阅读说明：本技术 一种生物泡沫镁合金的制备方法 (Preparation method of biological foam magnesium alloy ) 是由 罗小萍 史义轩 张健 康丽 黄闻占 刘宝胜 于 2021-01-26 设计创作，主要内容包括：本发明公开了一种生物泡沫镁合金的制备方法,属于泡沫合金制造技术领域,包括以下步骤：将镁合金粉末、碳酸锌及碳酸钙球粒干燥后混合、冷压、烧结得到所述泡沫镁合金；本发明的发泡剂采用以碳酸锌和碳酸钙粗粉和细粉构成芯壳结构的球粒,其不仅解决了孔洞分布不均匀的问题,还解决了碳酸钙使用过多带来的腐蚀性问题；本发明的制备方法可得到均匀孔隙的泡沫镁合金,具有合适的孔隙率,孔径分布均匀；利用粉末冶金法烧结,避免了熔炼的困难,适合于大规模工业化生产；本发明制备得到的泡沫镁合金含对人体有益的元素Mg、Zn、Ca,所得到的材料性能优异,符合生物材料的应用要求,是一种具有良好应用前景的生物泡沫镁合金。(The invention discloses a preparation method of a biological foam magnesium alloy, belonging to the technical field of foam alloy manufacture and comprising the following steps: drying magnesium alloy powder, zinc carbonate and calcium carbonate spherulites, mixing, cold pressing and sintering to obtain the foam magnesium alloy; the foaming agent adopts the spherulites with the core-shell structure formed by zinc carbonate, calcium carbonate coarse powder and fine powder, which not only solves the problem of uneven hole distribution, but also solves the problem of corrosivity caused by excessive use of calcium carbonate; the preparation method can obtain the foam magnesium alloy with uniform pores, has proper porosity and uniform pore size distribution; sintering by using a powder metallurgy method avoids the difficulty of smelting and is suitable for large-scale industrial production; the foam magnesium alloy prepared by the invention contains Mg, Zn and Ca which are beneficial to human bodies, and the obtained material has excellent performance, meets the application requirements of biological materials, and is a biological foam magnesium alloy with good application prospect.)

1. The preparation method of the biological foam magnesium alloy is characterized by comprising the following steps of:

and drying the zinc carbonate, the calcium carbonate spherulites and the magnesium alloy powder, mixing, cold pressing and sintering to obtain the foam magnesium alloy.

2. The method according to claim 1, wherein the magnesium content of the magnesium alloy powder is not less than 75 wt%.

3. The method according to claim 1, wherein the particle size of the magnesium alloy powder is 80 mesh or larger.

4. The method of manufacturing according to claim 1, wherein the zinc carbonate and calcium carbonate pellets have a core of zinc carbonate coarse powder and calcium carbonate coarse powder, and a shell of zinc carbonate fine powder and calcium carbonate fine powder;

the particle sizes of the zinc carbonate coarse powder and the calcium carbonate coarse powder are both larger than 100 meshes and smaller than 140 meshes; the granularity of the zinc carbonate fine powder and the calcium carbonate fine powder is more than or equal to 140 meshes.

5. The method of claim 4, wherein the zinc carbonate and calcium carbonate pellets are prepared by: mixing zinc carbonate coarse powder and calcium carbonate coarse powder to obtain a mixture A; mixing the zinc carbonate fine powder and the calcium carbonate fine powder to obtain a mixture B; kneading 62-80 wt% of the mixture A and 20-38 wt% of a polyvinyl alcohol aqueous solution, and extruding by using an extruder to obtain particles; the granules were then placed in mixture B and rolled to give pellets.

6. The method according to claim 5, wherein the concentration of the aqueous polyvinyl alcohol solution is 5 wt%.

7. The method of claim 4, wherein the zinc carbonate and calcium carbonate pellets have a particle size of 1 to 3 mm.

8. The preparation method according to claim 1, wherein the mass ratio of the zinc carbonate and calcium carbonate pellets to the magnesium alloy powder is 1: 8-10, and the mass ratio of the zinc carbonate and the calcium carbonate in the zinc carbonate and calcium carbonate pellets is 3-5: 1.

