Molybdenum-rhenium alloy material implanted into human body and preparation method thereof

Abstract

The invention relates to a molybdenum-rhenium alloy material implanted into a human body and a preparation method of the molybdenum-rhenium alloy material, and aims to provide an implant material with high strength, high density and good biocompatibility. The material is composed of 45%-50% of rhenium, molybdenum and inevitable impurities, and through fiber strengthening and pressure processing, the tensile strength is larger than or equal to 1300 MPa, and the density is larger than or equal to 13.15 g / cm < 3 >. The preparation method comprises a powder metallurgy process and a vacuum electron beam melting process, and the deformation rate is larger than or equal to 65% through extrusion, forging, drawing or rolling. Experimental results show that the in-vitro cell survival rate of the material is higher than 90%, no obvious inflammatory reaction exists in vivo, fiber wrapping is thin, and tissue regeneration is good. Compared with existing stainless steel, magnesium alloy and titanium alloy, the molybdenum-rhenium alloy material has remarkable advantages in the aspects of strength, ductility and biocompatibility, and is suitable for surgical implantation application.

Description

Technical Field

[0001] The present invention belongs to the field of medical materials, and relates to a surgical implant material, and in particular to a molybdenum-rhenium alloy material for human body implantation. The present invention also relates to a preparation method of the molybdenum-rhenium alloy material. Background Art

[0002] In the field of surgical implant materials, widely used materials such as stainless steel, magnesium alloys and titanium alloys each have their own advantages and disadvantages. Stainless steel: low strength, resulting in larger implants, increased patient pain, not suitable for long-term use, and rich in Ni and Cr elements that are harmful to the human body, poor biocompatibility, prone to allergic and inflammatory reactions, and cannot be used for MRI examinations. Magnesium alloy: low strength, uneven corrosion problems, low density, and blurred edges during patient imaging. In addition, the corrosion products of magnesium alloys may have a negative impact on surrounding tissues. Titanium alloy: good biocompatibility, less human body rejection, good corrosion resistance, but still insufficient strength, low density, and blurred edges during patient imaging. Moreover, titanium alloys may exhibit a higher elastic modulus in some cases, which does not match the elastic modulus of bones and may lead to a stress shielding effect.

[0003] Existing research is also trying to improve the performance of these materials by adding other elements or changing the material structure, but often while improving one performance, it sacrifices the advantages of other aspects and still cannot completely solve all problems. For example, some studies have tried to add rare earth elements to titanium alloys to improve their strength and corrosion resistance, but these improvements often lead to a significant increase in material costs and may introduce other adverse biocompatibility issues. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a human implant material - molybdenum-rhenium alloy, which has good biocompatibility, good integration with human biological tissues, and almost no rejection or allergic reaction. The material is fiber-reinforced, with a grain aspect ratio greater than 4, high strength, excellent durability and ductility, and can meet the mechanical requirements of implants in a smaller size. The material has high density, is completely non-magnetic, has good X-ray absorption effect, and is compatible with MRI and CT examinations.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: a molybdenum-rhenium alloy material for human body implant, in which the rhenium content is 45-50% by mass and the rest is molybdenum; the material is reinforced with fibers and its tensile strength is ≥1300MPa; the material is processed by pressure and its density is ≥13.15g / cm 3 .

[0006] The present invention also provides a method for preparing a molybdenum-rhenium alloy material for human body implantation, comprising two preparation methods of powder metallurgy and vacuum electron beam melting.

[0007] 1. Powder metallurgy method 1 specifically includes the following steps:

[0008] S1: preparing molybdenum-rhenium mixed powder according to the weight ratio, using a V-type mixer;

[0009] S2: Pressing the molybdenum-rhenium mixed powder to obtain a compact, using a cold isostatic press or a press;

[0010] S3: The pressed green sheet is sintered at a temperature of 2000°C to 2350°C in a hydrogen or vacuum atmosphere to obtain a molybdenum-rhenium alloy green sheet, using a medium frequency induction sintering furnace;

[0011] S4: Extruding, forging, drawing or rolling the molybdenum-rhenium alloy metal billet, with a deformation rate of ≥65%, using an extruder, drawing machine, forging machine or rolling mill;

[0012] S5: After mechanical processing, cleaning and disinfection, the molybdenum-rhenium alloy material for human implantation can be obtained.

