CN113388792B - A kind of biomedical amorphous magnesium alloy powder, composite material and preparation process - Google Patents

Abstract

The invention provides a biomedical amorphous magnesium alloy powder, a composite material and a preparation process, and relates to the technical field of biomedical magnesium alloys. The amorphous magnesium alloy powder is composed of the following components in atomic percentage: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%. A biomedical amorphous magnesium alloy composite material is prepared from the aforementioned biomedical amorphous magnesium alloy powder as a raw material powder. The biomedical amorphous magnesium alloy powder provided by the present application can prepare an amorphous magnesium alloy composite material by a selective laser melting process (SLM). While retaining the amorphous structure of the amorphous magnesium alloy powder, According to actual needs, large-sized and complex-shaped bulk amorphous magnesium alloys are prepared.

Description

A kind of biomedical amorphous magnesium alloy powder, composite material and preparation process

technical field

The invention relates to the technical field of biomedical magnesium alloys, in particular to a biomedical magnesium alloy composite material and a preparation process.

Background technique

Mg is one of the constant elements constituting the essential elements of the human body, and ranks fourth as a metal element after Ca, K, and Na. Mg and its alloys have the characteristics of low density, high specific strength and low elastic modulus. At the same time, Mg is prone to corrosion and degradation in various body fluid environments, achieving the medical and clinical purpose of metal implants gradually degrading in the body and eventually disappearing. Therefore, the attractive potential of Mg and its alloys as a biodegradable biomedical implant material for orthopaedic applications has attracted more and more attention. When it is implanted into the human body, it will not cause an acute reaction, nor will there be an obvious reaction during the implantation process, and the degradation of Mg and its alloys can also stimulate and promote bone healing.

However, the standard electrode potential of Mg is very low, about -2.37 V (vs SCE), which makes Mg and its alloys have poor corrosion resistance and rapid degradation. It is usually less than the time required for bone tissue healing (more than 12 weeks), and at the same time, the release of excessive _H2 during its degradation will form air pockets under the skin, which will hinder the interaction between the implant and bone tissue to a certain extent, affecting the bone tissue healing. Especially in Mg alloys, alloying elements and Mg form precipitates and form galvanic corrosion with Mg matrix, which accelerates the corrosion rate of Mg alloys. At the same time, the pitting corrosion caused by surface defects will also lead to the decline of the mechanical properties of Mg alloys.

In contrast, magnesium-based amorphous alloys have a large number of holes due to the irregular arrangement of atoms, and the atomic distribution is uniform and single-phase, and there is no grain boundary, which reduces defects, thereby improving the corrosion resistance and corrosion resistance of the material. mechanical properties. However, since amorphous alloys are formed by the rapid solidification of metal melts, there is a technical bottleneck in the fabrication of large-scale and complex structural parts during the forming process. In recent years, the manufacture of bulk amorphous bio-magnesium alloys mainly adopts copper mold casting and thermoplastic forming. The copper mold casting method is to inject the magnesium alloy melt into the copper mold cavity to realize the direct forming of the bulk amorphous magnesium alloy. For example, Liquidmetal has successfully achieved the preparation of the bulk amorphous magnesium alloy by using the die casting technology. However, the fast cooling rate of the copper mold seriously affects the fluidity of the alloy melt, which brings challenges to the fabrication of complex parts. The thermoplastic forming method mainly uses the superplasticity of amorphous alloys in the supercooled liquid region, and adopts forming technologies such as imprinting, injection molding, blow molding, and extrusion to achieve near-net forming of nano-to-centimeter-scale parts, but this method is only suitable for micro The imprint forming of parts is difficult to form large-sized and complex structural parts.

SUMMARY OF THE INVENTION

In order to realize the bulk amorphous magnesium alloy with large size and complex shape, the present invention provides a biomedical amorphous magnesium alloy powder, a composite material and a preparation process.

A biomedical amorphous magnesium alloy powder provided by the application adopts the following technical scheme:

The amorphous magnesium alloy powder is composed of the following components in atomic percentage: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%.

