A kind of porous tantalum being applicable to alternative human dentale tissue
The present patent application is the divisional application of application number 201110295867.0, the applying date on 09 29th, 2011, denomination of invention " a kind of preparation method being applicable to the porous tantalum of alternative human dentale tissue ".
Technical field
The present invention relates to a kind of preparation method of medical metal implanted material, especially relate to a kind of preparation method being applicable to the medical porous metal implant material of alternative human dentale tissue.
Background technology
Porous medical metal implanted material has the downright bad and alternative dense bone tissue for the treatment of osseous tissue wound, bone formation purposes as important and special in dentale etc., and showing common this kind of material has porous metal stainless steel, porous metal titanium etc.As the porous embedded material that osseous tissue wound and bone formation necrosis therapeutic use, its porosity should reach 30 ~ 80%, and hole is preferably all communicated with and is uniformly distributed, or make it both consistent with the bone growth of human body as required, alleviate again the weight of material itself, implant with applicable human body and use.
And refractory metals tantalum, because it has outstanding biocompatibility, its porous material is expected to the conventional medical metallic biomaterial such as aforementioned as an alternative.Due to metal tantalum to human body harmless, nontoxic, have no side effect, and along with the develop rapidly of domestic and international medical science, to tantalum going deep into further as body implanting material cognition, the demand of people to human body implantation porous metal tantalum material becomes more and more urgent, also more and more higher to its requirement.Wherein as the medical embedded metal tantalum of porous, if can have the very high physical and mechanical properties being uniformly distributed open pore and adapting with human body, then it is expected to as a kind of novel osseous tissue equivalent material.
As medical embedded porous metal material just as porous metal material be main working method with powder sintering like that substantially, especially obtain porosity communication and equally distributed porous metal foam structure adopt the dipping of the metal-powder slurry in powder sintering on Organic Foam Material after drying reburn and tie that to be called for short foam impregnation method in the majority.About powder sintered obtained porous metal material usually its Metal Mechanic Property be not very well, its major cause how technique arranges the problem of subsiding in the support of pore-forming medium and elimination relation, metal powder sintered process.And all there is no good solution in known bibliographical information and let alone nature.
Adopt metal powder sintered legal system to make the bibliographical information of porous tantalum seldom, particularly almost do not have by the porous tantalum powder sintering bibliographical information obtained for the purpose of medical embedded material use.Can reference be publication number be CN200510032174, title " three-dimensional through hole or some perforations are connected with each other porous metal foam and preparation method thereof " and CN200710152394, title " a kind of porous foam tungsten and preparation method thereof ".But its porous metal obtained or for filtering material use, or share for aerospace and other high-temperature field but not use as medical metal implanted material, moreover the porous metal processed also non-porous tantalum.
About porous tantalum, US5282861 discloses and is a kind ofly applied to cancellous bone implants, the perforate tantalum material of biological cells and tissues susceptor and preparation thereof.This porous tantalum is made up of pure business tantalum, it carries out carbon skeleton that thermal destruction obtains for support with polyurethane precursor, this carbon skeleton is multiple dodecahedron, it is mesh-like structure in it, entirety spreads all over micropore, porosity can up to 98%, then by commercially pure tantalum by the methods combining of chemical vapour deposition, infiltration to carbon skeleton to form porous metal microstructure, referred to as chemical deposition.The tantalum layer thickness on its surface of porous tantalum material that this method obtains is between 40 ~ 60 μm; In whole porous material, tantalum heavily accounts for 99%, and carbon skeleton weight then accounts for about 1%.Document is recorded further, 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 using it as dense bone tissue as the porous tantalum of the medical embedded materials such as dentale, mechanical property such as ductility, ultimate compression strength, the flexural strength etc. of its material have obvious weak point, and the follow-up processing to porous tantalum material itself can be had influence on, the cutting etc. of such as profiled member.Also all there is such deficiency in the product obtained in aforesaid metal powder sintered method equally.
Summary of the invention
The object of the present invention is to provide the medical porous tantalum being applicable to alternative human dentale tissue that a kind of biocompatibility, mechanical property are good.
