting Si-CF and T-CF fiber bundles with the diameter of 7-10 mu m into chopped fibers with the diameter of 2-4mm, uniformly mixing the chopped fibers Si-CF and T-CF with the Mg-HA powder prepared in the step (3) in a mortar to obtain a mixture A, and pouring the mixture A into a stainless steel mold, wherein the sum of the mass of the chopped fibers Si-CF and T-CF accounts for 0.3-0.5 wt% of the whole mixture A;

(2) maintaining the pressure on a single-shaft press at 2-4MPa for 10-20min, pressing into a wafer material with the diameter of 10 multiplied by 2mm, and then unloading by adopting an unloading mould to obtain a T-CF + Si-CF/Mg-HA prefabricated blank body;

(3) and (3) pore forming under normal pressure: placing the prefabricated blank in the previous step into a muffle furnace, setting the temperature at 550-;

(4) and (3) sintering under normal pressure: and (3) placing the porous composite material obtained in the previous normal-pressure pore-forming stage in a high-temperature tube furnace, introducing flowing nitrogen into the tube, forming a protective atmosphere in the furnace chamber, performing densification sintering, wherein the sintering temperature is 850-900 ℃, the temperature is kept for 30-60min when the temperature reaches the maximum, the heating and cooling rates are set to be 10-15 ℃/min, and T-CF is completely removed, so that the porous Si-CF/Mg-HA composite material is finally obtained, and the porous Si-CF/Mg-HA composite material HAs a higher porosity of 30-35% measured by a drainage method (as shown in figure 5) and is favorable for effectively providing nutrient substances.

Scheme II: compact sintering and pore forming

1) Preparing a prefabricated blank body: the method for preparing the preform according to the first scheme is the same as that for preparing the preform according to the first scheme;

2) and (3) sintering under normal pressure: directly placing the green body prepared in the last step into a hot pressing furnace for pressureless sintering, forming a vacuum environment in the hot pressing furnace, performing densification sintering, wherein the sintering temperature is 850-900 ℃, the temperature is kept for 180-360min when the temperature reaches the maximum, and the heating and cooling rates are both set to be 10-15 ℃/min, so as to obtain the T-CF + Si-CF/Mg-HA composite material;

3) and (3) pore forming under normal pressure: sintering the T-CF + Si-CF/Mg-HA composite material in the last step in a muffle furnace at 550-700 ℃ for 260min, wherein about 1/3 remains in the T-CF, so that the porous Si-CF/Mg-HA composite material is obtained, HAs good mechanical properties (the compressive strength is 45-50MPa), and is suitable for a certain bearing environment.

Example 1

A preparation method of a porous Si-CF reinforced magnesium-doped HA-based composite material comprises the following steps:

step 1, mixed acid treatment and heat treatment of CF

Step 1.1, Mixed acid treatment

The method comprises the following steps of sequentially cleaning CF in an ultrasonic cleaner by using purified water, absolute ethyl alcohol, acetone and distilled water to remove glue, wherein the cleaning setting parameters of the ultrasonic cleaner are as follows: frequency (60.0KHz), power (80.0W), cleaning time (30.0 min);

completely soaking the cleaned and degummed CF in prepared nitric acid (HNO) with the mass fraction of 20 wt%₃) Hydrochloric acid (HCl) and sulfuric acid (H)₂SO₄) Mixed acid solution (NHS) according to the ratio of 1:1:1, then standing and reacting for 3h at room temperature, and then washing with water. The CF after acid mixing treatment is marked as NHS-CF;

and finally, completely soaking the NHS-CF in 3.0mol/L sodium hydroxide solution, carrying out acid-base neutralization reaction at 85 ℃ for 12-24 h, taking out, washing with distilled water, and drying in a drying oven at 60 ℃ for 2.5 h. The resulting acid treated CF microtopography SEM image is shown in fig. 1a, from which it can be seen that: the CF is corroded by acid to form an obvious groove, the specific surface area of the CF is increased, a large area is provided for deposition of Si ions, meanwhile, a large number of active oxygen-containing functional groups are generated on the surface of the CF after acid treatment, a large number of active sites are provided for adhesion of a Si coating, and the coating can be effectively prevented from falling off; for pore-forming, the fiber treated by acid is subjected to certain corrosion damage, and then is subjected to further heat treatment and oxidation damage.

Step 1.2, Heat treatment

Sintering a part of the NHS-CF treated in the step 1.1 in a muffle furnace without atmosphere protection at 550-650 ℃ for 1.5h, wherein the NHS-CF after heat treatment is marked as a T-CF fiber bundle; wherein the T-CF used has a mass loss of about 40 wt%;

step 2, preparing Si-CF fiber bundle by magnetron sputtering method

Winding a part of the CF treated in the step 1.1 on an Al plate, and depositing a Si coating with controllable thickness and appearance and better oxidation resistance on the surface of the CF by adopting a magnetron sputtering method; the sputtering power is 160W, the sputtering time is 2h, the thickness of the coating is 0.5-1 μm, the coating is uniform, compact, smooth and flat, the CF fiber and the Si coating have good bonding force, and the Si coating basically does not fall off. Si-CF has a Si coating thickness of about 0.5-1 μm and a deposition time of 2h, and is shown in FIG. 1 b: it can be seen from the top of the fiber that there is an obvious Si coating that is ubiquitous, and the sputtered coating is uniform, dense, smooth and flat.

