阅读说明：本技术 一种镁/羟基磷灰石多孔复合材料的制备方法 (Preparation method of magnesium/hydroxyapatite porous composite material ) 是由 孟增东 张玉勤 罗丽琳 朱斌 李晶莹 于 2020-12-15 设计创作，主要内容包括：本发明公开一种镁/羟基磷灰石多孔复合材料的制备方法,属于生物医用材料技术领域。本发明所述方法为：以金属镁粉和纳米羟基磷灰石为原料,镁粉与纳米羟基磷灰石按质量比1％～10％:99％～90％进行配比,称取,球磨,烘干,研磨后得到复合粉末；将复合粉末与医用级碳酸氢铵按体积百分比40％～60％:60％～40％进行混合,混合均匀压制得到长条状坯体；采用放电等离子烧结制备出镁/羟基磷灰石多孔复合材料。本发明所制备出的复合材料孔隙率在40％～60％和孔径尺寸在100～500μm且可控；根据实际的需求,制备出满足各种不同需求的复合材料,如骨支架、骨填充及硬组织缺损部分的修复材料等。(The invention discloses a preparation method of a magnesium/hydroxyapatite porous composite material, belonging to the technical field of biomedical materials. The method comprises the following steps: taking metal magnesium powder and nano-hydroxyapatite as raw materials, proportioning the magnesium powder and the nano-hydroxyapatite according to the mass ratio of 1-10% to 99-90%, weighing, ball-milling, drying and grinding to obtain composite powder; mixing the composite powder with medical ammonium bicarbonate in the volume ratio of 40-60% to 60-40%, and pressing to obtain long blank; and preparing the magnesium/hydroxyapatite porous composite material by adopting spark plasma sintering. The porosity of the composite material prepared by the invention is 40-60%, and the pore size is 100-500 mu m and is controllable; according to actual requirements, composite materials meeting various different requirements are prepared, such as bone scaffolds, bone filling materials, repair materials for hard tissue defect parts and the like.)

1. The preparation method of the magnesium/hydroxyapatite porous composite material is characterized by comprising the following steps:

(1) selecting metal magnesium powder and nano-hydroxyapatite as raw materials, wherein the mass percent of the magnesium powder is 1-10%, and the mass percent of the nano-hydroxyapatite is 99-90%;

(2) putting the powder weighed in the step (1) into a stainless steel ball milling tank, putting a stainless steel ball milling tank, and vacuumizing the stainless steel ball milling tank, wherein the processes are all finished in a vacuum glove box; after the ball milling is finished, drying and grinding are carried out to obtain composite powder;

(3) mixing the composite powder obtained in the step (2) with medical ammonium bicarbonate powder according to the volume percentage of 40-60% to 60-40%, uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder into the die, placing the die on a press machine for prepressing, and pressing the die into a long-strip-shaped prepressing blank;

(4) putting the strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mold, putting the self-made graphite mold into a discharge plasma sintering furnace, and pumping the vacuum degree in the sintering furnace to 10^-3～10^-4After Pa, heating to 700-900 ℃ at a heating rate of 100-150 ℃/min, preserving heat for 2-3 min, then heating to 800-1000 ℃ at a heating rate of 25-50 ℃/min, and preserving heat for 5-10 min; and after sintering, cooling to room temperature along with the furnace to obtain the magnesium/hydroxyapatite porous composite material.

2. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 1, characterized in that: in the step (1), the purity of the nano-hydroxyapatite is more than or equal to 99.9%, and the particle size is 150-300 nm; the purity of the metal magnesium powder is 99.95-99.99%, and the particle size is 10-20 μm.

3. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 1, characterized in that: the ball milling conditions in the step (2) are as follows: and (3) fixing the stainless steel ball milling tank on a planetary ball mill for 2 hours at a rotating speed of 200-300 r/min, vacuumizing the tank again to 8-10 Pa after the temperature of the tank is reduced to room temperature, and then ball milling for 6-8 hours at a rotating speed of 300-400 r/min.

4. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 3, characterized in that: in the step (2), the ball material ratio of the stainless steel grinding ball to the raw material is 4: 1-3: 1, wherein the grinding ball mass ratio is as follows: a middle ball: the pellet is 2:8:15 to 3:10: 20.

5. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 1, characterized in that: the drying process in the step (2) is carried out in a vacuum drying oven, the vacuum degree of the drying oven is 8-10 Pa, and the drying temperature is 30-40 ℃.

6. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 1, characterized in that: the purity of the ammonium bicarbonate powder in the step (3) is analytical purity, and the particle size is 100-300 mu m; the mixing process is carried out in an argon environment, and the mixer is used for mixing for 20-30 min at a rotating speed of 50-100 r/min.

7. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 1, characterized in that: the pre-pressing process in the step (3) is one-way pressurization, the loading rate is 1-3 KN/min, the pressure is 400-450 MPa, and the pressure is maintained for 20-30 min.

8. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 1, characterized in that: the self-made stainless steel die has the structure that: a cylindrical outer body: phi 75mm multiplied by H30 mm; a rectangular inner cavity: a15mm × b5mm × c30 mm.

9. The method for preparing the magnesium/hydroxyapatite porous composite material according to claim 1, characterized in that: the self-made graphite mold has the structure that: a cylindrical outer body: phi 15.5mm multiplied by H17.5mm; a rectangular inner cavity: a5.5mm. times.b5.5mm. times.17.5 mm; and (3) plugging: phi 10mm multiplied by 10mm is matched with the rectangular inner cavity of the graphite mould.

Technical Field

The invention relates to a preparation method of a magnesium/hydroxyapatite porous composite material, belonging to the preparation technology in the field of biomedical materials.

Background

The biomedical composite material is a biomedical material compounded by two or more different biomedical materials and is mainly used for repairing and replacing human tissues and manufacturing artificial organs. Many of the natural composites are found in nature and in human tissues, for example, human bone is a fiber-reinforced composite of collagen, protein and inorganic substances. The traditional single-kind biomedical materials can well meet the biomedical requirements in some aspects, but can not meet the standards in other aspects, even can generate adverse effects, and can not meet the clinical application. The biomedical material compounded by materials with different properties not only has the properties of component materials, but also can obtain new characteristics which are not possessed by single-component materials.

The Chinese patent with the application number of CN201310031015.X discloses a magnesium or magnesium alloy-porous hydroxyapatite composite material and a preparation method thereof, wherein the preparation method adopts an extrusion casting method, a pressure head is firstly used for applying lower pressure to enable magnesium or magnesium alloy melt to be impregnated into holes of the porous hydroxyapatite, and then higher pressure is applied in the solidification process of the magnesium or magnesium alloy melt to control the structure of the solidified magnesium or magnesium alloy. Clinical practice generally considers that for the porous biomaterial, the macropore size is 400-600 μm, which is beneficial to the growth of blood vessels and bone tissues, the pore size is 50-100 μm, which is beneficial to the migration of osteoblasts in pores, and the communication rate and the communication size among pores are the key to the smooth growth of bone tissues into pores. The template (porous material) is prepared in advance by adopting organic foam, and then the template is prepared by extrusion casting, although the shape and the size of the hole can be accurately designed by the method, a structure with the large hole and the small hole coexisting with the through hole is not prepared; and magnesium or magnesium alloy is easy to be rapidly degraded in body fluid environment, generates gas, induces inflammation and the like.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the magnesium or magnesium alloy-porous hydroxyapatite composite material prepared by the existing method has uneven component structure and risks of inducing inflammation and causing cell toxicity.

The invention prepares the magnesium/hydroxyapatite porous composite material which can meet different requirements by changing the porosity, the pore size and the content of magnesium and adopting a discharge plasma sintering technology, and the biological and mechanical properties of the composite material are closer to those of natural bones.

In order to achieve the above purpose, the present invention provides a preparation method of a magnesium/hydroxyapatite porous composite material, which mainly comprises the following steps:

(1) the magnesium powder and the nano-hydroxyapatite are used as raw materials, wherein the mass percent of the magnesium powder is 1-10%, and the mass percent of the nano-hydroxyapatite is 99-90%.

(2) Putting the powder weighed in the step (1) into a stainless steel ball milling tank, putting a stainless steel ball milling tank, and vacuumizing the stainless steel ball milling tank, wherein the processes are all finished in a vacuum glove box; and after the ball milling is finished, drying and grinding to obtain composite powder.