By using the above alloy composition range, amorphous magnesium alloy powder can be prepared, and 3D printing technology, such as selective laser melting process (SLM), can be used to prepare amorphous magnesium alloy composite material, while retaining the amorphous state At the same time of the amorphous structure of the magnesium alloy powder, the amorphous magnesium alloy with large size and complex shape is prepared according to the actual demand.

Preferably, the amorphous magnesium alloy powder is spherical powder, and the particle size of the powder is 15-105 μm.

By using the above technical scheme, the good fluidity of spherical powder is used to improve the uniformity of powder spreading during the laser melting process, so as to ensure the uniformity of the internal structure of the final prepared amorphous magnesium alloy composite material, while the particle size of the powder is improved. The range is 15-105μm, which is easier for powder flow and laser melting molding.

Preferably, the amorphous magnesium alloy powder is spherical powder, and the particle size of the powder is 15-75 μm.

By adopting the above technical scheme, the amorphous magnesium alloy powder with a powder particle size of 15-75 μm is selected as the raw material, and the amorphous magnesium alloy composite material is prepared by the laser melting process, and the amorphous structure of the powder is preferably preserved. At the same time, the number of crystalline phases is small, the degradation rate is low, and the anti-corrosion degradation performance is excellent.

The present application provides a preparation process of biomedical amorphous magnesium alloy powder, comprising the following steps:

S1. Raw materials are batched by atomic percentage: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%;

S2. Smelting the prepared raw materials to prepare the target master alloy;

S3. Atomizing and pulverizing the target master alloy to obtain an amorphous magnesium alloy powder.

By adopting the above technical scheme, amorphous magnesium alloy powder can be prepared, the process is simple, the operation is easy, and it is suitable for industrial application and popularization.

Preferably, the smelting temperature in step S2 is 720°C to 750°C.

By adopting the above technical solution, the raw materials can be fully melted, and at the same time, the loss of raw materials can be avoided, and the target alloy of the target composition can be obtained.

Preferably, the air pressure of the atomized powder in step S3 is 1.8-2.2 MPa, and the air velocity is 300-340 m/s.

By adopting the above technical solution, spherical powder with a target particle size can be obtained, and the spherical powder has a uniform particle size, thereby improving the fluidity and uniformity of powder spreading in the subsequent laser melting process.

The present application provides a biomedical amorphous magnesium alloy composite material, which is prepared from the aforementioned biomedical amorphous magnesium alloy powder as a raw material powder. The phase structure of the amorphous magnesium alloy composite material includes an amorphous phase and any The selected crystal phase, the optional crystal phase is the Mg phase, or the optional crystal phase is the Mg phase, the Ca ₂ Mg ₅ Zn ₁₃ phase, and the Ca ₂ Mg ₆ Zn ₃ phase.

By adopting the above technical solution, the corrosion resistance and mechanical properties of magnesium alloys can be improved. Magnesium-based amorphous alloys have a large number of holes due to the irregular arrangement of atoms, and the atomic distribution is uniform and single-phase, and there is no grain boundary. Defects are reduced, thereby improving the corrosion resistance and mechanical properties of the material.

Preferably, the phase structure of the amorphous magnesium alloy composite material includes an amorphous phase and a Mg phase, and the Mg phase is an α-Mg microcrystalline structure, and the volume ratio of the α-Mg microcrystalline structure to the composite material is 15 %.

By adopting the above technical solution, the _crystalline phase _includes the _{Mg phase} , which _reduces the crystalline phase composition of the amorphous magnesium alloy composite material, thereby improving the ₃ phases, and the potential difference between them and the amorphous structure causes galvanic corrosion, and the α-Mg microcrystalline structure has good plasticity, which further improves the mechanical properties of the amorphous magnesium alloy composites.

The present application provides a process for preparing a biomedical amorphous magnesium alloy composite material, which is prepared by using the aforementioned biomedical amorphous magnesium alloy powder as a raw material and a selective laser melting process.

By adopting the above technical scheme, large-sized and complex-shaped bulk amorphous magnesium alloys can be conveniently prepared according to actual requirements, without being restricted by casting and thermoplastic forming, the process is simple, and it is easy for industrial application and popularization.

