CN1036195A - Method of ceramic material that manufacturing superconductivity ceramics and other resistivity reduce and constituent and the conducting metal covering goods of making by these materials - Google Patents

Abstract

Pellet and the blend composition of polymkeric substance and softening agent and the method for ceramic material of some conducting metal pellet and polymkeric substance and softening agent blend composition manufacturing superconductivity ceramics and other metal clad resistivity reduction of a kind of some stupalith of employing (or their parent) are disclosed.According to the present invention, blend composition can be with common method moulding, and softening agent can be removed by means of extraction and/or volatilization method, and polymkeric substance can be volatilized, but and ceramic pellet sintering to generate desired ceramic product.

Description

Method of ceramic material that manufacturing superconductivity ceramics and other resistivity reduce and constituent and the conducting metal covering goods of making by these materials

The application is the part continuation application of 094, No. 179 U.S. Patent application of 1987.9.4 submission.

Just know that long ago some material is in low temperature condition following time, its effective resistivity descends, and equals zero in fact sometimes.Special ironically those at the metal and the metal oxide that substantially conduct electricity under the situation of non-resistance under some cold condition.For example, some metal will enter superconducting state as you know when being cooled to 4 degree Kelvin's thermodynamic scales when (hereinafter to be referred as a ° K), and some niobium alloy and niobium component are when about 15 ° of K, and some is then high to about 23 ° of K, just enters superconducting state.Recent findings, the oxide compound that contains lanthanum, barium and copper enters superconducting state when the temperature of about 30 ° of K, in some cases, enter superconducting state under the temperature that roughly is higher than 20 degree.Present progress has found to enter the material of superconducting state under the temperature near 100 ° of K, thereby can adopt liquid nitrogen to cool off.The performance that special ironically those its resistance reduce is to stable stupalith of time, thereby they might drop in the practical application.Although resistance is that reduce even phenomenon superconduction is observed so far under liquid nitrogen temperature or higher temperature, these performances still are considered to mainly can realize under subambient condition.Yet some sign shows, might be formed in by some prescription can show that resistance reduces under the general ambient conditions reliably even may be the stupalith of supraconductivity.

A kind of chemical formula near the unit structure cell is YBa ₂Cu ₃Oz(wherein Z generally is about 7) constituent and relevant various materials thereof are the stupalith combinations that are hopeful to can be used for superconducting applications especially.In a composition of these stupaliths, for example, the concrete practice is mixed the carbonate of solids component and/or oxide powder, is warmed up to about 1,000 ℃ temperature, removes the volatile materials of carbonic acid gas and so on.Compound is through milling and reheating (carrying out several times possibly to improve the mixing fully of compound) afterwards with its granulation, sintering then, last reach several hours or more than.Pellet behind the sintering can be annealed about 400 ℃, then progressively cooling.Another kind of chemical formula near the unit structure cell is Y _1.2Ba _0.8CuO ₄Constituent also be very significant.Even find that general expression formula is one group of compound of (LwMx) vAyDz, when particularly W equals 1-X, might reach superconducting state.Wherein L, M and A are the ceramic metal components, and D is the nonmetallic ingredient of oxygen and so on.Specific embodiment comprises that not only wherein L is yttrium (being Y), M is barium (being Ba), A is copper (being Cu), D is oxygen (being O), W is 0.6, x is 0.4, v is 2, y be 1 and z be 4 or less than 4 embodiment, but also comprise other embodiment, for example wherein L is the embodiment of lanthanum (being La), wherein L is the embodiment of neodymium (being Nd), wherein L is the embodiment of samarium (being Sm), wherein L is the embodiment of europium (being Eu), wherein L is the embodiment of gadolinium (being Gd), wherein L is the embodiment of dysprosium (being Dy), wherein L is the embodiment of holmium (being Ho), wherein L is the embodiment of ytterbium (being Yb), wherein L is the embodiment of lutetium (being Lu), wherein L contains the embodiment of scandium (being Sc), with some wherein L be the embodiment of the mixture of above-mentioned all metals, and wherein M contains the embodiment of strontium (being Sr), the wherein embodiment of M calcic (being Ca), with some wherein M for being selected from barium, the people such as the mixture of the metal of strontium and calcium.M.K.Wu are entitled as in the article of " in the novel mixing phase Y-Ba-Cu-O system of compounds under normal pressure 93K superconductivity " at " physical comment communication " (Physical Review Letters) of 1987 the 58th the 9th phases of volume and the people such as Engler has further discussed above-mentioned material in " U.S. chemical institute magazine " (Journal of the American Chemical Society) of 1987 the 109th volume 2848-2849 pages or leaves is entitled as the article of " superconductivity more than the liquid nitrogen temperature: preparation and the performance of the superconductor series take perovskite as primary raw material ".