(3) Mixing the composite powder obtained in the step (2) with medical ammonium bicarbonate powder according to the volume percentage of 40-60% to 60-40%, uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder into the die, placing the die on a press machine for prepressing, and pressing the die into a long-strip-shaped prepressing blank.

(4) Putting the strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mold, putting the self-made graphite mold into a discharge plasma sintering furnace, and pumping the vacuum degree in the sintering furnace to 10^-3～10^-4After Pa, heating to 700-900 ℃ at a heating rate of 100-150 ℃/min, preserving heat for 2-3 min, then heating to 800-1000 ℃ at a heating rate of 25-50 ℃/min, and preserving heat for 5-10 min; and after sintering, cooling to room temperature along with the furnace to obtain the magnesium/hydroxyapatite porous composite material.

Preferably, in the step (1), the purity of the nano-hydroxyapatite is more than or equal to 99.9%, and the particle size is 150-300 nm; the purity of the metal magnesium powder is 99.95-99.99%, and the particle size is 10-20 μm.

Preferably, the ball milling conditions in step (2) of the present invention are: and (3) fixing the stainless steel ball milling tank on a planetary ball mill for 2 hours at a rotating speed of 200-300 r/min, vacuumizing the tank again to 8-10 Pa after the temperature of the tank is reduced to room temperature, and then ball milling for 6-8 hours at a rotating speed of 300-400 r/min.

Preferably, in the step (2) of the invention, the ball-to-material ratio of the stainless steel grinding balls to the raw materials is 4: 1-3: 1, wherein the grinding balls are large balls in mass ratio: a middle ball: the pellet is 2:8:15 to 3:10: 20.

Preferably, the drying process in the step (2) is carried out in a vacuum drying oven, the vacuum degree of the drying oven is 8-10 Pa, and the drying temperature is 30-40 ℃.

Preferably, the purity of the ammonium bicarbonate powder in the step (3) is analytical purity, and the particle size is 100-300 μm; the mixing process is carried out in an argon environment, and the mixer is used for mixing for 20-30 min at a rotating speed of 50-100 r/min.

Preferably, the pre-pressing process in the step (3) is one-way pressurization, the loading rate is 1-3 KN/min, the pressure is 400-450 MPa, and the pressure is maintained for 20-30 min.

Preferably, the self-made stainless steel mold has the following structure: a cylindrical outer body: phi 75mm multiplied by H30 mm; a rectangular inner cavity: a15mm × b5mm × c30 mm.

Preferably, the self-made graphite mold provided by the invention has the following structure: a cylindrical outer body: phi 15.5mm multiplied by H17.5mm; a rectangular inner cavity: a5.5mm. times.b5.5mm. times.17.5 mm; and (3) plugging: phi 10mm multiplied by 10mm is matched with the rectangular inner cavity of the graphite mould.

All mass percentages in the present invention are mass percentages unless otherwise specified.

The invention has the beneficial effects that:

(1) the prior method for preparing the porous biological composite material comprises extrusion casting, a vacuum seepage casting method, a powder metallurgy method, a laser drilling method and the like; the invention is prepared by adopting SPS discharge plasma sintering technology, can effectively avoid HA decomposition, is easy to realize lattice substitution and uniform distribution of active elements, and can quickly melt powder on the surface of a pre-pressing blank at a quick heating rate to form a porous structure which is not easy to change, thereby avoiding adopting a binder and solving the problem of uneven components of the material prepared by the existing preparation method.

(2) The invention can prepare composite materials with different porosities (40-60%) and different pore sizes (100-500 mu m) by adjusting the particle size and the proportion of the pore-forming agent ammonium bicarbonate according to actual needs, thereby meeting the requirements of bone scaffolds, bone filling, repair materials of hard tissue defect parts and the like.