[0013] 2. Powder metallurgy method 2 specifically includes the following steps:

[0014] S1: preparing a molybdenum-rhenium mixed powder according to the weight ratio;

[0015] S2: hot pressing (or hot isostatic pressing) the molybdenum-rhenium mixed powder to obtain a blank;

[0016] S3: heating the pressed green sheet at a temperature of 2000°C to 2350°C or higher in a hydrogen or vacuum atmosphere to alloy the molybdenum and rhenium;

[0017] S4: extruding, forging, drawing or rolling the molybdenum-rhenium alloy metal billet;

[0018] S5: The material is mechanically processed and cleaned and disinfected to obtain the molybdenum-rhenium alloy material for human implantation.

[0019] 3. The vacuum electron beam melting method specifically comprises the following steps:

[0020] S1: preparing a molybdenum-rhenium mixed powder according to the weight ratio;

[0021] S2: Pressing the molybdenum-rhenium mixed powder to obtain a compact, using a V-type mixer;

[0022] S3: The pressed green sheet is sintered at a temperature of 2000°C to 2350°C in a hydrogen or vacuum atmosphere to obtain a molybdenum-rhenium alloy green sheet, using a medium frequency induction sintering furnace;

[0023] S4: performing vacuum electron beam melting to obtain a molybdenum-rhenium alloy ingot, using a vacuum electron beam melting furnace;

[0024] S5: Extruding, forging, drawing or rolling the molybdenum-rhenium alloy metal billet, with a deformation rate of ≥65%, using an extruder, drawing machine, forging machine or rolling mill;

[0025] S6: After mechanical processing, cleaning and disinfection, the molybdenum-rhenium alloy material for human implantation can be obtained.

[0026] Beneficial effects of the present invention:

[0027] Molybdenum and rhenium have good biocompatibility. Molybdenum is beneficial to biological growth, so the human body will hardly produce a human body rejection reaction with molybdenum-rhenium alloy. Rhenium has a rhenium effect, which can improve the strength and plasticity of molybdenum, improve the fatigue resistance of the material, and enable the material to withstand greater forces. The density of molybdenum-rhenium alloy is much higher than that of stainless steel (7.8g / cm 3 )、Titanium alloy(4.5g / cm 3 ), magnesium alloy) 1.74g / cm 3 ) and other materials, and it is non-magnetic and will not affect the angiography, making the surgery extremely convenient.

[0028] 1. The material of the present invention has good biocompatibility and can be well integrated with human biological tissues, with almost no human rejection problem or allergic reaction.

[0029] 2. The material of the present invention has high strength, good durability and ductility, and can meet the mechanical requirements of implants in a smaller size than other materials.

[0030] 3. The material of the present invention has high density, is completely non-magnetic, has good X-ray absorption effect, and is compatible with MRI and CT examinations. DETAILED DESCRIPTION

[0031] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0032] Example 1

[0033] A molybdenum-rhenium alloy material for human body implantation comprises the following components in terms of mass percentage: 47.5% rhenium content, and the remainder being molybdenum and other inevitable impurities.

[0034] A method for preparing the molybdenum-rhenium alloy material for human body implantation comprises the following steps:

[0035] S1: 475 g of rhenium powder and 525 g of molybdenum powder were mixed in a V-type mixer;

[0036] S2: isostatically pressing the molybdenum-rhenium mixed powder to obtain a compact, the pressure of which is 150 MPa;

[0037] S3: sintering the pressed green sheet at a temperature of 2150° C. in a hydrogen atmosphere to obtain a molybdenum-rhenium alloy green sheet;

[0038] S4: heating the molybdenum-rhenium alloy metal billet to 1350° C. and rolling;

[0039] S5: alkaline washing and cleaning of the material, and placing it in a hydrogen furnace at a temperature of 1300°C to remove the surface oxide layer, and S6 mechanically processing the material to obtain a product of corresponding size, and then cleaning and disinfecting to obtain a molybdenum-rhenium alloy material for human implantation.

[0040] The molybdenum-rhenium alloy material of this embodiment was compared with existing stainless steel, magnesium alloy and titanium alloy, and its density, strength and ductility were measured, and its biocompatibility was evaluated.

[0041] 1. Density measurement: Use a high-precision electronic balance to weigh the sample mass. To measure the sample volume, you can use the water displacement method or directly measure the sample's geometric dimensions and calculate the volume.

[0042] 2. Strength measurement: Use a universal material testing machine to measure the tensile strength and compressive strength of the sample.