Facts have proved that the pellet that suitably contains ceramic superconductive material is very suitable as research,,, get final product by firing to bond them together as long as powder is suppressed because their manufacture method are simple.This class stupalith generally is very crisp, so their easier forms with pellet are handled.When needing plain conductor, then can by the used similar fashion of original niobium alloy or compound superconductive with material adhesive to copper.But superconductor is likely and need makes the orthicon material with a large amount of these class materials in industrial purposes, bar, the practical shape of wire rod or sheet material and so on (is a size some shapes different with another size in its three-dimensional, for example, sheet material approaches with respect to its size in the plane, bar, wire rod and tubing are long with respect to their cross-sectional dimension) be processed into this class shape and have any problem by the compacting powder, therefore all seeking suitably and reliably these stupaliths be shaped still to keep other method of their low resistance conductive capabilities simultaneously at present.

According to reports, work out a kind of pipe that will fill material in the metal light wall pipe that resembles silver and so on then that ceramic powder is put at present and be drawn into method wiry.Method of evaporation is according to reports also in order to make superconductor material thin film from the heterogeneous material that contains yttrium, barium, copper and oxygen.Also have another method be with ceramic powder or even its composition be mixed in the organic fluid that resembles polyethylene glycol and so on so that it is squeezed into the form of wire rod.Wire rod after forming desired shape is burnt tackiness agent, again the powder sintering that left behind is become the filament goods.Band also creates by the method that ceramic pellet is embedded in the organic materials, and produced belt matter is gentle, can form sintering then.

These technology provide the research can be in order to the approach of the method for processing superconducting material, but still require other can be reliably and the method that easily the low resistance stupalith is formed at present.

Find that now some comprises polymkeric substance, softening agent and demonstrates the parent pellet of ceramic pellet that resistivity reduces, these stupaliths or the constituent of the pellet of pottery and parent thereof can suitably form to be fired into then and demonstrates the useful solid ceramic product that low-resistivity reduces.Polymkeric substance vapors away in sintering procedure, leaves over down to demonstrate the sintered ceramic solids that resistivity reduces.Softening agent was removed by extraction or volatilization before sintering.The non-ceramics component that occurs when firing is preferably unlikely during some volatilizations to be created in the material that ceramics component in the sintering process plays the byproduct of chemical reduction effect.The plasticity constituent practical shape of imaging bar, tubing and sheet material and so on that before firing, it can be shaped, thereby make the ceramic product that draws have desirable shape, and the plasticity constituent can bond with other plasticity constituent that contains insulating ceramic before firing, thereby its a part of resistivity of ceramic product that draws is reduced, another part and first part form an integral body, have insulating property.

Here among the embodiment of concrete narration, the plasticity constituent is bonding with a kind of blend composition of being made up of metal pellet, polymkeric substance and softening agent before firing, to produce a kind of metal clad solid ceramic that presents the resistivity reduction through agglomerating when firing.

An object of the present invention is to provide a kind of method of making the ceramic of resistivity reduction.

