A kind of method for preparing medical porous tantalum embedded material
Technical field
The present invention relates to a kind of porous medical metal embedded material, particularly relate to a kind of preparation method who is suitable for the medical porous tantalum embedded material of alternative load bone tissue.
Background technology
Porous medical metal embedded material has important and special purposes such as treatment osseous tissue wound and bone formation necrosis, and existing common this type material has porous metal stainless steel, porous metal titanium etc.Porous embedded material as osseous tissue wound and the use of bone formation necrosis therapeutic; Its porosity should reach 30~80%; And hole preferably all is communicated with and uniform distribution, or hole partly is communicated with and uniform distribution as required, makes it that both the osseous tissue growth phase with human body was consistent; Alleviated the weight of material itself again, implanted use to be fit to human body.
And refractory metals tantalum, because it has outstanding biocompatibility and mechanical property, its porous material is expected to as substituting conventional medical metallic biomaterials such as aforementioned, becomes the biomaterial mainly as bone necrosis's treatment.Since metal tantalum to human body harmless, nontoxic, have no side effect; And along with the develop rapidly of domestic and international medical science; As cognitive further the going deep into of body implanting material, the demand that people implant with the porous metal tantalum material human body becomes more and more urgent, and is also increasingly high to its requirement to tantalum.,, then be the heavy connection constituent material that guarantees freshman bone tissue's normal growth wherein if can have very high uniform distribution open pore and the physical and mechanical properties that adapts with human body as the medical embedded metal tantalum of porous.
As medical embedded porous metal material just as the porous metal material that kind be to be main working method basically with powder sintering, in particular for obtain porosity communication and equally distributed porous metal foam structure adopt the dipping after drying of metal-powder slurry on the organic foam body in the powder sintering to reburn to be called for short the foam impregnation method in the majority for knot.About the powder sintered porosity communication that obtains and common its Metal Mechanic Property of equally distributed porous metal material is not fine, and its major cause is how to arrange the support and the problem of eliminating in relation, the metal powder sintered process of subsiding of pore-forming medium on the technology.And all do not have good solution in the known bibliographical information and laissez-faire nature.
The bibliographical information that adopts metal powder sintered manufactured porous tantalum seldom particularly uses the porous tantalum powder sintering bibliographical information as purpose almost not have to obtain medical embedded material.Can reference be that publication number is CN200510032174, title " three-dimensional through hole or part hole are connected with each other porous metal foam and preparation method thereof " and CN200710152394, title " a kind of novel porous foam tungsten and preparation method thereof ".Yet porous metal that it obtained or for filtering material usefulness, or share for aerospace and other high-temperature field but not use as the medical metal embedded material, moreover the also non-porous tantalum of the porous metal of being processed.
About porous tantalum, US5282861 discloses a kind of perforate tantalum material and preparation thereof that is applied to spongy bone implant, cell and organizes susceptor.This porous tantalum is processed by pure commercial tantalum; It carries out the carbon skeleton that thermal destruction obtains with the polyurethane precursor is support, and this carbon skeleton is multiple dodecahedron, is the mesh-like structure in it; Integral body spreads all over micropore; Porosity can be up to 98%, the method for commercially pure tantalum through chemical vapour deposition, infiltration is attached on the carbon skeleton to form the porous metal microstructure again, abbreviates chemical deposition as.Its surperficial tantalum layer thickness of the porous tantalum material that this method obtained is between 40~60 μ m; In whole porous material, tantalum heavily accounts for 99%, and carbon skeleton weight then accounts for about 1%.Document is further put down in writing, the ultimate compression strength 50~70MPa of this porous material, Young's modulus 2.5~3.5GPa, tensile strength 63MPa, amount of plastic deformation 15%.But with its porous tantalum as medical embedded material, the mechanical property of its material such as ductility have obvious weak point, can have influence on the follow-up processing to porous tantalum material itself, for example cutting of profiled member etc.Also all there is such deficiency at the product that aforesaid metal powder sintered method obtained equally.Owing to the limitation of its preparation method, the finished product purity of acquisition is not enough, and the carbon skeleton residue is arranged again, causes biological safety to reduce.