(3) The invention selects hydroxyapatite as a substrate, magnesium powder is added into the hydroxyapatite as the substrate to prepare the magnesium/hydroxyapatite porous composite material, after the magnesium/hydroxyapatite porous composite material is implanted, the hydroxyapatite on the surface of the material is contacted with body fluid, and Ca is passed through²⁺，PO₄ ^3-And OH^-Exchange of (3), gradually dissolving; along with the degradation of the hydroxyapatite, the coated magnesium is slowly exposed, and magnesium ions are slowly released, so that the magnesium is prevented from being rapidly degraded in a body fluid environment, gas is generated, and inflammation is induced; the specific surface area, namely the contact area of the material and body fluid, is controlled by controlling the pore content and the pore size ratio of the material, so that magnesium ions are slowly and permanently released, and the proliferation and differentiation of osteoblasts are continuously stimulated.

Drawings

FIG. 1 is a schematic view of a self-made stainless steel mold according to the present invention;

FIG. 2 is a schematic view of a self-made graphite mold according to the present invention;

FIG. 3 is a surface topography of a magnesium/hydroxyapatite porous composite material prepared in example 2 of the present invention;

FIG. 4 is a 14d mineralization morphology of the magnesium/hydroxyapatite porous composite material prepared in example 2 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments, but the scope of the present invention is not limited to the description.

The self-made stainless steel die provided by the embodiment of the invention has the following structure: a cylindrical outer body: phi 75mm multiplied by H30 mm; a rectangular inner cavity: a15mm xb 5mm xc 30mm, as shown in fig. 1. The self-made graphite mold has the structure that: a cylindrical outer body: phi 15.5mm multiplied by H17.5mm; a rectangular inner cavity: a5.5mm. times.b5.5mm. times.17.5 mm; and (3) plugging: phi 10mm multiplied by 10mm, which is matched with the rectangular inner cavity of the graphite mold, as shown in figure 2.

Example 1

(1) The magnesium powder is prepared from 99.95-99.99% of metal magnesium powder with the particle size of 10-20 microns and 150-300 microns of nano-hydroxyapatite with the particle size of more than or equal to 99.9% as raw materials, wherein the magnesium powder and the nano-hydroxyapatite are mixed according to the mass ratio of 1% to 99%.

(2) Putting the powder weighed in the step (1) into a stainless steel ball milling tank, putting a proper amount of stainless steel grinding balls according to the ball-to-material ratio of 4:1, and vacuumizing to 8Pa, wherein the processes are all finished in a vacuum glove box; fixing the mixture on a planetary ball mill, and carrying out ball milling for 2 hours at the rotating speed of 200 r/min; and after the temperature of the tank body is reduced to room temperature, vacuumizing the tank body again to 8Pa, and then performing ball milling for 6h at the rotating speed of 300/min.

(3) Pouring the slurry obtained in the step (2) into a culture dish in a vacuum glove box, and putting the culture dish into a vacuum drying box, wherein the drying temperature in the box is 35 ℃, and the vacuum degree is 8 Pa; and mixing the composite powder and 50 percent of ammonium bicarbonate according to the volume percentage, wherein the mixing process is carried out in an argon environment, and a mixer is used for mixing for 20min at the rotating speed of 50 r/min.

(4) Uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder obtained in the step (3) into the die, placing the die in a press machine, pressurizing to 400MPa at a pressurizing rate of 1KN/min, maintaining the pressure for 20min, and unloading to obtain a long-strip-shaped prepressing blank.

(5) Putting the strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mold, putting the self-made graphite mold into a discharge plasma sintering furnace, and pumping the vacuum degree in the sintering furnace to 10^-3After Pa; heating to 700 deg.C at a heating rate of 100 deg.C/min, and maintaining for 1 min; then the temperature is raised to 800 ℃ at the heating rate of 50 ℃/min, and the temperature is kept for 5 min. And after sintering, cooling to room temperature along with the furnace to obtain the magnesium/hydroxyapatite porous composite material.

Example 2

(1) The magnesium powder and the nano-hydroxyapatite are proportioned and weighed according to the mass ratio of 3% to 97% by taking metal magnesium powder with the purity of 99.95-99.99% and the particle size of 10-20 microns and the nano-hydroxyapatite with the purity of more than or equal to 99.9% and the particle size of 150-300 microns as raw materials.