Preferably, the parameters of the selective laser melting process are: the laser spot is 70 μm, the laser scanning speed is 80-100 mm/s, the laser power is 80-110 W, the scanning times are 1-3 times, and the scanning spacing is 0.06-0.08 mm.

By adopting the above technical scheme, an amorphous magnesium alloy composite material can be prepared, the amorphous structure of the raw material amorphous powder can be better retained, and the corrosion resistance and mechanical properties of the amorphous magnesium alloy material can be improved.

To sum up, the present application includes at least one of the following beneficial technical effects:

1. A kind of biomedical amorphous magnesium alloy powder provided by this application can prepare amorphous magnesium alloy powder, and can use 3D printing technology, such as selective laser melting process (SLM), to prepare amorphous magnesium alloy powder For the magnesium alloy composite material, while retaining the amorphous structure of the amorphous magnesium alloy powder, the amorphous magnesium alloy with large size and complex shape can be prepared according to actual needs.

2. The preparation process of the biomedical amorphous magnesium alloy powder provided by the present application can prepare the amorphous magnesium alloy powder, the process is simple, the operation is easy, and it is suitable for industrial application and promotion.

3. A biomedical amorphous magnesium alloy composite material provided by this application can improve the corrosion resistance and mechanical properties of magnesium alloys. The magnesium-based amorphous alloys have a large number of holes due to the irregular arrangement of atoms, and the atomic distribution is uniform. There is no grain boundary, which reduces defects, thereby improving the corrosion resistance and mechanical properties of the material.

4. The preparation process of a biomedical amorphous magnesium alloy composite material provided by this application can prepare an amorphous magnesium alloy composite material, which can better retain the amorphous structure of the raw material amorphous powder, and improve the performance of the amorphous magnesium alloy. Corrosion resistance and mechanical properties of materials.

Description of drawings

FIG. 1 is the XRD pattern of the target master alloy prepared in Example 1 of the application.

FIG. 2 is an optical microscopic image of the target master alloy prepared in Example 1 of the present application.

FIG. 3 is an SEM image of the amorphous magnesium alloy powder prepared in Example 1 of the application.

FIG. 4 is the XRD pattern of the amorphous magnesium alloy powder prepared in Example 1 of the application.

FIG. 5 is the XRD pattern of the amorphous magnesium alloy composite material prepared in Example 1 of the application.

FIG. 6 is an SEM image of the amorphous magnesium alloy powder prepared in Example 2 of the present application.

FIG. 7 is the XRD pattern of the amorphous magnesium alloy powder prepared in Example 2 of the application.

FIG. 8 is the XRD pattern of the amorphous magnesium alloy composite material prepared in Example 2 of the application.

FIG. 9 is the XRD pattern of the amorphous magnesium alloy powder prepared in Example 3 of the application.

FIG. 10 is the XRD pattern of the amorphous magnesium alloy composite material prepared in Example 3 of the application.

FIG. 11 is the XRD pattern of the amorphous magnesium alloy composite material prepared in Example 4 of the application.

FIG. 12 is an optical microscope image of the amorphous magnesium alloy composite material prepared in Example 4 of the application.

FIG. 13 is the XRD pattern of the amorphous magnesium alloy composite material prepared in Example 5 of the application.

FIG. 14 is the XRD pattern of the amorphous magnesium alloy composite material prepared in Example 6 of the application.

FIG. 15 is the XRD pattern of the amorphous magnesium alloy composite material prepared in Example 7 of the application.