Summary of the invention
The object of the present invention is to provide the preparation method of a kind of good biocompatibility, medical porous tantalum embedded material that mechanical strength is high.
The objective of the invention is to realize through following technique means:
A kind of method for preparing medical porous tantalum embedded material; Adopt foam impregnation method sintering to form; Its characteristics are that the solution and the tantalum powder that are mixed with organic binder bond and dispersion agent process tantalum powder slurry, and are cast in the organic foam body, and dipping is filled with tantalum powder slurry until organic foam body opening crack; Drying is removed the dispersion agent in the organic foam body that is cast with tantalum powder slurry then; Skimming treatment is to remove organic binder bond and organic foam body under protection of inert gas atmosphere, and sintering makes porous sintered body, cooling under the vacuum, and annealing and conventional aftertreatment make porous tantalum under the vacuum again; Said sintering step is that vacuum tightness is 10
-4Pa~10
-3Pa; Be warming up to 1500~1800 ℃, be incubated 120~240min, be chilled to 200~300 ℃ with 10~20 ℃/min with stove; Be warming up to 1500~1800 ℃, insulation 180~240min with 10~20 ℃/min again, be warming up to 2000~2200 ℃, insulation 120~360min with 5~10 ℃/min.
The porous tantalum that adopts preparation method according to the invention to make is specially adapted to the coupling member as load bone tissue injury or bone defect.Moreover, simple, the easy control of described preparing method's technology; Whole process of preparation is harmless, pollution-free, the toxicological harmless dust, and human body is had no side effect.And in the preparation process, preferentially be employed in the sintering process and can all decompose, there are not residual sticker, dispersion agent, organic foam body etc., will help guaranteeing the biocompatibility and the biological safety of embedded material.
Described organic binder bond preferably polyethylene alcohol also can adopt similar substances such as starch, TKK 021; Described dispersion agent adopts water, absolute ethyl alcohol etc., wherein preferably water usually.Described organic foam body optimization polyurethane foam also can be similar substances such as polyether ester foam.
Further characteristics of the present invention are: adopt its median size less than 43 μ m, oxygen level less than 0.1% ta powder; Adopting polyvinyl alcohol water solution is that sticker and water are that dispersion agent and described tantalum powder are processed tantalum powder slurry; The organic foam body is a polyurethane foam; Vacuum-drying removes and to anhydrate then, and the porosity of the porous tantalum of formation is between 50~70%, pore diameter 150~600 μ m.
Wherein, Z 150PH is heated to dissolving with zero(ppm) water; Adopt weight percent 2~8% (preferred 4~5%) polyvinyl alcohol water solution and ta powder to process tantalum powder slurry; Wherein, with weight be the ta powder of 6~9 parts (preferred 7 parts) to add weight be in 1 part the said polyvinyl alcohol water solution, stir and process starchiness; And to be cast in the aperture be 0.48~0.89mm, density 0.015g/cm
3~0.035g/cm
3, (preferred aperture is 0.56~0.72mm to hardness, density 0.025g/cm greater than 50 °
3, 50 °~80 ° of hardness) polyurethane foam in.
The preferential median size of selecting helps to reduce the content of impurity less than 43 μ m, oxygen level less than 0.1% ta powder, guarantees that material has mechanical property preferably; The selection aperture is 0.48~0.89mm, density 0.025g/cm
3~0.035g/cm
3, hardness helps to guarantee the porosity and the pore diameter of porous tantalum greater than 50 ° polyurethane foam.Processing condition have been optimized in the such technical finesse of the present invention, with the biocompatibility and the biological safety that guarantee to implant the porous tantalum material.