[0043] Prepare standard samples (such as standard tensile specimens) and conduct tensile tests, and record the maximum load and the load at failure.

[0044] The tensile strength calculation formula is: $$\sigma_t = \frac{F}{A}$$, where $\sigma_t$ is the tensile strength, $F$ is the maximum load, and $A$ is the cross-sectional area.

[0045] 3. Biocompatibility testing, including in vitro cell compatibility testing and in vivo biocompatibility testing:

[0046] 3.1 In vitro cell compatibility test: The MTT method was used to test the toxicity of the sample extract to cells, and the L929 cell line was selected for the experiment; the details are as follows:

[0047] The samples were immersed in saline and the extracts were prepared according to the standard time;

[0048] L929 cells were seeded in a 96-well plate, and the sample extract was added for culture after the cells adhered to the wall;

[0049] After 24 h of incubation, MTT reagent was added, and DMSO was added to dissolve the generated purple crystals after incubation;

[0050] The absorbance (OD value) was measured using an enzyme-labeled instrument to calculate the cell viability.

[0051] Evaluation criteria: Cell survival rate above 90% is “excellent”, 80%-90% is “good”, and below 80% is “poor”.

[0052] 3.2 In vivo biocompatibility test: implant the sample into experimental animals (such as rats), observe the inflammatory response and tissue compatibility at the implantation site, and perform tissue sectioning and pathological analysis; the details are as follows:

[0053] Samples were taken at different time points (e.g., 1 week, 4 weeks, and 12 weeks) after implantation for histopathological examination.

[0054] The degree of inflammatory cell infiltration, fibrous encapsulation thickness, and tissue regeneration were evaluated.

[0055] Evaluation criteria: no obvious inflammatory reaction, thin fibrous wrapping, and good tissue regeneration are "excellent", mild inflammatory reaction, moderate fibrous wrapping, and good tissue regeneration are "good", and obvious inflammatory reaction, thick fibrous wrapping, and poor tissue regeneration are "poor".

[0056] Judgment of test results:

[0057] Density: Higher than stainless steel, magnesium alloy and titanium alloy, and meets the design requirements.

[0058] Strength: Reach or exceed 1300MPa, meeting high strength requirements.

[0059] Ductility: The ductility reaches more than 10%, showing good plasticity.

[0060] In vitro cytocompatibility: The results of the MTT test showed that the cell viability was higher than 90%, which was evaluated as "excellent".

[0061] In vivo biocompatibility: Histological sections and pathological analysis showed no obvious inflammatory response at the implant site, thin fibrous wrapping, and good tissue regeneration, which was evaluated as "excellent".

[0062] According to the above experimental methods and evaluation standards, the comparative data are as follows:

[0063]

[0064] Example 2

[0065] A molybdenum-rhenium alloy material for human body implantation comprises the following components in terms of mass percentage: 46% rhenium content, and the remainder being molybdenum and other inevitable impurities.

[0066] A method for preparing the molybdenum-rhenium alloy material for human body implantation comprises the following steps:

[0067] S1: 460 g of rhenium powder and 540 g of molybdenum powder were mixed in a V-type mixer;

[0068] S2: isostatically pressing the molybdenum-rhenium mixed powder to obtain a compact, the pressure of which is 150 MPa;

[0069] S3: sintering the pressed green sheet at a temperature of 2150° C. in a hydrogen atmosphere to obtain a molybdenum-rhenium alloy green sheet;

[0070] S4: hot isostatic pressing the molybdenum-rhenium alloy metal billet at a pressure of 160 MPa and a temperature of 160° C.;

[0071] S5: heating the molybdenum-rhenium alloy metal billet to 1350° C. and rolling;

[0072] S5: alkaline washing the material, then cleaning it, and placing it in a hydrogen furnace at a temperature of 1300°C to remove the surface oxide layer. S6: mechanically processing the material to obtain a product of corresponding size, and then cleaning and disinfecting it to obtain a molybdenum-rhenium alloy material for human implantation.

[0073] Example 3

[0074] A molybdenum-rhenium alloy material for human body implantation comprises the following components in terms of mass percentage: 46% rhenium content, and the remainder being molybdenum and other inevitable impurities.