Detailed ways

At present, common biomedical magnesium alloys mainly include Mg-Ca, Mg-Zn, Mg-Mn, Mg-Sr and Mg-RE alloys. These alloyed alloys have good biocompatibility and have no adverse effects on the structure. . Among them, Mg-Zn-Ca alloys are currently a research hotspot in the field of medical alloys due to their high specific strength and specific stiffness, elastic modulus similar to that of human bones, and good biocompatibility. However, since the ability of magnesium alloy to form amorphous structure is affected by the alloy system, for Mg-Zn-Ca alloy, it belongs to the alloy system with weaker ability to form amorphous structure. In order to obtain the amorphous structure of the Mg-Zn-Ca alloy, the patent document with the authorization announcement number CN109161766B discloses a biological magnesium alloy containing an amorphous fused layer and a preparation method thereof. The amorphous fused layer is obtained by the laser melting process. Using the fiber laser, the energy density is high, the spot is small, the forming precision is high, especially the cooling rate is fast. The temperature causes it to melt, and then the molten metal surface is rapidly quenched and solidified by the endothermic and conduction heat effects of the cooler metal matrix, thereby forming an amorphous layer.

However, for large-sized and complex-shaped bulk amorphous magnesium alloys, the ability to conduct heat in different parts of the bulk is different, and it cannot guarantee the formation of an amorphous layer of uniform thickness on the surface of the bulk. After the corrosion breakdown of the layer occurs, it will lead to accelerated corrosion degradation of the entire block.

In order to achieve large-scale, complex-shaped bulk amorphous magnesium alloys, the present application provides an amorphous magnesium alloy powder, a selective laser melting process in 3D printing technology, using a CO ₂ laser to pass highly complex parts through Layer-by-layer printing can achieve great design freedom without any mold, breaking through the limitation of amorphous Mg-Zn-Ca alloy formation ability, thereby realizing the preparation of large-sized and complex-shaped bulk amorphous alloy parts.

Hereinafter, the amorphous magnesium alloy powder, the amorphous magnesium alloy composite material and the preparation process of the present application will be described in detail.

1. Amorphous magnesium alloy powder

The amorphous magnesium alloy powder of the present application is a magnesium alloy powder having an amorphous structure. This application mainly takes the Mg-Zn-Ca alloy system as an example to study the influence of amorphous magnesium alloy powder and amorphous magnesium alloy powder on the preparation of amorphous magnesium alloy composite materials or devices. The amorphous magnesium alloy powder is composed of the following components in atomic percentage: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%. It may also be: Mg: 55 to 65 at.%; Zn: 30 to 35 at.%; Ca: the remainder, and the sum of the alloy components is 100 at.%. Amorphous magnesium alloy powders can also cover other magnesium alloy systems.

The amorphous magnesium alloy powder of the present application is used to prepare amorphous magnesium alloy composite materials or devices, etc., 3D printing molding, powder sintering molding, powder injection molding, hot isostatic pressing molding and other processes can be used. Take laser melting as an example to prepare amorphous magnesium alloy composites.

For the amorphous magnesium alloy powder of the present application, the target mother alloy is heated to melting in an atomization device, and the superheat is maintained at 100-150°C, and a metal liquid flow with a diameter of 5-6mm is formed; The pressure is 1.8-2.2MPa, and the air velocity is 300-340m/s, that is, amorphous magnesium alloy powder is obtained. The prepared powder is spherical powder, the diameter of the powder is 15-105 μm, can be 15-45 μm, can be 45-53 μm, can be 15-75 μm, can be 75-105 μm, preferably 15-75 μm. The sphericity is high, the fluidity is good, and the powder spreading uniformity is good. Suitable for 3D laser printing. The atomization process is in an anaerobic and closed-loop device environment to prevent the powder from being oxidized during the preparation process. During the condensation process, the liquid alloy is atomized into amorphous spherical powder with high circularity. The alloy material has excellent flame retardant performance, and the powder particle size is easy to control, which solves the problem of flammability of magnesium alloy powder prepared by atomization.

For the smelting and preparation of the target master alloy, firstly, the raw materials are batched according to the alloy with the following design composition: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%. It may also be: Mg: 55 to 65 at.%; Zn: 30 to 35 at.%; Ca: the remainder, and the sum of the alloy components is 100 at.%. The composition of Mg in the raw material can be 57%, 58～60at.%, 62%, 63～65at.%, the composition of Zn can be 30～32at.%; 33at.%, 34～35at.%, the balance Ca , the total amount of alloy components is 100at.%. After pretreatment to remove surface oxides, smelting is carried out in a protective atmosphere at a smelting temperature of 720°C to 750°C. The alloy is fully melted to form a magnesium alloy melt, which is poured into a preheated metal mold to obtain the target master alloy.