Another object of the present invention provides a kind of method that the stupalith of metalclad superconductivity ceramics and the reduction of other resistivity is formed.

Read following detailed description in conjunction with the accompanying drawings and can understand above and other objects of the present invention.

In the accompanying drawing, Fig. 1 is the skeleton view by the tubular products of the present invention's manufacturing; Fig. 2 is by the skeleton view of the composite club-shaped product of the present invention's manufacturing, for the purpose of explanation, can see the mandrel segment longitudinal extension from overcoat among the figure; Fig. 3 is the composite sheet product of making by the present invention, and for the purpose of explanation, each thin layer shows so that successive is stepped; Fig. 4 is that for the purpose of explanation, tubular core shows with the form of longitudinal extension from overcoat by the skeleton view of the composite tube product of the present invention's manufacturing.

Making the constituent that solids that resistivity reduces uses can make by prescription according to the present invention, and method is with polymkeric substance, softening agent and demonstrates ceramic pellet, the pellet of described stupalith parent or the pellet of described stupalith and described parent particle that resistivity reduces and mix.Parent comprises, for example, can be mixed the ceramic metal oxide or the carbonate that form desired pottery under heating condition.Here the resistivity of the reduction of being adopted typically refer at room temperature be 0.1 Europe-centimetre or littler resistivity, this is thundering low to stupalith usually.Preferably those have the stupalith of supraconductivity to recommendable stupalith.Supraconductivity may not be all to show under all temperature condition, and just shows in some temperature range.Optimal superconducting material is superconduct under liquid nitrogen temperature (approximately-196 ℃) or higher temperature, is put to practicality at this moment just easilier.

The method of testing that various definite supraconductivity can be arranged.In these methods of testing, there is a kind of method commonly used to relate to showy method.In this method, a tool magnet is placed on the ceramic disk.The material that will test is placed on the magnet of this disk, and makes the disk cooling with the liquid nitrogen that adds.If this block of material is floated, then this material is considered to superconductive material.

Should be noted that at present superconductor technology is developing rapidly, under room temperature or higher temperature, have reliable supraconductivity that what does not have is strange if therefore identify some stupalith.We think that the present invention is applicable to the solids of making the resistivity reduction from the pellet of this class material too.

The component of constituent can be mixed by the common mode of uniform mixing material that can form haply.For making constituent especially uniformly, can at room temperature each composition be carried out pre-mixing in the blending machine, again with blend composition fusion in common mixing machine (for example Banbury or Bradley Bender mixing roll) of doing, or in common edge-runner mill the fusion homogenizing.In the time of need carrying out continuous batch mixing, can adopt the meshed double screw mixer.The example of this mixer has Bei Ge. and MP mixer that Perkins company makes and Werner reach the not ZSK mixer of Chris Lederer company manufacturing.Preferably blend composition is pushed, is processed into fragment and extruding again, perhaps, for example, under heating state, carry out batch mixing, be mixed into even further to guarantee each the agent material in the constituent.

The ratio of each compound should be selected to such an extent that make the constituent that draws that plasticity be arranged in the constituent, and available common plastics technology extrusion molding is shaped.Usually, these compositions comprise the polymkeric substance of about 2 to 10 weight %, about 30 weight % or following softening agent, and the stupalith of about 60 weight %, its parent or both, as main component.Concerning most of blend compositions, softening agent accounts for about 2 weight % of constituent at least, and preferably at least about 5 weight %, ceramics component (being stupalith and/or its parent) accounts for about 90 weight % or following.