(2) Putting the powder weighed in the step (1) into a stainless steel ball milling tank, and putting a proper amount of stainless steel grinding balls according to a ball-to-material ratio of 3:1, wherein the grinding balls are large balls in mass ratio: a middle ball: the pellets are 2:8:15, and are vacuumized to 9Pa, and the processes are finished in a vacuum glove box; fixing the mixture on a planetary ball mill, and carrying out ball milling for 2 hours at the rotating speed of 200 r/min; and after the temperature of the tank body is reduced to room temperature, vacuumizing the tank body again to 9Pa, and then performing ball milling for 8 hours at the rotating speed of 300/min.

(3) Pouring the slurry obtained in the step (2) into a culture dish in a vacuum glove box, and putting the culture dish into a vacuum drying box, wherein the drying temperature in the box is 40 ℃, and the vacuum degree is 10 Pa; and mixing the composite powder and 50 percent of ammonium bicarbonate according to the volume percentage, wherein the mixing process is carried out in an argon environment, and a mixer is used for mixing for 20min at the rotating speed of 50 r/min.

(4) Uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder obtained in the step (3) into the die, placing the die in a press machine, pressurizing to 400MPa at a pressurizing rate of 1KN/min, maintaining the pressure for 20min, and unloading to obtain a long-strip-shaped prepressing blank.

(5) Putting the long-strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mould, and putting the graphite mould into a discharge plasma sintering furnaceIn the middle, the internal vacuum degree of the sintering furnace is pumped to 10^-3After Pa; heating to 700 deg.C at a heating rate of 100 deg.C/min, and maintaining for 1 min; then the temperature is raised to 800 ℃ at the heating rate of 50 ℃/min, and the temperature is kept for 5 min. And after sintering, cooling to room temperature along with the furnace to obtain the magnesium/hydroxyapatite porous composite material.

Example 3

(1) The magnesium powder and the nano-hydroxyapatite are proportioned and weighed according to the mass ratio of 5% to 95% by taking metal magnesium powder with the purity of 99.95-99.99% and the particle size of 10-20 microns and the nano-hydroxyapatite with the purity of more than or equal to 99.9% and the particle size of 150-300 microns as raw materials.

(2) Putting the powder weighed in the step (1) into a stainless steel ball milling tank, and putting a proper amount of stainless steel grinding balls according to a ball-to-material ratio of 3:1, wherein the grinding balls are large balls in mass ratio: a middle ball: the pellets are 2:8:15, and are vacuumized to 10Pa, and the processes are all finished in a vacuum glove box; fixing the mixture on a planetary ball mill, and carrying out ball milling for 2 hours at the rotating speed of 300 r/min; and after the temperature of the tank body is reduced to room temperature, vacuumizing the tank body again to 10Pa, and then performing ball milling for 8 hours at the rotating speed of 400/min.

(3) Pouring the slurry obtained in the step (2) into a culture dish in a vacuum glove box, and putting the culture dish into a vacuum drying box, wherein the drying temperature in the box is 40 ℃, and the vacuum degree is 10 Pa; and mixing the composite powder and ammonium bicarbonate according to the volume percentage of 40 percent to 60 percent under the argon environment in the mixing process, and mixing for 30min by a mixer at the rotating speed of 100 r/min.

(4) Uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder obtained in the step (3) into the die, placing the die in a press machine, pressurizing to 450MPa at a pressurizing rate of 3KN/min, maintaining the pressure for 30min, and unloading to obtain a long-strip-shaped prepressing blank.

(5) Putting the strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mold, putting the self-made graphite mold into a discharge plasma sintering furnace, and pumping the vacuum degree in the sintering furnace to 10^-4After Pa; heating to 700 deg.C at a heating rate of 150 deg.C/min, and maintaining for 3 min; then the temperature is raised to 800 ℃ at the heating rate of 50 ℃/min, and the temperature is kept for 10 min. After sintering, furnace cooling is carried out to room temperature to obtain magnesium/hydroxyapatiteA stone porous composite material.

Example 4

(1) The magnesium powder and the nano-hydroxyapatite are proportioned and weighed according to the mass ratio of 7% to 93% by taking metal magnesium powder with the purity of 99.95-99.99% and the particle size of 10-20 microns and the nano-hydroxyapatite with the purity of more than or equal to 99.9% and the particle size of 150-300 microns as raw materials.