The object of the invention is to be realized by following technique means:
A kind of preparation method being applicable to alternative human dentale tissue porous tantalum, tantalum powder and pore-forming material, forming agent are mixed into mixed powder, then through granulation, be injected into the medical porous metal implant material that mould molding, the demoulding, degreasing, sintering and thermal treatment obtain alternative dentale tissue; It is characterized in that: described pore-forming material is one or more in sodium bicarbonate, urea, sodium-chlor, methylcellulose gum, ethyl cellulose, described forming agent is one or more in polyvinyl alcohol, stearic acid, Zinic stearas, paraffin, synthetic rubber; Described skimming processes is progressively warming up to 400 ~ 800 DEG C with the speed of 0.5 DEG C/min ~ 3 DEG C/min, and pass into argon gas and formed protective atmosphere and be incubated 60min ~ 240min, described sintering step is vacuum tightness is 10
-4pa ~ 10
-3pa, be warming up to 1500 ~ 1800 DEG C with 10 ~ 20 DEG C/min, be incubated 120 ~ 240min, be chilled to 200 ~ 300 DEG C with stove, be warming up to 1500 ~ 1800 DEG C, insulation 180 ~ 240min with 10 ~ 20 DEG C/min again, be warming up to 2000 ~ 2200 DEG C, insulation 120 ~ 360min with 5 ~ 10 DEG C/min.
In the R&D process of medical porous tantalum material, syntheti c route is numerous, but contriver creatively proposes and adopts above-mentioned processing step to prepare fine and close medical porous tantalum embedded material, the above-mentioned sintering process particularly adopted, idiosome is made to become heating element, thus sinter evenly, thorough, while ensureing excellent biocompatibility, also effectively improve mechanical strength.
In order to make the porous tantalum material porosity of the alternative dentale tissue obtained suitable, to make biocompatibility excellent, improve the mechanical property of its material simultaneously, above-mentioned granulation process be working temperature be 450 ~ 650 DEG C, described mixed powder is a granulated into particle diameter not higher than the circular granular of 20 μm under being 12 ~ 15MPa by operating pressure, the temperature described circular granular being injected into mould is 380 ~ 540 DEG C, pressure is 72 ~ 90MPa.
The present invention adopt Ta powder median size is less than 43 microns, oxygen level is less than 0.1%, is commercially available prod; Above-mentioned pore-forming material, forming agent are also commercially available prod.Vacuum environment of the present invention preferably adopts vacuum tightness to be 10
-4pa ~ 10
-3the vacuum condition of Pa.
In R&D process, contriver studies discovery further, if control bad in above-mentioned preparation, though the medical embedded material that is suitable for alternative dentale as mentioned above can be obtained but conforming product rate is not high: as difficult in powder pressing forming, after pressing part easily there is layering, uneven, degreasing rear section there will be the technical problems such as crackle.
Shaping easier in order to make in powder compaction process, thus raising yield rate, finished product hole homogeneity, make preparation process more stable, in above-mentioned mixed powder, the consumption of forming agent is 5 ~ 10%, the consumption of pore-forming material is 20 ~ 30%, surplus is tantalum powder, (be the unit directly calculated by the situation of final porous tantalum material in volumn concentration in volumn concentration, the quality weighing of its correspondence is calculated) in above-mentioned mixed powder weighs or according to the densometer of respective substance, more preferably forming agent is that paraffin accounts for 7 ~ 9%, pore-forming material is that ethyl cellulose accounts for 26 ~ 29%, surplus is tantalum powder, further be preferably paraffin and account for 8%, ethyl cellulose accounts for 27%, surplus is tantalum powder, all in volumn concentration, above-mentioned demould time is preferably 6 ~ 9S, more preferably 7S.