[0075] A method for preparing the molybdenum-rhenium alloy material for human body implantation comprises the following steps:

[0076] S1: preparing a molybdenum-rhenium mixed powder according to the weight ratio;

[0077] S2: Pressing the molybdenum-rhenium mixed powder to obtain a compact, using a V-type mixer;

[0078] S3: The pressed green sheet is sintered at a temperature of 2150° C. in a hydrogen or vacuum atmosphere to obtain a molybdenum-rhenium alloy green sheet, using a medium frequency induction sintering furnace;

[0079] S4: performing vacuum electron beam melting to obtain a molybdenum-rhenium alloy ingot, using a vacuum electron beam melting furnace;

[0080] S5: Extruding, forging, drawing or rolling the molybdenum-rhenium alloy metal billet, with a deformation rate of ≥65%, using an extruder, drawing machine, forging machine or rolling mill;

[0081] S6: After mechanical processing, cleaning and disinfection, the molybdenum-rhenium alloy material for human implantation can be obtained.

[0082] The above implementation modes are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering and technical personnel in the field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A human body implant molybdenum-rhenium alloy material, characterized in that The rhenium content is 45~50%, and the remaining components are molybdenum and inevitable impurities.

2. A human body implantable molybdenum-rhenium alloy material according to claim 1, characterized in that: The molybdenum-rhenium alloy material needs to be reinforced with grain fibers, and its grain aspect ratio is ≥3.

3. A human body implantable molybdenum-rhenium alloy material according to claim 1, characterized in that: The molybdenum-rhenium alloy material needs to be processed by pressure, the total deformation rate of pressure processing is ≥65%, and the material density is ≥13.15g / cm 3 .

4. A human body implantable molybdenum-rhenium alloy material according to claim 1, characterized in that: The strength of the molybdenum-rhenium alloy material is ≥1200MPa, and the elongation at room temperature is ≥10%.

5. A method for preparing a molybdenum-rhenium alloy material for human body implantation according to claim 1, characterized in that: The preparation method includes but is not limited to powder metallurgy or vacuum electron beam melting.

6. A method for preparing a molybdenum-rhenium alloy material for human body implantation according to claim 5, characterized in that: When the molybdenum-rhenium alloy material preparation method is a powder metallurgy method, its preparation includes but is not limited to the following steps: S1: preparing a molybdenum-rhenium mixed powder according to the weight ratio; S2: pressing the molybdenum-rhenium mixed powder to obtain a compact; S3: sintering the pressed green sheet at a temperature above 2000° C. to 2350° C. in a hydrogen or vacuum atmosphere to obtain a molybdenum-rhenium alloy green sheet; S4: Extruding, forging, drawing or rolling the molybdenum-rhenium alloy metal billet, with a deformation rate of ≥65%; S5: The material is mechanically processed and cleaned and disinfected to obtain the molybdenum-rhenium alloy material for human implantation.

7. A method for preparing a molybdenum-rhenium alloy material for human body implantation according to claim 6, characterized in that: The powder metallurgy preparation method can also adopt the following steps: S1: preparing a molybdenum-rhenium mixed powder according to the weight ratio; S2: hot pressing or hot isostatic pressing the molybdenum-rhenium mixed powder to obtain a blank; S3: heating the pressed green sheet at a temperature of 2000°C to 2350°C or higher in a hydrogen or vacuum atmosphere to alloy the molybdenum and rhenium; S4: Extruding, forging, drawing or rolling the molybdenum-rhenium alloy metal billet, with a deformation rate of ≥65%; S5: The material is mechanically processed and cleaned and disinfected to obtain the molybdenum-rhenium alloy material for human implantation.

8. A method for preparing a molybdenum-rhenium alloy material for human body implantation according to claim 5, characterized in that: When the molybdenum-rhenium alloy material preparation method is vacuum electron beam melting, the preparation comprises the following steps: S1: preparing a molybdenum-rhenium mixed powder according to the weight ratio; S2: pressing the molybdenum-rhenium mixed powder to obtain a compact; S3: sintering the pressed green sheet at a temperature above 2000° C. to 2350° C. in a hydrogen or vacuum atmosphere to obtain a molybdenum-rhenium alloy green sheet; S4: performing vacuum electron beam melting on the material to obtain a molybdenum-rhenium alloy ingot; S5: Extruding, forging, drawing or rolling the molybdenum-rhenium alloy metal billet, with a deformation rate of ≥65%; S6: The material is mechanically processed and cleaned and disinfected to obtain the molybdenum-rhenium alloy material for human implantation.

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