Step 3, preparing 1Mg-HA powder by a hydrothermal synthesis method;

step 4, preparing the porous Si-CF/Mg-HA composite material, comprising the following steps: step 4.1, uniformly mixing the chopped Si-CF, the chopped T-CF and the matrix powder 1Mg-HA to prepare a T-CF + Si-CF/Mg-HA green compact; wherein the mass fraction of the chopped Si-CF is 0.3 wt% of the matrix powder, and the mass fraction of the chopped T-CF is 0.2 wt% of the matrix powder, and the mass fraction of the chopped T-CF is 2-3 mm; and keeping the pressure for 10min by using a stainless steel die with the diameter of 10mm under the pressure of 2MPa on a manual press machine to obtain a prefabricated blank.

And 4.2, sintering by a two-step method: placing the prefabricated blank prepared in the step 4.1 in a muffle furnace, and preserving the heat for 180min at the temperature of 600 ℃; most of T-CF is oxidized when the temperature is kept for 180min, the residual part is continuously oxidized in the densification sintering stage of the tubular furnace, the densification sintering is carried out for 30min at 850 ℃, and a small amount of T-CF remains. (in examples 2-5, T-CF HAs been substantially oxidized when incubated at 600 ℃ for 260 min.) the microstructure of the porous Si-CF/Mg-HA composite prepared by two-step sintering is shown in FIGS. 2a and 2b, as can be seen in FIG. 2 a: the pore size is 4-7 μm, as can be seen in FIG. 2 b: the size of Si-CF is 2-5 μm. The phase composition of the composite material is shown in fig. 3, and it can be seen from fig. 3 that: the main components of the composite material comprise HA and Ca₃Si₂O₇And MgSiO₃HA is mainly synthesized into a main phase by a hydrothermal method, and Mg-HA is decomposed along with the increase of temperature, MgSiO₃Is formed by reaction of doping of a small amount of Mg element with the presence of Si phase, Ca₃Si₂O₇Generated because the presence of the Si coating forms SiO₂。

The procedures of examples 2-13 are the same as those of example 1, and some parameters are different, and the following description will be made by listing different parameters from example 1, and will be described in table 1.

TABLE 1 raw material ratios and process conditions for comparative examples 1-6 and examples 2-7 of the present invention

Mechanical property testing of the porous Si-CF/Mg-HA composite revealed that the process conditions of example 5, with the addition of 0.3 wt% Si-CF and 0.2 wt% T-CF (0.3% Si-CF + 0.2% T-CF)^②) The compressive strength of the porous composite material is improved by 22.4% compared with that of pure porous Mg-HA, the compressive strength values of examples 1-5 are shown in fig. 4a and 4b, and the prepared porous composite material HAs good reinforcing effect on Si-CF while the porosity is ensured. Example 1 is the best case in preparing porous Si-CF/Mg-HA by a normal pressure two-step sintering method, and example 6 HAs a compressive strength value of 45-50 MPa.

Aiming at the problems that the mechanical property of the existing porous bioceramic is poor and the porous structure HAs adverse influence on the material performance, the invention discloses a preparation method for preparing a porous magnesium-doped HA-based composite material based on carbon fibers as a pore-forming agent and a reinforcement, wherein the Carbon Fibers (CF) are subjected to acid treatment and heat treatment (T-CF) in sequence, and the T-CF is used as the pore-forming agent; depositing a Si protective coating (Si-CF) on the surface of CF, taking the Si-CF as a reinforcement, taking Mg-doped hydroxyapatite (Mg-HA) as a matrix, uniformly mixing T-CF, Si-CF and Mg-HA in a certain proportion, forming by using a mould to obtain a mixed blank (T-CF + Si-CF/Mg-HA) of the chopped T-CF, Si-CF and Mg-HA, and then carrying out low-temperature pore-forming combined with high-temperature densification sintering to obtain the porous Si-CF reinforced Mg-HA composite material (Si-CF/Mg-HA).