In order to make idiosome in skimming processes more stable, reduce the part idiosome distortion easily occurred, aperture is uneven, thus improve yield rate further, quality of production stability, in the preparation of the porous tantalum material of above-mentioned alternative dentale tissue, skimming processes is preferably progressively warming up to 400 ~ 800 DEG C with the speed of 2.5 ~ 3 DEG C/min, pass into argon gas and formed protective atmosphere and be incubated 150min ~ 240min, further preferably progressively be warming up to 400 ~ 800 DEG C with the speed of 2.5 DEG C/min, pass into argon gas and formed protective atmosphere and be incubated 220min, most preferably, above-mentioned degreasing rises to 400 DEG C with the speed of 1 ~ 3 DEG C/min from room temperature, insulation 60 ~ 120min, 600 ~ 800 DEG C are risen to from 400 DEG C with the speed of 1.5 ~ 2.5 DEG C/min, insulation 180 ~ 240min, the preferred temperature of above-mentioned granulation process is 510 ~ 535 DEG C, operating pressure is the circular granular under 13MPa, described mixed powder being a granulated into particle diameter 10 ~ 20 μm (being more preferably 13 μm), is 465 ~ 490 DEG C, pressure is 83 ~ 85MPa by injection molding for described circular granular temperature.
Sinter to make idiosome evenly, thorough, make the medical porous tantalum strength of materials that obtains higher, it is 10 that above-mentioned sintering step is preferably vacuum tightness
-4pa ~ 10
-3pa, be warming up to 1500 ~ 1800 DEG C with 12 ~ 15 DEG C/min, be incubated 180 ~ 200min, be chilled to 200 ~ 300 DEG C with stove, be warming up to 1500 ~ 1800 DEG C, insulation 220 ~ 240min with 16 ~ 19 DEG C/min again, be warming up to 2000 ~ 2200 DEG C, insulation 250 ~ 320min with 5 ~ 10 DEG C/min.
Further feature is on this basis: described skimming treatment condition also includes: be progressively warming up to 600 ~ 800 DEG C, specifically pass into formation protective atmosphere with pure argon gas (99.9999%), 400 DEG C are risen to from room temperature with the speed of 1 ~ 3 DEG C/min, insulation 60 ~ 120min, 600 ~ 800 DEG C are risen to from 400 DEG C, insulation 180 ~ 240min with the speed of 1.5 ~ 2.5 DEG C/min; Described vacuum sintering condition also includes: vacuum tightness is 10
-4pa ~ 10
-3pa, is warming up to 1800 DEG C with 13 DEG C/min, is incubated 200min, is chilled to 200 ~ 300 DEG C with stove, then is warming up to 1800 DEG C, insulation 230min with 17 DEG C/min, is warming up to 2000 ~ 2200 DEG C, insulation 300min with 7 DEG C/min; Cooling conditions after vacuum sintering also includes: vacuum tightness is 10
-4pa ~ 10
-3pa; 1500 ~ 1600 DEG C are cooled to, insulation 30 ~ 60min with the speed of 10 ~ 20 DEG C/min; 1200 ~ 1250 DEG C are cooled to, insulation 60 ~ 90min with the speed of 12 ~ 20 DEG C/min; 800 DEG C are cooled to, then furnace cooling with the speed of 10 ~ 20 DEG C/min; Described heat-treat condition also includes: rise to 1000 ~ 1250 DEG C with the speed of 15 ~ 30 DEG C/min, and insulation 240 ~ 480min, vacuum tightness is 10
-4pa ~ 10
-3pa, then be cooled to 1000 DEG C with the speed of 5 ~ 10 DEG C/min, insulation 90 ~ 180min, vacuum tightness is 10
-4pa ~ 10
-3pa; Be cooled to 800 DEG C with the speed of 10 ~ 20 DEG C/min, insulation 60 ~ 120min, vacuum tightness is 10
-4pa; Be cooled to room temperature with the speed of 20 ~ 30 DEG C/min, vacuum tightness is 10
-4pa ~ 10
-3pa.
The character of metal tantalum and niobium is extremely similar, and aforesaid method is equally also applicable to the preparation of medical porous niobium material.