2. Amorphous magnesium alloy composites

The amorphous magnesium alloy composite material of the present application is prepared by using the biomedical amorphous magnesium alloy powder prepared by the gas atomization method as the raw material powder, and using a high-energy CO ₂ laser beam to selectively melt the amorphous alloy powder. The three-dimensional solid model is constructed by computer, and the layered model generated along the Z direction and the scanning path program of each layer are set, and the thickness of each layer is 0.5-1mm. After the laser scan is complete, the work plane is lowered, the next layer of metal powder is deposited on its top surface, and the new layer is laser scanned. Repeat the above process, and finally print the required parts. The laser scanning process parameters are as follows: the laser spot is 70μm; the laser scanning speed is 80~100mm/s, which can be 80mm/s, 85mm/s, 90mm/s, 95mm/s, 100mm/s; the laser power is 80~110W , can be 80W, 85W, 90W, 95W, 100W, 105W, 110W; scan times are 1 to 3 times, can be 1 time, 2 times, 3 times; scan spacing is 0.06 to 0.08mm, can be 0.06mm, 0.07 mm, 0.08mm.

The following detailed description is given in conjunction with the embodiments.

Example 1

The pure magnesium ingot, pure zinc ingot and magnesium-calcium 30 master alloy ingot are batched according to the composition of the target master alloy. The composition of the target master alloy is: Mg: 60at.%; Zn: 35at.%; Ca: 5at.%, The surface of the metal raw material is ground to remove oxides on the surface of the metal raw material, and then placed in an oven and dried at 110° C. for 2 hours.

Under the protection of the mixed atmosphere of CO ₂ and SF ₆ , the flow rate of CO ₂ gas was set to 10ml/min, and the flow rate of SF ₆ gas was set to 40ml/min, and the magnesium ingot was melted in a resistance furnace, and the melting temperature was set to 720 ℃, after the magnesium ingot is completely melted and kept for 10 minutes, the preheated pure zinc ingot and magnesium-calcium 30 master alloy ingot are added to the magnesium melt. After the pure zinc ingots and magnesium-calcium 30 master alloy ingots to be added are fully melted, they are stirred for another 2 minutes to ensure adequate mixing of alloying elements. Then, it was left to stand for 20 minutes, the slag was skimming, and the alloy liquid was poured into a preheated metal mold to obtain the target master alloy. The XRD pattern of the target master alloy is shown in Figure 1. It can be seen from the XRD pattern that there are characteristic peaks of multiple phases in the target master alloy after smelting. The master alloy includes Mg phase, Ca ₂ Mg ₅ Zn ₁₃ , Mg ₂ Zn ₁₁ , Ca ₂ Mg ₆ Zn ₃ , MgZn ₂ . Figure 2 shows the optical morphology of the target master alloy. It can be seen from Figure 2 that the α-Mg matrix contains a large number of light white bulk CaMgZn phases and gray needle-shaped MgZn phases.

Put the target mother alloy into the atomization equipment, heat the target mother alloy to melt, keep the superheat at 150 ° C, and form a metal liquid flow with a diameter of 5-6 mm; pass argon gas through an annular nozzle, the gas flow pressure is 2.0 MPa, and the gas flow When the speed is 320m/s, magnesium alloy powder is obtained. The diameter of the prepared amorphous magnesium alloy powder is 15-75 μm, as shown in Figure 3, which is the SEM morphology of the magnesium alloy powder prepared by the gas atomization method used in Example 1. It can be seen from Figure 3 that the magnesium alloy The alloy powder is spherical powder with high sphericity, and the number of symbiotic satellite spherical powder is also small.