The present invention's further characteristics on the other hand are: exsiccant vacuum tightness keeps 10
-2~1Pa vacuum tightness, under protective atmosphere, for example vacuum tightness 10 then
-4~10
-3Pa, the skimming treatment of removing organic binder bond and organic foam body under 400 ℃~800 ℃ conditions of temperature; Sintering processes: vacuum tightness is 10
-4Pa~10
-3Pa; Be warming up to 1600~1800 ℃, be incubated 180~200min, be chilled to 200~300 ℃ with 12~15 ℃/min with stove; Be warming up to 1500~1800 ℃, insulation 220~240min with 16~19 ℃/min again; Be warming up to 2000~2200 ℃, insulation 250~320min with 5~8 ℃/min, can the filling with inert gas protection replace vacuum protection during the sintering process insulation; Carry out vacuum annealing at last and handle, wherein vacuum annealing is handled and is meant that process vacuum sintering continued keeps temperature to be in 1000~1250 ℃, soaking time 1~4 hour, and vacuum tightness is for being lower than 10
-4~10
-3Pa.
Above-mentioned skimming treatment condition also includes: the speed with 0.5 ℃/min~5 ℃/min progressively is warming up to 400~800 ℃, feeds with argon gas to constitute protective atmosphere and be incubated 30min~120min;
The vacuum sintering condition is: vacuum tightness is 10
-4Pa~10
-3Pa is warming up to 1800 ℃, is incubated 200min, is chilled to 200~300 ℃ with stove with 13 ℃/min, is warming up to 1800 ℃, insulation 230min with 17 ℃/min again, is warming up to 2000~2200 ℃, insulation 300min with 7 ℃/min;
Cooling conditions after the vacuum sintering also includes: vacuum tightness is lower than 10
-3Pa not to be higher than 25 ℃/min, to be not less than 10 ℃/min and gradually to fall the rate of cooling mode, and sintered porous bodies segmentation cooling is cooled to 800 ℃, and each section soaking time 30min~90min cools to normal temperature then with the furnace;
The vacuum annealing condition also includes: vacuum tightness is lower than 10
-4Pa rises to 1000~1250 ℃ with the speed that is not higher than 30 ℃/min, insulation 4h~6h; Again with after earlier slow soon to be not less than 5 ℃/min but the rate of cooling segmentation that is not higher than 30 ℃/min is cooled to room temperature, the soaking time of each section tapers off and is no more than in 1.5h~3h and selects.
Further characteristics are on this basis: 60~100 ℃ of said vacuum drying drying temperatures, 4~8 hours time of drying; Said skimming treatment condition also includes: progressively be warming up to 600~800 ℃; Feed the formation protective atmosphere with pure argon gas (99.9999%); Speed with 1~5 ℃/min rises to 400 ℃ from room temperature, and insulation 30~60min rises to 600~800 ℃ with the speed of 0.5~1.5 ℃/min from 400 ℃; Insulation 60~120min, said vacuum sintering condition is: reciprocal of duty cycle is 10
-4Pa~10
-3Pa is warming up to 1800 ℃, is incubated 200min, is chilled to 200~300 ℃ with stove with 13 ℃/min, is warming up to 1800 ℃, insulation 230min with 17 ℃/min again, is warming up to 2000~2200 ℃, insulation 300min with 7 ℃/min;
Cooling conditions after the vacuum sintering also includes: vacuum tightness is 10
-4Pa~10
-3Pa; Speed with 10~20 ℃/min is cooled to 1500~1600 ℃, insulation 30~60min; Speed with 12~20 ℃/min is cooled to 1200~1250 ℃, insulation 60~90min; Speed with 10~20 ℃/min is cooled to 800 ℃, then furnace cooling; Said vacuum annealing condition also includes: the speed with 15~30 ℃/min rises to 1000~1250 ℃, insulation 240~480min, and vacuum tightness is 10
-4Pa~10
-3Pa, the speed with 5~10 ℃/min is cooled to 1000 ℃ again, insulation 90~180min, vacuum tightness is 10
-4Pa~10
-3Pa; Speed with 10~20 ℃/min is cooled to 800 ℃, insulation 60~120min, and vacuum tightness is lower than 10
-4Pa; Speed with 20~30 ℃/min is cooled to room temperature, and vacuum tightness is 10
-4Pa~10
-3Pa.