Preparation methods for porous metal materials of the present invention have employed injection moulding, makes the content of impurity in final porous tantalum material extremely low, effectively improves biocompatibility and biological safety; To the optimization of process conditions of granulation of the present invention, injection molding, degreasing, sintering and annealing steps, make that yield rate is high, finished product aperture homogeneity is better, make that preparation process is more stable, quality stability good, effectively eliminate thermal stresses, make porous tantalum materials microstructure evenly, all be improved with the mechanical property such as intensity, the toughness that improve porous tantalum further simultaneously, the above-mentioned sintering process particularly adopted, idiosome is made to become heating element, thus sinter evenly, thorough, mechanical strength significantly improves.As everyone knows, the qualification rate of product, production stability are determined by manual operation factor and operational path itself determines, manual operation after all can be in high standardization and be tending towards normal level, therefore quality of production stability determines primarily of technique own, its product qualified rate of preparation technology of the present invention is high, administration measure, and conforming product rate is up to 92.5% ~ 95.0%.The porous tantalum finished product even pore distribution that the present invention obtains and be communicated with, good biocompatibility.Through its foreign matter content of test can lower than 0.2%, density can reach 11.67 ~ 13.34g/cm
3, porosity can reach 20 ~ 30%, and pore diameter can reach 12 ~ 25 μm, Young's modulus can reach 4.5 ~ 6.0Gpa, unit elongation reaches 12.0 ~ 13.8%, flexural strength can reach 160 ~ 180Mpa, ultimate compression strength can reach 115 ~ 130Mpa; It is suitable for the medical embedded material of alternative human dentale tissue very much.
Embodiment
Below by embodiment, the present invention is specifically described; what be necessary to herein means out is that following examples are only used to further illustrate the present invention; can not be interpreted as limiting the scope of the invention, person skilled in art can make some nonessential improvement and adjustment according to the invention described above content to the present invention.
Embodiment 1: take paraffin, median size be less than 43 microns of oxygen levels be less than 0.1% tantalum powder and ethyl cellulose be mixed into mixed powder, wherein paraffin accounts for 8%, ethyl cellulose accounts for 27%, tantalum powder accounts for 65%, all in volumn concentration.Granulation: working temperature be 510 ~ 520 DEG C, described mixed powder to be a granulated into the circular granular of particle diameter 10 ~ 13 μm by operating pressure under being 12 ~ 13MPa.Injection molding: the temperature described circular granular being injected into mould is 465 ~ 490 DEG C, pressure is 83 ~ 85MPa.Demould time: 6 ~ 7S.Skimming treatment: vacuum tightness 10
-4pa, rises to 400 DEG C with the speed of 1 ~ 3 DEG C/min from room temperature, and insulation 60 ~ 120min, rises to 600 ~ 800 DEG C with the speed of 1.5 ~ 2.5 DEG C/min from 400 DEG C, insulation 180 ~ 240min.Vacuum sintering: vacuum tightness is 10
-4pa ~ 10
-3pa; be warming up to 1800 DEG C with 13 DEG C/min, be incubated 200min, be chilled to 200 ~ 300 DEG C with stove; 1800 DEG C, insulation 230min is warming up to again with 17 DEG C/min; 2000 ~ 2200 DEG C, insulation 300min is warming up to 7 DEG C/min; sintering process applying argon gas is protected; surface dirt and dirt is removed, obtained porous tantalum finished product after taking out product.
Contriver detects the porous material density of above-mentioned porous tantalum finished product, porosity, aperture and various mechanical property by standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001: its foreign matter content is lower than 0.2%, its even pore distribution, density 12.54g/cm
3, porosity 25%, pore mean diameters 23 μm, Young's modulus 5.0GPa, unit elongation 12.3%, flexural strength 172MPa, ultimate compression strength 120MPa.This porous tantalum is suitable for the medical embedded material of alternative human dentale tissue very much.