Fig. 4 is the XRD pattern of the magnesium alloy powder prepared in Example 1 of the application. It can be seen from Fig. 4 that, compared with the XRD pattern of the target master alloy cast in Fig. 1, the crystalline phase in the phase structure of the magnesium alloy powder : Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase, Ca ₂ Mg ₆ Zn ₃ phase, Mg ₂ Zn ₁₁ phase, and MgZn ₂ phase disappear, and broadened diffraction peaks appear, which are obvious amorphous features, so , the magnesium alloy powder prepared in Example 1 is an amorphous magnesium alloy powder.

Taking the amorphous magnesium alloy powder prepared in Example 1 as the original powder, a high-energy laser beam was used to selectively melt the amorphous magnesium alloy powder, and the magnesium alloy powder was scanned layer by layer. Lower the printing work plane, lay the next layer of magnesium alloy powder on the top surface, and then laser scan the new layer. The above process is repeated in this way, and the required parts are finally printed. The laser adopts CO ₂ laser, the laser spot is 70μm, the scanning distance is 0.07mm, the laser power is 110W, the laser scanning speed is 100mm/s, and the powder thickness of each layer is about 0.5mm. 5 is the XRD diffraction pattern of the magnesium alloy composite material prepared by selective laser melting of amorphous magnesium alloy powder in Example 1. As can be seen from Fig. 5, compared with the XRD patterns of Fig. 1 and Fig. 4, in addition to the amorphous phase, the magnesium alloy composite also contains crystalline phases: Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase. The amorphous magnesium alloy composite material prepared in Example 1 was subjected to an immersion experiment to collect the released volume of gas, and the degradation rate of the amorphous alloy was calculated according to the hydrogen evolution rate (Song GL, Atrens A, Stjohn D. An hydrogenevolution method for the estimation of the corrosion rate of magnesiumalloys. Magnes. Technol. (Ed. Hryn JN, TMS) 2001; 255-262.), its degradation rate was obtained as 0.61 mm/y (mm/year).

Example 2

The difference between Example 2 and Example 1 is that in the gas atomization powdering step of the target mother alloy, the air pressure is 1.8 MPa, the air velocity is 300 m/s, and the obtained magnesium alloy powder has a diameter of 75-105 μm. FIG. 6 shows the SEM morphology of the magnesium alloy powder prepared in Example 2. It can be seen from Figure 6 that the magnesium alloy powder prepared in Example 2 is spherical powder with higher sphericity. Compared with the powder obtained in Example 1, the particle size distribution is narrower and the number of symbiotic satellite spheres increases. FIG. 7 is the XRD pattern of the magnesium alloy powder prepared in Example 2 of the application, and still obtains obvious broadened diffraction peaks, indicating that the obtained powder is also an amorphous magnesium alloy powder.

FIG. 8 is the XRD diffraction pattern of the magnesium alloy composite material prepared in Example 2. FIG. It can be seen from Fig. 8 that the alloy contains Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase in addition to the amorphous phase. Compared with the XRD pattern of Example 1, the aforementioned crystalline phase The peak intensity of the characteristic increased significantly, indicating that the proportion of crystalline phase increased. The main reason for the analysis is that the particle size of the amorphous magnesium alloy powder used in the laser melting process is larger than that in Example 1, so that during the laser melting process, the amorphous magnesium alloy powder cannot be completely melted and is subject to heat transfer. The effect of nucleation of atoms makes it easier for atoms to nucleate, resulting in an increase in the crystalline phase. The degradation rate of the tested bulk alloy is 0.94mm/y (mm/year), and the reason for the obvious increase in the degradation rate is that the particle size of the powder is too large and the particle size distribution is narrower. Poor binding and the presence of microvoids further accelerate degradation.

Example 3

The difference between Example 3 and Example 1 is that in the step of atomizing and powdering the mother alloy ingot, the air pressure is 2.2 MPa, the air velocity is 340 m/s, and the obtained magnesium alloy powder has a diameter of 15-45 μm. FIG. 9 is the XRD pattern of the magnesium alloy powder prepared in Example 3. It can be seen from FIG. 9 that the magnesium alloy powder is still an amorphous powder. The morphology of the magnesium alloy powder was detected, and it was found that the amorphous magnesium alloy powder was also spherical powder, with high sphericity, and the number of symbiotic satellite spheres was reduced.