Be the content that helps to reduce impurity in the porous tantalum wherein, improve biocompatibility and biological safety and reach mechanical property well vacuum-drying, skimming treatment etc.; To the optimization of organic foam body material to solve the problem of subsiding that is difficult for of foam framework in the sintering process; To the optimization of process conditions of sintering and annealing steps, further improve porous tantalum mechanical property such as ductility, reduce the fracture rate of sintering neck.
The porous tantalum material that aforesaid method makes is lower than 0.5% through its foreign matter content of test; This porous tantalum finished product even pore distribution and connection, density 5.00~8.33g/cm
3, porosity 50~70%, pore diameter 150~600 μ m, Young's modulus 2.5~4.0GPa, flexural strength 130~150MPa, ultimate compression strength 75~88MPa, unit elongation 9.3%~10.2%.Porous tantalum material of the present invention not only biocompatibility, security is good, and the special intensity of mechanical property is high, is suitable for very much substituting the osseous tissue at human bearing position.
Description of drawings
Fig. 1 is the scanning electron microscope analysis figure (SEM figure) of the porous tantalum structure of preparing method's preparation according to the invention;
Can be observed from accompanying drawing: the high hole of porous tantalum according to the invention, even pore distribution is communicated with.Can find out from accompanying drawing that porous tantalum of the present invention open pore helps that scleroblast adheres to, differentiation and growth, promote growing into of bone, can strengthen being connected between implant and the bone, be beneficial to the realization biological fixation.
Embodiment
Through embodiment the present invention is carried out concrete description below; Be necessary to be pointed out that at this following examples only are used for the present invention is further specified; Can not be interpreted as the restriction to protection domain of the present invention, the technician in this field can make some nonessential improvement and adjustment to the present invention according to the invention described above content.
Embodiment 1: weighing polyvinyl alcohol 12.5g, put into the container that 240ml zero(ppm) water is housed; Placing it in heats on the electric furnace and stir makes it to become polyvinyl alcohol water solution.With 200g balance weighing median size less than 43 microns, oxygen level less than 0.1% tantalum powder 60g, add 50ml refrigerative polyvinyl alcohol water solution, mix, make it to become tantalum powder slurry.(mean pore size is 0.48mm, density 0.025g/cm to select 10 * 10 * 30mm cellular polyurethane foam for use
3, 50 ° of hardness) and put into wherein cast, fill with tantalum powder slurry until the polyurethane foam hole, the polyurethane foam that goes out to be filled tantalum powder slurry with clip is put into porcelain dish.Dry in vacuum drying oven, 60 ℃ of drying temperatures, 8 hours time of drying, vacuum tightness keeps 1Pa.Skimming treatment: vacuum tightness is lower than 10
-4Pa, 600 ℃ of temperature, soaking time 120 minutes.Vacuum sintering: said sintering step is that vacuum tightness is 10
-4Pa~10
-3Pa is warming up to 1800 ℃, is incubated 200min, is chilled to 200~300 ℃ with stove with 13 ℃/min, is warming up to 1800 ℃, insulation 230min with 17 ℃/min again, is warming up to 2000~2200 ℃, insulation 300min with 7 ℃/min; The protection of sintering process applying argon gas is removed surface dirt and dirt behind the taking-up product, and the sample that makes carries out conventional aftertreatment again and gets the porous tantalum finished product.
The contriver detects by porous material density, porosity, aperture and the various mechanical property of standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001 to above-mentioned porous tantalum finished product: its foreign matter content is lower than 0.5% finished product; Its even pore distribution and connection, density 6.7g/cm
3, porosity 56%, hole mean diameter 300 μ m, Young's modulus 3.0GPa, flexural strength 150MPa, ultimate compression strength 82MPa, unit elongation 9.8%.