Be applicable to that polymkeric substance of the present invention comprises some materials like this, these materials at least can be under the situation that softening agent exists in its some process segment fluidization in addition, thereby make its under fluid state can with pottery and a plasticiser component blending, and after blending, be preferably under the room temperature (promptly about 20 ℃) curing.These polymkeric substance non-solvent normally concerning the granular ceramics component (being stupalith and/or its parent) of blend composition, perhaps if not nonreactive to granular ceramics component, make to remain unchanged haply in the blending process of each pellet.The molecular weight of polymkeric substance preferably is at least about 100,000, so that have excellent cohesive strength when mixing with ceramics component.Suitable enforcement thermoplastics of the present invention has: not plasticized polyvinyl chloride, polyvinyl chloride-propylene copolymer, polyvinyl chloride-ethylene copolymer, polyvinylidene dichloride and multipolymer thereof, polystyrene, impact resistance phenylethylene, the ABS(acrylonitrile-butadiene-styrene copolymer) resin, styrene butadiene block copolymer, low density (proportion 0.91) is to high-density (proportion 0.965) polyethylene, polyethylene and propylene, butylene, the 1-amylene, the 1-octane, hexene, the multipolymer of vinylbenzene etc., polyethylene and vinyl acetate, alkyl acrylate, sodium acrylate, the multipolymer of vinylformic acid etc., chlorinatedpolyethylene, chlorosulfonated polyethylene, polypropylene and propylene-olefin copolymer, polybutene and butylene-olefin copolymer, poly-4-methyl 1-amylene, thermoplastic polyurethane, polymeric amide, for example nylon 5, nylon 12, nylon 6/6, nylon 6/10, nylon 11, such as FEP(ethylene fluoride-propene polymer), poly(vinylidene fluoride), the fluorocarbon resin of polychlorotrifluoroethylene and so on; Vinyl cyanide-methyl acrylate copolymer, vinyl cyanide-vinyl chloride copolymer, methacrylonitrile-styrol copolymer, polymethylmethacrylate, cellulose acetate, cellulose acetate butyrate, polyoxymethylene, polycarbonate, polysulfones, polyphenylene oxide, polyethylene and butylene terephthalate polymer.

Although because thermoplastics is easier to fluidization so that carry out blending and curing by intensification and cooling respectively, and after mixing, be easier to push again or carry out aftershaping, thereby preferably adopt thermoplastics, but some thermosetting resins and crosslinkable resin also are applicable to purpose of the present invention, and this comprises: the polyethylene that the polyethylene that radiotreatment is crossed, peroxide treatment are crossed, crosslinked polypropylene, the Resins, epoxy of diazonium; Hydrocarbon, chlorine are in diene and paracril, furans, carbamide, melocol, phenolic aldehyde, Phthalic acid, diallyl ester, polyester and polysiloxane.

Consider from the angle of economy, generally all be ready to use and relatively say not too expensive binding agent polymkeric substance, because they can be burnt in finished product.Comparatively ideal polymkeric substance group is any mixture of polyolefine, Vinyl Acetate Copolymer, polystyrene and these polymkeric substance, wherein it would be desirable the polyolefine of polyethylene and so on.Really, molecular weight is about 100,000 and about 5,000, between 000 particularly about 250,000 and about 2,000, the polyethylene between 000, we think particularly suitable, because its is inexpensive, easily process with softening agent, and are the permissible products of metamorphic grade affected by environment.

Comparatively ideal polyolefine (can be mixture), its molecular weight height (be that molecular weight is at least 100,000, be preferably in 150,000 or more than, optimal situation 300,000 or more than).Polyolefinic scale load melt index preferably equals 0 haply, and the reduced viscosity of solution preferably be about 4.0 or more than.Polyolefine is at least 0.93 linear polyethylene to about 0.96 gram/cubic centimetre, high molecular weight polypropylene or the granular ethylene-butene copolymer of high molecular with density and is advisable.Other alkene has polybutene, ethylene-propylene copolymer, ethylene-butene copolymer, propene-1-butene copolymer and ethylene-propylene-butylene copolymer.Useful especially is the polyolefine that is selected from following polymkeric substance group: high molecular granular high density (0.93～0.96) polyethylene, high molecular new LDPE (film grade), high molecular weight polypropylene and the granular ethylene-butene copolymer of high molecular.The useful polyolefine of one of them this class is commercially available granular High molecular weight polyethylene, its standard load (2,160 grams) melt index is about 0.0, its high load (21,600 grams) melt index is about the 1.8(both under 190 ℃), density is 0.96, and the soltion viscosity of measuring when in 100 gram naphthalanes 0.02 gram polymkeric substance being arranged under 130 ℃ is 4.0.