(2) Putting the powder weighed in the step (1) into a stainless steel ball milling tank, and putting a proper amount of stainless steel grinding balls according to a ball-to-material ratio of 3:1, wherein the grinding balls are large balls in mass ratio: a middle ball: the pellets are 2:8:15, and are vacuumized to 10Pa, and the processes are all finished in a vacuum glove box; fixing the mixture on a planetary ball mill, and carrying out ball milling for 2 hours at the rotating speed of 300 r/min; and after the temperature of the tank body is reduced to room temperature, vacuumizing the tank body again to 10Pa, and then performing ball milling for 8 hours at the rotating speed of 400/min.

(3) Pouring the slurry obtained in the step (2) into a culture dish in a vacuum glove box, and putting the culture dish into a vacuum drying box, wherein the drying temperature in the box is 40 ℃, and the vacuum degree is 10 Pa; and mixing the composite powder and ammonium bicarbonate according to the volume percentage of 60 percent to 40 percent under the argon environment in the mixing process, and mixing for 30min by a mixer at the rotating speed of 100 r/min.

(4) Uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder obtained in the step (3) into the die, placing the die in a press machine, pressurizing to 450MPa at a pressurizing rate of 3KN/min, maintaining the pressure for 30min, and unloading to obtain a long-strip-shaped prepressing blank.

(5) Putting the strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mold, putting the self-made graphite mold into a discharge plasma sintering furnace, and pumping the vacuum degree in the sintering furnace to 10^-4After Pa; heating to 700 deg.C at a heating rate of 150 deg.C/min, and maintaining for 3 min; then the temperature is raised to 800 ℃ at the heating rate of 50 ℃/min, and the temperature is kept for 10 min. And after sintering, cooling to room temperature along with the furnace to obtain the magnesium/hydroxyapatite porous composite material.

Example 5

(1) The magnesium powder and the nano-hydroxyapatite are proportioned and weighed according to the mass ratio of 7% to 93% by taking metal magnesium powder with the purity of 99.95-99.99% and the particle size of 10-20 microns and the nano-hydroxyapatite with the purity of more than or equal to 99.9% and the particle size of 150-300 microns as raw materials.

(2) Putting the powder weighed in the step (1) into a stainless steel ball milling tank, and putting a proper amount of stainless steel grinding balls according to a ball-to-material ratio of 3:1, wherein the grinding balls are large balls in mass ratio: a middle ball: the pellets are 2:8:15, and are vacuumized to 10Pa, and the processes are all finished in a vacuum glove box; fixing the mixture on a planetary ball mill, and carrying out ball milling for 2 hours at the rotating speed of 300 r/min; and after the temperature of the tank body is reduced to room temperature, vacuumizing the tank body again to 10Pa, and then performing ball milling for 8 hours at the rotating speed of 400/min.

(3) Pouring the slurry obtained in the step (2) into a culture dish in a vacuum glove box, and putting the culture dish into a vacuum drying box, wherein the drying temperature in the box is 40 ℃, and the vacuum degree is 10 Pa; and mixing the composite powder and 50 percent of ammonium bicarbonate according to the volume percentage, wherein the mixing process is carried out in an argon environment, and a mixer is used for mixing for 30min at the rotating speed of 100 r/min.

(4) Uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder obtained in the step (3) into the die, placing the die in a press machine, pressurizing to 450MPa at a pressurizing rate of 3KN/min, maintaining the pressure for 30min, and unloading to obtain a long-strip-shaped prepressing blank.

(5) Putting the strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mold, putting the self-made graphite mold into a discharge plasma sintering furnace, and pumping the vacuum degree in the sintering furnace to 10^-4After Pa; heating to 700 deg.C at a heating rate of 150 deg.C/min, and maintaining for 3 min; then the temperature is raised to 800 ℃ at the heating rate of 50 ℃/min, and the temperature is kept for 10 min. And after sintering, cooling to room temperature along with the furnace to obtain the magnesium/hydroxyapatite porous composite material.

Example 6

(1) The magnesium powder and the nano-hydroxyapatite are proportioned and weighed according to the mass ratio of 7% to 93% by taking metal magnesium powder with the purity of 99.95-99.99% and the particle size of 10-20 microns and the nano-hydroxyapatite with the purity of more than or equal to 99.9% and the particle size of 150-300 microns as raw materials.