9. The production method according to claim 1, wherein the cold pressing is performed at room temperature, at a pressure of 40MPa, and at a dwell time of 3 to 4 min.

10. The preparation method according to claim 1, wherein the sintering is performed in a closed environment, the sintering temperature is 450-530 ℃, and the sintering time is 25-35 min.

Technical Field

The invention belongs to the technical field of foam alloy manufacturing, and particularly relates to a preparation method of a biological foam magnesium alloy.

Background

The porous foam magnesium alloy is a novel structural functional material developed in recent years, has a series of unique mechanical, thermal, electrical and acoustic properties due to small density and large specific strength, can be widely applied to the building, ship, aviation and automobile manufacturing industries and packaging industries, and has attracted great interest in academic and industrial fields, such as functional structural materials for buildings, filling materials for automobile shock-proof boxes and doors, valuable instrument packaging materials, safety protection materials for lifting mechanisms, aircraft sandwich materials, sound-insulation and noise-reduction materials, electromagnetic shielding materials and the like. Particularly, with the improvement of the living standard of people and the aggravation of the aging of population at present, the requirement on the degradable biological material is higher and higher. Since the foam magnesium alloy gold has similar density and elastic modulus with human bone, good biocompatibility, and the advantages of biodegradation and drug portability, the research on the biological foam magnesium alloy is urgent.

At present, the method for preparing the porous foam magnesium alloy mainly comprises the following steps: one is a melt foaming method, namely, a foaming agent is added into a magnesium alloy melt, and the foaming agent is decomposed at a certain temperature to form holes, so that a closed-cell material is mainly prepared; the method for preparing magnesium alloy by directly foaming melt as disclosed in CN1966748 and the method for preparing foamed magnesium by foaming melt as disclosed in CN101135015 belong to the melt foaming method. However, the method has the defects of difficult control of foam pores, complex process of the casting process of the smelting liquid and higher cost. Another type is open-celled materials obtained by infiltration casting, i.e. infiltration of a metal melt into a preform. For example, a method for preparing foam magnesium alloy disclosed in CN101220424 and a preparation process of foam magnesium disclosed in CN 1544671. The method has the advantages of easy occurrence of explosion danger in the manufacturing process, higher cost, large operation difficulty, more product defects such as insufficient seepage, seepage flow passing and the like. Finally, a powder sintering method is a new process for preparing foam magnesium, and the method is characterized in that a pore-forming agent is added into magnesium alloy powder, and the magnesium alloy powder is mixed, then cold-pressed and sintered, and finally the pore-forming agent is heated, decomposed or dissolved subsequently. For example, CN103862051A discloses a method for preparing foamed magnesium for use in a cushioning energy-absorbing material. However, in the sintering process, the prepared porous foam magnesium alloy cannot be used for biological materials due to the complex thermal decomposition product of urea and difficult temperature control.

Therefore, various problems exist in the preparation of the biological foam magnesium alloy, and the development of a novel pore-forming agent and a corresponding preparation method are urgently needed, so that the defects existing in the preparation process of the existing foam magnesium alloy are overcome, and the biological foam magnesium alloy with uniform pore distribution, controllable pore size and good comprehensive performance is obtained.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a preparation method of a biological foam magnesium alloy.

In order to achieve the purpose, the invention provides the following technical scheme:

a preparation method of a biological foam magnesium alloy comprises the following steps:

and drying the zinc carbonate, the calcium carbonate spherulites and the magnesium alloy powder, mixing, cold pressing and sintering to obtain the foam magnesium alloy.

Further, the magnesium content of the magnesium alloy powder is more than or equal to 75 wt%.

Further, the particle size of the magnesium alloy powder is more than or equal to 80 meshes.