Embodiment 2: weighing polyvinyl alcohol 10g, put into the container that 200ml zero(ppm) water is housed; Placing it in heats on the electric furnace and stir makes it to become polyvinyl alcohol water solution.With 200g balance weighing median size less than 43 microns, oxygen level less than 0.1% tantalum powder 40g, add the 32ml polyvinyl alcohol water solution, mix, make it to become tantalum powder slurry.(mean pore size is 0.56mm, density 0.030g/cm to select 10 * 10 * 25mm cellular polyurethane foam for use
3, 60 ° of hardness) and put into wherein cast, fill with tantalum powder slurry until the polyurethane foam hole, the polyurethane foam that goes out to be filled tantalum powder slurry with clip is put into porcelain dish.Dry in vacuum drying oven, 100 ℃ of drying temperatures, 4 hours time of drying, vacuum tightness keeps 10
-2Pa.Skimming treatment: vacuum tightness 10
-4Pa, 800 ℃ of temperature, soaking time 120 minutes.Vacuum sintering: said sintering step is that vacuum tightness is 10
-4Pa~10
-3Pa; Be warming up to 1600 ℃, be incubated 240min, be chilled to 200~300 ℃ with 10 ℃/min with stove; Be warming up to 1500 ℃, insulation 180min with 20 ℃/min again, be warming up to 2000~2200 ℃, insulation 360min, the protection of sintering process applying argon gas with 5 ℃/min; Remove surface dirt and dirt after taking out product, the sample that makes carries out conventional aftertreatment again and gets the porous tantalum finished product.
The contriver detects by porous material density, porosity, aperture and the various mechanical property of standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001 to above-mentioned porous tantalum finished product: its foreign matter content is lower than 0.5% finished product; Its even pore distribution and connection, density 8.0g/cm
3, porosity 66%, hole mean diameter 400 μ m, Young's modulus 3.5GPa, flexural strength 140MPa, ultimate compression strength 75MPa, unit elongation 10.1%.
Embodiment 3: weighing polyvinyl alcohol 11g, put into the container that 220ml zero(ppm) water is housed; Placing it in heats on the electric furnace and stir makes it to become polyvinyl alcohol water solution.With 200g balance weighing median size less than 43 microns, oxygen level less than 0.1% tantalum powder 45g, add the 36ml polyvinyl alcohol water solution, mix, make it to become tantalum powder slurry.(mean pore size is 0.70mm, density 0.035g/cm to select 8 * 8 * 25mm cellular polyurethane foam for use
3, 70 ° of hardness) and put into wherein cast, fill with tantalum powder slurry until the polyurethane foam hole, the polyurethane foam that goes out to be filled tantalum powder slurry with clip is put into porcelain dish.Dry in vacuum drying oven, 80 ℃ of drying temperatures, 6 hours time of drying, vacuum tightness keeps 10
-1Pa.Skimming treatment: vacuum tightness 10
-3Pa, 700 ℃ of temperature, soaking time 90 minutes.Vacuum sintering: said sintering step is that vacuum tightness is 10
-4Pa~10
-3Pa; Be warming up to 1800 ℃, be incubated 120min, be chilled to 200~300 ℃ with 20 ℃/min with stove; Be warming up to 1800 ℃, insulation 240min with 10 ℃/min again, be warming up to 2000~2200 ℃, insulation 120min, the protection of sintering process applying argon gas with 10 ℃/min; Remove surface dirt and dirt after taking out product, the sample that makes carries out conventional aftertreatment again and gets the porous tantalum finished product.
The contriver detects by porous material density, porosity, aperture and the various mechanical property of standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001 to above-mentioned porous tantalum finished product: its foreign matter content is lower than 0.5% finished product; Its even pore distribution and connection, density 5.0g/cm
3, porosity 70%, hole mean diameter 450 μ m, Young's modulus 5.5GPa, flexural strength 130MPa, ultimate compression strength 86MPa, unit elongation 9.5%.