(2) Putting the powder weighed in the step (1) into a stainless steel ball milling tank, and putting a proper amount of stainless steel grinding balls according to a ball-to-material ratio of 3:1, wherein the grinding balls are large balls in mass ratio: a middle ball: the pellets are 2:8:15, and are vacuumized to 10Pa, and the processes are all finished in a vacuum glove box; fixing the mixture on a planetary ball mill, and carrying out ball milling for 2 hours at the rotating speed of 250 r/min; and after the temperature of the tank body is reduced to room temperature, vacuumizing the tank body again to 10Pa, and then performing ball milling for 8h at the rotating speed of 350/min.

(3) Pouring the slurry obtained in the step (2) into a culture dish in a vacuum glove box, and putting the culture dish into a vacuum drying box, wherein the drying temperature in the box is 40 ℃, and the vacuum degree is 10 Pa; and mixing the composite powder and ammonium bicarbonate according to the volume percentage of 40 percent to 60 percent under the argon environment in the mixing process, and mixing for 30min by a mixer at the rotating speed of 100 r/min.

(4) Uniformly coating a proper amount of vaseline on the inner wall of a self-made stainless steel die, adding the mixed powder obtained in the step (3) into the die, placing the die in a press machine, pressurizing to 450MPa at a pressurizing rate of 3KN/min, maintaining the pressure for 30min, and unloading to obtain a long-strip-shaped prepressing blank.

(5) Putting the strip-shaped prepressing blank obtained in the step (4) into a self-made graphite mold, putting the self-made graphite mold into a discharge plasma sintering furnace, and pumping the vacuum degree in the sintering furnace to 10^-4After Pa; heating to 800 deg.C at a heating rate of 150 deg.C/min, and maintaining for 2 min; then the temperature is raised to 1000 ℃ at the heating rate of 50 ℃/min, and the temperature is kept for 5 min. And after sintering, cooling to room temperature along with the furnace to obtain the magnesium/hydroxyapatite porous composite material.

ICP-OES detection is carried out on the magnesium element in the magnesium/hydroxyapatite porous composite material prepared by the implementation, the difference between the sintered magnesium content and the preset content is not large, the magnesium content accords with the expectation, and the specific result is shown in Table 1.

TABLE 1 magnesium element content in magnesium/hydroxyapatite porous composites

Measuring the porosity of the composite material prepared by the implementation by adopting an Archimedes drainage method; the mechanical properties (compressive strength) of the material are tested in a mechanical testing machine according to the GB/T4740-. To ensure that the results are statistically significant, the average is taken over multiple tests. The test results are detailed in table 2.

TABLE 2 porosity and compressive strength of magnesium/hydroxyapatite porous composites

The surface topography of the composite material before and after mineralization is analyzed by a scanning electron microscope, and fig. 3 is a surface topography map of the composite material prepared in example 2 before mineralization, which can be seen as follows: the composite material has a porous structure with three-dimensional interconnection and coexistence of large pores and small pores, the pore content of the composite material is about 46%, the pore size of the large pores is 200-300 mu m, the pore size of the micropores is less than 10 mu m, and the large pores and the small pores are crossed and uniformly distributed; compared with similar composite materials obtained by other methods at present, the preparation process selected by the invention is simpler and controllable, the distribution of magnesium is more uniform, and the purposes of slowly releasing and inducing osteogenesis for a long time and avoiding inflammation and cell toxicity can be achieved; meanwhile, the pore structure of the material is maintained, the specific surface area of the material is increased, the flow of body fluid among the materials is facilitated, and a space and a channel are provided for bone cell adhesion, the growth of blood vessels, the formation of a blood vessel network and the growth of bone tissues.

FIG. 4 is a surface topography of the composite material prepared in example 2 after 14 days of mineralization, and after 14 days of simulated artificial body fluid (SBF) soaking, a large amount of bone-like apatite is deposited on the surface of the composite material, and most of the matrix is covered by apatite. Compared with similar composite materials obtained by other methods at present, the material prepared by the invention has high osteogenesis speed and uniform bone tissue distribution due to more uniform components and structures; meanwhile, the degradation rate of the material is improved by the porous structure and the magnesium coating mode, so that the degradation rate of the material is more matched with the osteogenesis rate.