Embodiment 2: weighing polyvinyl alcohol, median size be less than 43 microns of oxygen levels be less than 0.1% tantalum powder and sodium bicarbonate be mixed into mixed powder, wherein polyvinyl alcohol accounts for 6%, sodium bicarbonate accounts for 29%, tantalum powder accounts for 65%, all in volumn concentration.Granulation: working temperature be 450 DEG C, described mixed powder to be a granulated into the circular granular of particle diameter 20 μm by operating pressure under being 15MPa.Injection molding: the temperature described circular granular being injected into mould is 540 DEG C, pressure is 90MPa.Demould time: 9S.Skimming treatment: vacuum tightness 10
-4pa, with the temperature rise rate of 1 DEG C/min from room temperature to 400 DEG C, insulation 60min; 800 DEG C are warming up to from 400 DEG C again, soaking time 180 minutes with the temperature rise rate of 2.5 DEG C/min.Vacuum sintering: vacuum tightness is 10
-4pa; be warming up to 1500 DEG C with 12 DEG C/min, be incubated 200min, be chilled to 200 ~ 300 DEG C with stove; 1800 DEG C, insulation 220min is warming up to again with 16 DEG C/min; 2000 ~ 2200 DEG C, insulation 320min is warming up to 5 DEG C/min; sintering process applying argon gas is protected; remove surface dirt and dirt after taking out product, obtained sample carries out conventional aftertreatment again and obtains porous tantalum finished product.
Contriver detects the porous material density of above-mentioned porous tantalum finished product, porosity, aperture and various mechanical property by standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001: its foreign matter content is lower than 0.2%, its even pore distribution, density 11.74g/cm
3, porosity 30%, pore mean diameters 24 μm, Young's modulus 4.5GPa, unit elongation 12.8%, flexural strength 160MPa, ultimate compression strength 117MPa.This porous tantalum is suitable for the medical embedded material of alternative human dentale tissue very much.
Embodiment 3: take Zinic stearas, median size be less than 43 microns of oxygen levels be less than 0.1% tantalum powder and methylcellulose gum be mixed into mixed powder, wherein Zinic stearas accounts for 10%, methylcellulose gum accounts for 23%, tantalum powder accounts for 67%, all in volumn concentration.Granulation: working temperature be 650 DEG C, described mixed powder to be a granulated into the circular granular of particle diameter 10 μm by operating pressure under being 12MPa.Injection molding: the temperature described circular granular being injected into mould is 380 DEG C, pressure is 72MPa.Demould time: 6S.Skimming treatment: vacuum tightness 10
-4pa, with the temperature rise rate of 3 DEG C/min from room temperature to 400 DEG C, insulation 120min; 750 DEG C are warming up to from 400 DEG C again, soaking time 240 minutes with the temperature rise rate of 1.5 DEG C/min.Vacuum sintering: vacuum tightness is 10
-3pa; be warming up to 1800 DEG C with 15 DEG C/min, be incubated 200min, be chilled to 200 ~ 300 DEG C with stove; 1600 DEG C, insulation 240min is warming up to again with 19 DEG C/min; 2000 ~ 2200 DEG C, insulation 320min is warming up to 10 DEG C/min; sintering process applying argon gas is protected; cooling is come out of the stove, and removes product surface dust and dirt, and obtained sample carries out conventional aftertreatment again and obtains porous tantalum finished product.
Contriver detects the porous material density of above-mentioned porous tantalum finished product, porosity, aperture and various mechanical property by standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001: its foreign matter content is lower than 0.2%, its even pore distribution, density 13.30g/cm
3, porosity 20%, pore mean diameters 20 μm, Young's modulus 5.0GPa, unit elongation 12.05%, flexural strength 178MPa, ultimate compression strength 125MPa.This porous tantalum is suitable for the medical embedded material of alternative human dentale tissue very much.
Embodiment 4: a kind of porous tantalum, it is less than 43 μm, the oxygen level ta powder that is less than 0.1% with particle diameter, polyvinyl alcohol and sodium bicarbonate powder mix are raw material, then obtain through granulation, injection molding, the demoulding, skimming treatment, vacuum sintering, vacuum annealing process.