Further, the zinc carbonate and calcium carbonate spherulites take zinc carbonate coarse powder and calcium carbonate coarse powder as cores and zinc carbonate fine powder and calcium carbonate fine powder as shells;

the particle sizes of the zinc carbonate coarse powder and the calcium carbonate coarse powder are both larger than 100 meshes and smaller than 140 meshes; the granularity of the zinc carbonate fine powder and the calcium carbonate fine powder is more than or equal to 140 meshes.

Further, the preparation method of the zinc carbonate and calcium carbonate spherulites comprises the following steps: mixing zinc carbonate coarse powder and calcium carbonate coarse powder to obtain a mixture A; mixing the zinc carbonate fine powder and the calcium carbonate fine powder to obtain a mixture B; kneading 62-80 wt% of the mixture A and 20-38 wt% of a polyvinyl alcohol aqueous solution, and extruding by using an extruder to obtain particles; the granules were then placed in mixture B and rolled to give pellets.

Further, the concentration of the polyvinyl alcohol aqueous solution was 5 wt%.

Furthermore, the particle sizes of the zinc carbonate pellets and the calcium carbonate pellets are both 1-3 mm.

Furthermore, the mass ratio of the zinc carbonate and calcium carbonate spherulites to the magnesium alloy powder is 1: 8-10, and the mass ratio of the zinc carbonate and the calcium carbonate in the zinc carbonate and calcium carbonate spherulites is 3-5: 1.

By adopting a series of magnesium salt mixtures with different particle sizes and volume ratios, the spatial distribution of holes and porosity can be regulated and controlled, and the biological foam material with uniformly distributed holes and uniform density is manufactured; the porosity can be precisely controlled by adjusting the volume ratio of the magnesium alloy powder to the foaming agent.

Further, the cold pressing is carried out at room temperature, the pressure is 40MPa, and the pressure maintaining time is 3-4 min.

Further, the sintering is carried out in a closed environment, the sintering temperature is 450-530 ℃, and the sintering time is 25-35 min.

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

(1) the magnesium alloy powder, the zinc carbonate and the calcium carbonate spherulites are dried before cold pressing, so that the oxidation in the processing process is reduced; the sintering by using the powder metallurgy method avoids the difficulty of smelting, simplifies the production process, reduces the production cost and is suitable for large-scale industrial production.

(2) The foaming agent adopts spherulite zinc carbonate and calcium carbonate with a core-shell structure formed by coarse powder and fine powder, so that the problem of uneven hole distribution is solved, and the problem of corrosivity caused by excessive use of calcium carbonate is also solved.

(3) The preparation method can obtain the foam magnesium alloy with uniform holes, has proper porosity, uniform pore size distribution, consistent hole wall thickness, excellent performance and good application prospect.

(4) The foam magnesium alloy prepared by the invention contains Mg, Zn and Ca which are beneficial to human bodies, and the obtained material has excellent performance, meets the application requirements of biological materials, and is a biological foam magnesium alloy with good application prospect.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The description and examples are intended to be illustrative only.

In the following examples, the magnesium content of the magnesium alloy powder used was 85 wt%;

the granularity of the used zinc carbonate coarse powder and calcium carbonate coarse powder is larger than 100 meshes and smaller than 140 meshes; the granularity of the used zinc carbonate fine powder and calcium carbonate fine powder is more than or equal to 140 meshes;

the coarse powder with the granularity of more than 100 meshes and less than 140 meshes is salt powder which can pass through a 100-mesh Taylor standard sieve and can not pass through a 140-mesh Taylor standard sieve and is remained in the 140-mesh Taylor standard sieve; the fine powder with the granularity of more than or equal to 140 meshes is salt powder passing through a Taylor standard sieve with 140 meshes;

the description will not be repeated below.