Embodiment 4: weighing polyvinyl alcohol 12g, put into the container that 230ml zero(ppm) water is housed; Placing it in heats on the electric furnace and stir makes it to become polyvinyl alcohol water solution.With 200g balance weighing median size less than 43 microns, oxygen level less than 0.1% tantalum powder 50g, add the 40ml polyvinyl alcohol water solution, mix, make it to become tantalum powder slurry.(aperture is 0.60mm, density 0.027g/cm to select 12 * 12 * 30mm cellular polyurethane foam for use
3, 80 ° of hardness) and put into wherein cast, fill with tantalum powder slurry until the polyurethane foam hole, the polyurethane foam that goes out to be filled tantalum powder slurry with clip is put into porcelain dish.Dry in vacuum drying oven, 90 ℃ of drying temperatures, 5 hours time of drying, vacuum tightness keeps 1Pa.Skimming treatment: vacuum tightness 10
-4~10
-3Pa, 500 ℃ of temperature, soaking time 120 minutes.Vacuum sintering: said sintering step is that vacuum tightness is 10
-4Pa~10
-3Pa; Be warming up to 1700 ℃, be incubated 210min, be chilled to 200~300 ℃ with 13 ℃/min with stove; Be warming up to 1600 ℃, insulation 210min with 15 ℃/min again, be warming up to 2000~2200 ℃, insulation 260min, the protection of sintering process applying argon gas with 8 ℃/min; Remove surface dirt and dirt after taking out product, the sample that makes carries out conventional aftertreatment again and gets the porous tantalum finished product.
The contriver detects by porous material density, porosity, aperture and the various mechanical property of standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001 to above-mentioned porous tantalum finished product: its foreign matter content is lower than 0.5% finished product; Its even pore distribution and connection, density 8.33g/cm
3, porosity 50%, hole mean diameter 350 μ m, Young's modulus 2.7GPa, flexural strength 142MPa, ultimate compression strength 81MPa, unit elongation 9.8%.
Embodiment 5: a kind of porous tantalum, and it is raw material less than 43 μ m, oxygen level less than 0.1% ta powder with particle diameter, is that binder solution is processed tantalum powder slurry with the polyvinyl alcohol water solution, and is cast in the polyurethane foam carrier; Vacuum-drying then, skimming treatment, vacuum sintering, vacuum annealing and conventional aftertreatment make.
Wherein, the polyurethane foam of selecting for use, its aperture is 0.72~0.56mm, density 0.025g/cm
3, 50 °~80 ° of hardness;
Vacuum-drying: vacuum tightness keeps 10
-2~1Pa is to remove the moisture in the polyurethane foam of filling with tantalum powder slurry;
Skimming treatment: under protection of inert gas atmosphere or vacuum tightness 10
-4~10
-3Pa, 400 ℃~800 ℃ of temperature, and soaking time 30~120 minutes is to remove Z 150PH and polyurethane foam wherein;
Vacuum sintering: said sintering step is that vacuum tightness is 10
-4Pa~10
-3Pa is warming up to 1650 ℃, is incubated 190min, is chilled to 200~300 ℃ with stove with 16 ℃/min, is warming up to 1800 ℃, insulation 200min with 18 ℃/min again, is warming up to 2000~2200 ℃, insulation 270min with 6 ℃/min;
Vacuum annealing: keep temperature to be in 1000~1250 ℃ through the vacuum sintering continued, soaking time 1~4 hour, vacuum tightness are 10
-4~10
-3Pa handles to carry out stress relief annealing; The sample that makes carries out conventional aftertreatment again and gets the porous tantalum finished product.
The contriver detects by porous material density, porosity, aperture and the various mechanical property of standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001 to above-mentioned porous tantalum finished product: its foreign matter content is lower than 0.5% finished product; Its even pore distribution and connection, density 6.3g/cm
3, porosity 62%, hole mean diameter 220 μ m, Young's modulus 3.3GPa, flexural strength 136MPa, ultimate compression strength 84MPa, unit elongation 10.2%.
In the method that the foregoing description 5 provides, we can also do other selections to wherein each kind of condition can obtain porous tantalum of the present invention equally.
Gained porous tantalum finished product is pressed preceding method and is detected:
Embodiment |
6 |
7 |
8 |
Density (g/cm
3)
|
6.9 |
7.5 |
7.8 |
Porosity (%) |
50 |
64 |
70 |
Aperture (μ m) |
170 |
410 |
280 |
Young's modulus (GPa) |
2.6 |
3.5 |
4.0 |
Flexural strength (MPa) |
140 |
130 |
150 |
Ultimate compression strength (MPa) |
80 |
88 |
76 |
Unit elongation (%) |
9.5 |
9.8 |
10.0 |