The invention has the advantages that: micropores with controllable structures and porosity are prepared by using a fiber pore-forming method, and mechanical performance indexes such as compression strength and the like of the porous composite material are effectively improved through Si-CF: the compressive strength is increased by 22.4% compared with pure porous Mg-HA, as shown in FIG. 4a, the prepared porous CF reinforced magnesium-doped HA-based composite material HAs a microporous structure which helps to provide effective nutrients to promote cellular response, the size of the microporous structure is 4-7 μm, as shown in FIG. 2a, the microporous structure is uniformly distributed in the matrix, the size of Si-CF is 2-5 μm, as shown in FIG. 2b, and the porosity is 30-35 wt% as measured by a drainage method, as shown in FIG. 5; the porous body structure has a larger specific surface area than a dense body, provides a larger space for apatite generation, and is beneficial to bone defect repair. The invention provides the CF reinforced porous bioceramic for the first time, improves the poor performance of the porous bioceramic, is expected to be applied to the field of biomedical materials for repairing bone defects, and lays a foundation for expanding the application of the porous CF reinforced HA-based composite material to the bearing part of a human body.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims (6)

1. A method for preparing a porous magnesium-doped HA-based composite material based on carbon fibers as a pore-forming agent and a reinforcement is characterized in that carbon fiber CF is subjected to acid treatment and heat treatment in sequence to obtain T-CF, and the T-CF is used as the pore-forming agent; depositing a Si protective coating on the surface of the CF to obtain Si-CF; taking Si-CF as a reinforcement and Mg-doped hydroxyapatite as a matrix, uniformly mixing T-CF, Si-CF and Mg-HA, and performing compression molding to obtain a mixed blank of chopped T-CF, Si-CF and Mg-HA; and then obtaining the porous magnesium-doped HA-based composite material by a two-step method of pore-forming junction and densification sintering.

2. The method for preparing the porous magnesium-doped HA-based composite material based on the carbon fibers as the pore-forming agent and the reinforcement as claimed in claim 1, comprising the steps of:

step 1, preparing T-CF, Si-CF and Mg-HA, and specifically comprises the following steps:

1) preparation of T-CF

S1, carrying out mixed acid treatment on the carbon fiber CF after cleaning and removing the glue, wherein the CF after the mixed acid treatment is marked as NHS-CF; soaking NHS-CF in an alkaline solution, reacting for a set time, washing and drying;

s2, sintering a part of NHS-CF after acid mixing treatment for 1h-2h at the temperature of 550-650 ℃, and marking the sintered NHS-CF as T-CF;

2) preparation of Si-CF: winding a part of the CF subjected to acid mixing treatment on an Al plate, and depositing a layer of Si coating on the surface of the CF by adopting a magnetron sputtering method to obtain Si-CF;

3) preparing Mg-HA powder by a hydrothermal synthesis method;

and 2, preparing the porous magnesium-doped HA-based composite material by adopting a normal-pressure two-step sintering method.

3. The method for preparing the porous magnesium-doped HA-based composite material based on the carbon fibers as the pore-forming agent and the reinforcement as claimed in claim 1, wherein the step 2 comprises the steps of:

step 2.1, preparing the Si-CF and the T-CF prepared in the step 1 into 2-4mm chopped fibers, uniformly mixing the Mg-HA powder prepared in the step 1 with the sum of the mass of the Si-CF and the mass of the T-CF according to the doping amount of 0.3-0.5 wt%, then pouring the mixture into a mold, and pressing the mixture into round sheets to obtain a T-CF + Si-CF/Mg-HA prefabricated blank body;

step 2.2, placing the T-CF + Si-CF/Mg-HA prefabricated blank obtained in the step 2.1 in a muffle furnace, setting the temperature at 550-;

and 2.3, placing the porous composite material obtained in the step 2.2 in a high-temperature tube furnace, and performing densification sintering, wherein the sintering temperature is 850-.

4. The method for preparing the porous magnesium-doped HA-based composite material based on carbon fiber as the pore-forming agent and the reinforcement according to claim 3, wherein in the step 2.1, the pressure is 2MPa-4MPa and the pressure holding time is 10min-20min when the material is pressed into the round piece.

5. The method for preparing the porous magnesium-doped HA-based composite material based on carbon fibers as the pore-forming agent and the reinforcement as claimed in claim 3, wherein in the step 2.3, during the densification sintering, nitrogen is introduced into a high temperature tube furnace to form a protective atmosphere in the furnace chamber.

6. The method for preparing the porous magnesium-doped HA-based composite material based on the carbon fibers as the pore-forming agent and the reinforcement as claimed in claim 2, wherein the step 2 comprises the following steps:

s2.1, cutting the Si-CF and the T-CF prepared in the step 1 into 2-4mm chopped fibers, uniformly mixing the Mg-HA powder prepared in the step 1 with the total mass of the Si-CF and the T-CF according to the doping amount of 0.3-0.5 wt%, then pouring the mixture into a mold, and pressing the mixture into round sheets to obtain T-CF + Si-CF/Mg-HA prefabricated blanks;

s2.2, placing the T-CF + Si-CF/Mg-HA prefabricated blank prepared in the step S2.1 in a hot pressing furnace for densification sintering, wherein the sintering temperature is 850-900 ℃, the temperature is kept for 360min when the temperature reaches the maximum, and the heating and cooling rates are set to be 10-15 ℃/min, so as to obtain the T-CF + Si-CF/Mg-HA composite material;

and S2.3, sintering the T-CF + Si-CF/Mg-HA composite material obtained in the step S2.2 in a muffle furnace at 550-700 ℃ for 120-260min to obtain the porous Si-CF/Mg-HA composite material.

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