Can adopt the blend composition of high molecular and low-molecular-weight polyolefin.What should keep firmly in mind is, along with the reduction of molecular-weight average, increases in the possibility of sintering procedure initial deformation (slump).

The polyolefine that is suitable for comprises the FD60-018 polyethylene, this can be buied by U.S. Unichem, also has extra high molecular amount linear polyethylene, this can be buied by U.S. Hirst company, and commercial disignation is " GUR-412 " (it is reported that the latter's molecular weight surpasses 1,000,000).

Constituent by blending of the present invention comprises the softening agent that component of polymer is used, this softening agent is following and interpolymer interaction at high temperature (generally between about 90 ℃ and about 200 ℃), form viscosity and be lower than the fluid composition of polymkeric substance itself, thereby make polymkeric substance be convenient to mix with solid particulate stupalith or its parent.In other words, thus the existence of softening agent has reduced and mixes and make the workability that the required power of constituent has improved blend composition.Usually, employed softening agent should be able to plastify under batch mixing, and its volatilization temperature is lower than the volatilization temperature of polymkeric substance, makes that the softening agent that is not extracted before firing can volatilization before the polymkeric substance volatilization.The others of invention described here often also should be owing to the use of a plasticiser component.For example, softening agent constituent that blending is come out be easier to be shaped and also impact resistance better.Such as being about to more detailed argumentation after a while, thus softening agent also is to be easy to from constituent extraction make constituent form more fixed shape and make constituent have a kind of material of the gas resultant effusion that is produced when porousness is convenient to polymkeric substance heating and volatilization.

By the low-resistivity ceramic product that the present invention makes, its final porousness at least a portion that obtains is also relevant with the constituent that blending is come out.

A plasticiser component can be water miscible or non-water-soluble, and can be almost any various softening agent commonly used, comprises their mixture.For example, the water-soluble plasticizer of Shi Yonging comprises glycol compound and the ethylene glycol itself that resembles glycol ether and glycol ester and so on; Resemble the glycerol compounds of glycerine itself and ethers thereof and ester class, comprise monoacetin; Resemble 1, (preferably those molecular weight are about 400 to about 20 for ammediol, tetramethylene ethylene glycol, ethylene glycol, glycol ether and their ethers and ester class, triglycol, polyoxyethylene glycol, in 000 the scope), propylene glycol, dipropylene glycol, polypropylene glycol (preferably molecular weight about 260 to about 1200 scope) and 2, the alkene glycol compound of 3-butyleneglycol and so on; Resemble the alkylphosphonic acid carboxylic acid ester cpds of triethyl phosphate and so on; With water-soluble poly mould assembly softening agent, for example polyvinyl alcohol, half hydrolyzed poly vinyl acetate, polyacrylic acid and polyvinylpyrrolidone etc.The softening agent that dissolves in organic solvent that is suitable for comprises, for example resembles the organosilane ester of sebacic acid class, phthalate, hard ester esters of gallic acid, adipic acid ester class and citric acid ester type and so on; Resemble the epoxy compounds of epoxidized vegetable oil and so on; Resemble the phosphoric acid ester of tritolyl phosphate and so on; The hydrocarbons of image-stone wax oil, mineral oil, oil and so on comprises lubricant, oils and oil fuel, hydrocarbon resin and resembles the pure compound of eicosane and so on; Resemble the low-molecular weight polymer of polyisobutene, polyhutadiene, polystyrene, Atactic Polypropelene, ethylene-propylene rubber(EPR), ethylene vinyl acetate oxidic polyethylene, coumarone resin and terpine resin and so on; Resemble the oils of Yatall MA and Toenol 1140 and so on; Chlorinated hydrocarbons; Sulphonamide; And pitch.The mixture that also can comprise water-soluble plasticizer and organic solvent softening agent.The same with polymkeric substance, a plasticiser component is normally nullvalent with the granular ceramics component of blend composition, thereby all pellets remain unchanged basically in the blending process.