Example 1

The preparation of the biological foam magnesium alloy comprises the following steps:

(1) uniformly mixing zinc carbonate coarse powder and calcium carbonate coarse powder in a mass ratio of 3: 1 to obtain a mixture A; uniformly mixing zinc carbonate fine powder and calcium carbonate fine powder in a mass ratio of 3: 1 to obtain a mixture B; putting a 62 wt% mixture A and a 38 wt% polyvinyl alcohol aqueous solution into a kneader for kneading, wherein the concentration of the polyvinyl alcohol aqueous solution is 5 wt%, putting the kneaded mixture C into a plastic container for standing for 24 hours, putting the mixture C into an extruder for extruding at room temperature, the extruding speed is 0.3m/min, obtaining particles with the particle size of about 1mm, directly putting the particles obtained by extruding into a mixture B, rolling the particles into round balls with the diameter of 1-3 mm, and drying the round balls for 20min at 100 ℃;

(2) respectively placing 100 meshes of magnesium alloy powder and the balls obtained in the step (1) in a drying oven at 120 ℃, drying for 10min, weighing the magnesium alloy powder and the balls according to the mass ratio of the balls to the magnesium alloy powder of 1: 9, and uniformly mixing;

fully and uniformly mixing the magnesium alloy powder and the round balls in the powder mixing stage;

(3) placing the mixture obtained in the step (2) on a 50-ton press, cold pressing at room temperature, using vaseline as a lubricant during extrusion, wherein the extrusion speed is 1mm/s, the pressure is 40MPa, and keeping the pressure for 3 min;

(4) and (4) placing the precast block obtained by cold pressing in the step (3) in a closed stainless steel container, filling and compacting with an asbestos mesh, sintering at the temperature of 450 ℃ for 30min, and then cooling along with a furnace to obtain the biological foam magnesium alloy.

Example 2

Preparing a biological foam magnesium alloy:

(1) uniformly mixing zinc carbonate coarse powder and calcium carbonate coarse powder in a mass ratio of 4: 1 to obtain a mixture A; uniformly mixing zinc carbonate fine powder and calcium carbonate fine powder in a mass ratio of 4: 1 to obtain a mixture B; putting 80 wt% of mixture A and 20 wt% of polyvinyl alcohol aqueous solution into a kneader for kneading, wherein the concentration of the polyvinyl alcohol aqueous solution is 5 wt%, putting the kneaded mixture C into a plastic container for standing for 20 hours, putting the mixture C into an extruder for extruding at room temperature, the extruding speed is 0.5m/min, obtaining particles with the particle size of about 1mm, directly putting the particles obtained by extruding into the mixture B, rolling the particles into round balls with the diameter of 1-3 mm, and drying the round balls for 20min at 100 ℃;

(2) respectively placing 80-mesh magnesium alloy powder and the balls obtained in the step (1) in a drying oven at 120 ℃, drying for 5min, weighing the magnesium alloy powder and the balls according to the mass ratio of the balls to the magnesium alloy powder of 1: 8, and uniformly mixing;

(3) placing the mixture obtained in the step (2) on a 50-ton press, cold pressing at room temperature, using vaseline as a lubricant during extrusion, wherein the extrusion speed is 2mm/s, the pressure is 40MPa, and keeping the pressure for 4 min;

(4) and (4) placing the precast block obtained by cold pressing in the step (3) in a closed stainless steel container, filling and compacting with an asbestos mesh, sintering at 500 ℃ for 30min, and cooling along with a furnace to obtain the biological foam magnesium alloy.

Example 3

The preparation of the biological foam magnesium alloy comprises the following steps:

(1) uniformly mixing zinc carbonate coarse powder and calcium carbonate coarse powder in a mass ratio of 5: 1 to obtain a mixture A; uniformly mixing zinc carbonate fine powder and calcium carbonate fine powder in a mass ratio of 5: 1 to obtain a mixture B; putting 70 wt% of the mixture A and 30 wt% of polyvinyl alcohol aqueous solution into a kneader for kneading, wherein the concentration of the polyvinyl alcohol aqueous solution is 5 wt%, putting the kneaded mixture C into a plastic container for standing for 12 hours, putting the mixture C into an extruder for extruding at room temperature, the extruding speed is 0.4m/min, obtaining particles with the particle size of about 1mm, directly putting the particles obtained by extruding into the mixture B, rolling into round balls with the diameter of 1-3 mm, and drying the round balls for 20min at 100 ℃;