FIG. 10 is the XRD pattern of the magnesium alloy composite material prepared in Example 3. FIG. It can be seen from Figure 10 that the Mg phase, the Ca ₂ Mg ₅ Zn ₁₃ phase and the Ca ₂ Mg ₆ Zn ₃ phase crystallographic phase still appear. It is worth mentioning that, compared with Example 1, Example 3 The amorphous diffraction peaks are significantly broadened, indicating that the amorphous structure is more pronounced. The main reason for the analysis is that the particle size of the amorphous magnesium alloy powder used in the laser melting process is smaller than that in Example 1, so that during the laser melting process, the melting speed of the amorphous powder becomes faster and the crystallization speed is suppressed. , more amorphous structure is preserved. However, due to the further reduction of powder particle size, the magnesium element is easily burnt out during the laser melting process, and the crystallinity of impurities such as Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase increases correspondingly. The degradation rate of the magnesium alloy composite material in Test Example 3 was 0.76 mm/y (mm/year).

Example 4

The difference between Example 4 and Example 1 is that in the laser melting process, the laser power is 90W.

FIG. 11 is the XRD diffraction pattern of the magnesium alloy composite material prepared in Example 4. FIG. It can be seen from FIG. 11 that only the Mg phase appears in the crystalline phase. Compared with Example 1, the amorphous diffraction peak of Example 4 is significantly broadened, indicating that the amorphous structure is more obvious. The main reason for the analysis is that the power used in the laser melting process is smaller than that in Example 1, and the burning loss of magnesium is reduced, so that the burning of magnesium is more retained, and the crystalline phase only forms the Mg phase, not the Mg phase. Other crystalline phases are formed, and at the same time, the laser melting power is reduced, so that the crystallization rate is slowed down, and the amorphous state of the powder is largely preserved. The degradation rate of the tested amorphous magnesium alloy composites is 0.29mm/y (mm/year), and the reason for the obvious decrease in the degradation rate is that the crystalline phase in the amorphous bulk is significantly reduced, which reduces the difference between the crystalline phase and the amorphous phase. Galvanic corrosion, and at the same time, after the powder is prepared into a block, the amorphous phase is well preserved. Because the amorphous phase has more obvious corrosion resistance, the degradation rate of the block is further reduced.

12 is an optical microscopic image of the amorphous magnesium alloy composite material of Example 4. FIG. It is found from FIG. 12 that the microstructure of the amorphous magnesium alloy composite material includes an amorphous matrix and α-Mg crystallites distributed in the amorphous matrix, and the volume ratio of the α-Mg crystallites is 15%.

Example 5

The difference between Example 5 and Example 4 is that in the laser melting process, the laser power is 80W.

FIG. 13 is the XRD pattern of the amorphous magnesium alloy material prepared in Example 5. FIG. It can be seen from the XRD pattern that Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase crystallographic phase appeared in the alloy. Compared with Example 4, the crystal phase of Example 5 increases, mainly because the power used in the laser melting process is further reduced, and the amorphous powder is only partially melted. Due to the reason, the degradation rate of the tested bulk alloy is 0.68mm/y (mm/year).

Example 6

The difference between Example 6 and Example 4 is that in the laser melting process, the laser scanning speed is 80 mm/s.

FIG. 14 is the XRD pattern of the alloy bulk prepared in Example 6. FIG. As can be seen from Figure 14, Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase appeared in the crystal phase. Compared with Example 4, the crystal phase of Example 6 increased, mainly It is because the scanning speed used in the laser melting process becomes slower. With the decrease of scanning speed, the alloy gradually transforms from amorphous to crystalline state, and the Ca ₂ Mg ₅ Zn ₁₃ phase and the Ca ₂ Mg ₆ Zn ₃ phase in the alloy also change. gradually increase. The degradation rate of the test bulk alloy was 0.63 mm/y (mm/year).

Example 7

The difference between Example 7 and Example 4 is that in the laser melting process, the number of laser scans is 3 times.