Softening agent be the sort of can be by extraction or the softening agent from the compound of stupalith, polymkeric substance and softening agent, removed of volatilization, preferably be selected from the raw material group who forms by following: mineral oil, glycol ether, propylene glycol, dipropylene glycol, glycerine, single glyceride lactate, 1, ammediol, 2, ammediol, triethyl phosphate, polyvinyl alcohol and polyvinylpyrrolidone.Facts have proved, the mineral oil particularly suitable, particularly when the component of polymer employing resembles the polyolefin polymer of polyethylene and so on, all the more so.

Stupalith comprise those be selected from known under liquid nitrogen temperature or higher temperature the material group's of superconduct stupalith, for example those chemical formulas are YBa _1.67XCu _0.83yO _0.83zStupalith, wherein 1.67x, 0.83y and 0.83z are respectively in the material content with respect to barium, copper and the oxygen of wherein yttrium amount.In one embodiment, x is about 1.2, and y is about 3.6, and z is about 8.4; In another embodiment, x is about 0.4, and y is about 1, and z is about 4.But practical embodiment more of the present invention also can be prepared by the suitable parent of this class stupalith easily, for example pure metal itself and oxide compound thereof, carbonate and other compound, these materials can generate the metal oxide of used metal in the pottery when firing in oxygen containing atmosphere.In other words, the parent that is suitable for should be that those can lose their supplementary component by volatilization when heating, thereby makes remaining composition energy chemical combination form the parent of desired stupalith.For example, structure cell chemical formula in unit is YBa ₂Cu ₃O _ZCeramic composition can adopt YBa ₂Cu ₃The pellet of Oz adopts mole ratio to be about 1: 4: 6 Y ₂O ₃BaCO ₃With the parent pellet of CuO composition, or adopt YBa ₂Cu ₃O ₂The compound preparation that pellet and parent pellet are formed.

Stupalith and their parent that other ceramic metal oxide superconductor and resistivity reduce also are applicable to the present invention, for example, general expression is the stupalith that the resistivity of (LwMx) vAyDz reduces, wherein L, M and A are the metal ingredient of pottery, D is non-metal ingredient, oxygen for example, w, x, v, y and z have stipulated the relative proportion of each composition, the parent of this class pottery also is suitable for.

In one group of these material, w equals 1-x, and concrete system of compounds is through identifying, and wherein x is 0.4, and v is 2, and y is 1, and z is about 4 or less than 4.As top proposition was crossed, this system comprised such embodiment, and wherein L is a yttrium, and M is a barium, and A is a copper, and D is an oxygen.Other example also has, another kind of ceramic composition, and wherein L is selected from the metal group of being made up of La, Nd, Sm, Eu, Gd, Dy, HO, Yb, Lu, Sc and Y, and wherein M system is selected from the metal group of being formed and demonstrated the resistivity reduction by Sr, Ca and Ba.It is reported, be not only in above-mentioned Y-Ba-Cu-O pottery and in other pottery and also can observe supraconductivity, the following stupalith of chemical formula for example, NdBa ₂Cu ₃Oz, SmBa ₂Cu ₃Oz, EuBa ₂Cu ₃Oz, GdBa ₂Cu ₃Oz, DyBa ₂Cu ₃Oz, HoBa ₂Cu ₃Oz, YbBa ₂Cu ₃Oz, LuBa ₂Cu ₃Oz, Y _0.5Sc _0.5Ba ₂Cu ₃Oz, Y _0.5La _0.5Ba ₂Cu ₃Oz, Y _0.5Lu _0.5Ba ₂Cu ₃Oz, YSrCaCu ₃Oz, YBaSrCu ₃Oz, YBaCaCu ₃Oz, YbBaSrCu ₃Oz and YbBaCaCu ₃Oz wherein z is about 7.