Wherein, polyvinyl alcohol accounts for 7%, sodium bicarbonate accounts for 20%, ta powder accounts for 73%, in volumn concentration;
Granulation: working temperature be 520 DEG C, described mixed powder to be a granulated into the circular granular of particle diameter 16 μm by operating pressure under being 14MPa;
Injection molding and the demoulding: the temperature described circular granular being injected into mould is 468 DEG C, pressure is 76MPa.Demould time: 8S;
Subsequently mixed powder is put into nonoxidizing atmosphere stove and be warming up to 800 DEG C with certain temperature rise rate, protective atmosphere is that 99.999% argon gas carries out skimming treatment, its intensification before first pass into pure argon gas at least 30min to get rid of furnace air, temperature control process: rise to 400 DEG C from room temperature with the speed of 1.5 DEG C/min, insulation 88min, argon gas intake 0.5L/min; 800 DEG C are risen to from 400 DEG C, insulation 195min, argon gas intake 1L/min with the speed of 2.0 DEG C/min; Powered-down again, the sample furnace cooling after degreasing, argon gas intake 1L/min, until close argon gas when being cooled to room temperature;
Being placed in vacuum tightness in high vacuum high temperature sintering furnace for the sample after skimming treatment with tungsten device is 10
-4pa ~ 10
-3pa, is warming up to 1680 DEG C with 13 DEG C/min, is incubated 190min, is chilled to 200 ~ 300 DEG C with stove, then is warming up to 1600 DEG C, insulation 230min with 17 DEG C/min, is warming up to 2000 ~ 2200 DEG C, insulation 270min with 8 DEG C/min; Sinter complete, vacuum tightness is 10
-3pa, is cooled to 1600 DEG C with the speed of 10 ~ 15 DEG C/min, insulation 30min; 1200 DEG C are cooled to, insulation 60min with the speed of 12 DEG C/min; 800 DEG C are cooled to, then furnace cooling with the speed of 10 DEG C/min;
Be placed in vacuum annealing furnace for the cooled sample of vacuum sintering with corundum container to be warming up to 1250 DEG C with certain temperature rise rate and to carry out stress relief annealing process, the vacuum tightness before heating up in annealing furnace at least will reach 10
-4pa, rises to 1250 DEG C with the speed of 15 DEG C/min from room temperature, and insulation 240min, vacuum tightness is 10
-4pa ~ 10
-3pa; Be cooled to 1000 DEG C with the speed of 5 DEG C/min again, insulation 180min, vacuum tightness is 10
-4pa ~ 10
-3pa; Be cooled to 800 DEG C with the speed of 10 DEG C/min, insulation 120min, vacuum tightness is 10
-4pa; Be cooled to room temperature with the speed of 20 DEG C/min, vacuum tightness is 10
-4pa.Finally carry out conventional aftertreatment and obtain porous tantalum.
Contriver detects the porous material density of above-mentioned porous tantalum finished product, porosity, aperture and various mechanical property by standards such as GB/T5163-2006, GB/T5249-1985, GB/T6886-2001: its foreign matter content is lower than 0.2%, its even pore distribution, density 12.87g/cm
3, porosity 23%, pore mean diameters 20 μm, Young's modulus 5.8GPa, flexural strength 167MPa, ultimate compression strength 123MPa.Through long-term test, this preparation technology's conforming product rate is up to 95.4%.This porous tantalum is suitable for the medical embedded material of alternative human dentale tissue very much.
In the method that above-described embodiment 4 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 |
5 |
6 |
7 |
8 |
Density (g/cm
3)
|
12.26 |
13.34 |
11.72 |
12.10 |
Porosity (%) |
24 |
20 |
29 |
26 |
Aperture (μm) |
20 |
14 |
24 |
18 |
Young's modulus (GPa) |
5.4 |
6.0 |
4.6 |
4.9 |
Flexural strength (MPa) |
173 |
176 |
162 |
168 |
Ultimate compression strength (MPa) |
122 |
127 |
116 |
120 |
More than obtained porous tantalum is highly suitable for the medical embedded material of human dentale tissue as an alternative.