FIG. 15 is the XRD diffraction pattern of the magnesium alloy composite material prepared in Example 7. FIG. It can be seen from Figure 15 that Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase appear in the crystal phase. Compared with Example 4, the crystal phase of Example 7 is increased, which is It is mainly 3-pass scanning, which makes the heat of the alloy accumulate and the crystallization phase increases. The degradation rate of the tested bulk alloy was 0.71 mm/y (mm/year).

Comparative Example 1

The difference from Example 1 is that the atomic ratio of magnesium, zinc, and calcium as the design components of the master alloy is 50:40:10. It can be seen from the XRD pattern of the powder prepared by atomization that in addition to the amorphous phase, the powder also has Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase crystalline phase. The corrosion rate of the magnesium alloy material prepared from the powder is 2.2 mm/y.

Comparative Example 2

The difference from Example 1 is that the atomic ratio of magnesium, zinc and calcium as the design components of the master alloy is 70:20:10. It can be seen from the XRD pattern of the powder prepared by atomization that in addition to a small amount of amorphous phase, a large amount of Mg phase, Ca ₂ Mg ₅ Zn ₁₃ phase and Ca ₂ Mg ₆ Zn ₃ phase crystal phase appear in the powder. , the corrosion rate of the magnesium alloy material prepared by the atomized powder is 3.6mm/y.

The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore: all equivalent changes made according to the mechanism, shape and principle of the present invention should be covered within the protection scope of the present invention. Inside.

Claims (5)

1. A biomedical amorphous magnesium alloy composite material is characterized in that: it is prepared by raw material powder from amorphous magnesium alloy powder, and described amorphous magnesium alloy powder is made up of the following atomic percentage components: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%, the amorphous magnesium alloy powder is prepared by a process comprising the following steps: S1. Raw materials are batched by atomic percentage: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%; S2. Smelting the prepared raw materials to prepare the target master alloy; S3. Atomizing and pulverizing the target master alloy to obtain an amorphous magnesium alloy powder; In step S3, the air pressure of atomization and powdering is 2.0MPa, and the air velocity is 320m/s; The amorphous magnesium alloy powder is spherical powder, the particle size of the powder is 15-75 μm, and the phase structure of the amorphous magnesium alloy composite material is an amorphous phase and a Mg phase. 2 . The biomedical amorphous magnesium alloy composite material according to claim 1 , wherein the Mg phase is an α-Mg microcrystalline structure, and the volume ratio of the α-Mg microcrystalline structure to the composite material is 15. 3 . %. 3 . The biomedical amorphous magnesium alloy composite material according to claim 1 , wherein the melting temperature in step S2 is 720° C.˜750° C. 4 . 4. A preparation process of a biomedical amorphous magnesium alloy composite material, characterized in that: using amorphous magnesium alloy powder as raw material powder to prepare the amorphous magnesium alloy composite material by a selective laser melting process, the amorphous magnesium alloy composite material is prepared. The alloy powder is composed of the following components in atomic percentage: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%, and the amorphous magnesium alloy powder is composed of a process comprising the following steps preparation: S1. Raw materials are batched by atomic percentage: Mg: 55-65 at.%; Zn: 30-35 at.%; Ca: 5-10 at.%; S2. Smelting the prepared raw materials to prepare the target master alloy; S3. Atomizing the target master alloy to powder to obtain amorphous magnesium alloy powder; In step S3, the air pressure of the atomization and pulverization is 2.0MPa, and the air velocity is 320m/s; The amorphous magnesium alloy powder is spherical powder, the particle size of the powder is 15-75 μm, and the phase structure of the prepared amorphous magnesium alloy composite material is amorphous phase and Mg phase. 5 . The preparation process of the biomedical amorphous magnesium alloy composite material according to claim 4 , wherein the parameters of the selective laser melting process are: the laser spot is 70 μm, the laser scanning speed is 100 mm/s, and the laser scanning speed is 100 mm/s. 6 . The power is 90W, the number of scans is 1, and the scan spacing is 0.07mm.

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