(2) respectively placing 120-mesh magnesium alloy powder and the balls obtained in the step (1) in a drying oven at 120 ℃, drying for 10min, weighing the magnesium alloy powder and the balls according to the mass ratio of the balls to the magnesium alloy powder of 1: 10, and uniformly mixing;

(3) placing the mixture obtained in the step (2) on a 50-ton press, cold pressing at room temperature, using vaseline as a lubricant during extrusion, wherein the extrusion speed is 1.5mm/s, the pressure is 40MPa, and keeping the pressure for 3.5 min;

(4) and (4) placing the precast block obtained by cold pressing in the step (3) in a closed stainless steel container, filling and compacting with an asbestos mesh, sintering at 530 ℃ for 30min, and cooling along with a furnace to obtain the biological foam magnesium alloy.

Comparative example 1

The difference from example 1 is that step (2) is: weighing 100 meshes of magnesium alloy powder and the balls obtained in the step (1) according to the mass ratio of the balls to the magnesium alloy powder of 1: 9, and uniformly mixing.

Comparative example 2

The same as example 1 except that in the step (1), only calcium carbonate coarse powder and fine powder were used, and zinc carbonate coarse powder and zinc carbonate fine powder were not added; and the dosage of the calcium carbonate coarse powder is the sum of the dosages of the calcium carbonate coarse powder and the zinc carbonate coarse powder in the step (1), and the dosage of the calcium carbonate fine powder is the sum of the dosages of the calcium carbonate fine powder and the zinc carbonate fine powder in the step (1).

Comparative example 3

The difference from example 1 is that, in step (1), mixture B was obtained by uniformly mixing zinc carbonate coarse powder and calcium carbonate coarse powder at a mass ratio of 3: 1.

Comparative example 4

The difference from example 1 is that, in step (1), mixture A was obtained by uniformly mixing zinc carbonate fine powder and calcium carbonate fine powder at a mass ratio of 3: 1.

Effect verification

1. The pore size range and porosity of the bio-foam magnesium alloys prepared in examples 1 to 3 and comparative examples 1 to 4 were measured, and the results are shown in table 1.

2. Detecting the compressive stress, the corrosion resistance and the thermal diffusion coefficient of the biological foam magnesium alloy prepared in the embodiments 1-3 and the comparative examples 1-4, wherein the compressive stress detection is carried out at normal temperature, the compression rate is 1mm/min, and the compressive stress when the strain reaches 50% is recorded; the corrosion resistance test adopts a soaking experiment method: soaking the biological foam magnesium alloy in 3 wt% NaCl solution, cleaning and drying with dilute nitric acid before soaking, taking out after soaking for 6h, 12h and 24h respectively, cleaning with dilute nitric acid, removing corrosive substances on the surface, weighing after drying, and calculating the weight loss ratio by adopting the following formula:

wherein M is₀The initial mass before soaking of the foamed magnesium alloy, M_XIs the mass after soaking for x hours.

The results of the compressive stress and thermal diffusion coefficient measurements are shown in table 1; the weight loss ratio is shown in table 2.

TABLE 1

Group of	Pore size range/. mu.m	Porosity/%	Compressive stress/MPa	Thermal diffusivity per meter2/s
					Example 1	290～410	75	51	21.2
Example 2	315～380	72	53	22.3
					Example 3	305～415	76.3	51	19.5
Comparative example 1	245～435	70	50	26.8
					Comparative example 2	285～423	78	42	19.2
Comparative example 3	275～432	62	52	36.6
					Comparative example 4	270～484	68	50	30.5

TABLE 2

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be able to cover the technical solutions and the inventive concepts of the present invention within the technical scope of the present invention.