Stupalith and/or their parent should be enough to be convenient to the blended pellet and provide with little.Stupalith or its granularity of their parent are preferably 100 orders or littler (size that is pellet should be enough to make pellet to pass through 149 microns sieve aperture).But when adopting parent, what also must consider is, pellet should be little be enough to make in the sintering process between the various parents interaction to form desirable ceramic product.So granularity 200 orders of parent or littler ideal (size that is pellet should make pellet can pass through 74 microns mesh).Certainly when stupalith system is used in the constituent, also can adopt these less granularities, do favourable like this.The personage who is familiar with sintering technology knows that the factor that affects sintered products character comprises granularity and sintering condition.But the pellet that can draw high every gram surface area values may need to use the usefulness of a large amount of non-ceramic materials for processing, thereby the product that draws has more porousness.Also can adopt the powder of tool bomodal size distribution, its benefit is to be convenient to processing and shaping.It is generally acknowledged that this is because pellet interactional cause in the process of liquid motion of different sizes.

When processing contains the material of polymkeric substance of polyolefine and so on traditionally is needs adding stablizer (oxidation inhibitor) and lubricant.This class additive, its consumption and use-pattern thereof are that the present technique field is known.Representative stablizer has 4,4 thiobiss (6 tertiary butyl m cresols) (" mountain is the nox all ") and 2,6-di-t-butyl 4 cresols (" her about Nore ").Selected stablizer and lubricant should be those materials that can burn in sintering procedure.Really, except that desired pottery and parent thereof, preferably avoid using those nonvolatile compositions before arriving sintering temperature.Here " volatilization " speech is meant the conversion that becomes gas or steam, is meant the high molecular or the gaseous substance that resemble polymkeric substance and so on especially, comprises resolving into the littler material of molecular weight.Therefore although Zinic stearas is a good lubricant under 0.5% concentration, other lubricant that resembles stearic acid and so on is then preventing that ceramic product from avoiding resembling aspect the pollution of material of zinc or zinc oxide and so on comparatively desirable.

Above-mentioned plasticity constituent can be in order to make the solids that resistivity reduces, method is that they are shaped as desired shape, use solvent extraction at least a portion softening agent in case of necessity, then constituent being heated to earlier is the volatilization temperature of softening agent at least, the general temperature between the boiling point of about 100 ℃ and softening agent, reheat is to the temperature of suitable volatilization polymkeric substance and any residual softening agent, generally between about 500 ℃ and about 700 ℃, then fire and do not cause their to volatilize under the higher temperature that is enough to the specific stupalith of sintering, this temperature generally is at least about 900 ℃.Although some pottery can carry out sintering under up to about 1600 ℃ temperature, the only sintering temperature of many ceramics components of the present invention is about 1100 ℃ or following, often greatly about 1000 ℃ or following.Sintering preferably continued about 1 to about 6 hours to demonstrate the hard bulk ceramics structure that desired resistivity reduces so that form.When adopting the parent pellet, method of the present invention is reacted to form the pottery that desired tool resistivity reduces them in sintering process.The personage who is familiar with sintering technology knows that the agglomerating temperature and time is all influential to the weave construction of ceramic product, and sintering condition should be controlled to such an extent that avoid producing decomposition, evaporation, fusion or undesirable grain growth.The bulk ceramics structure that is drawn is preferably slowly cooled off, lasted and reach 24 hours, it is annealed a little, specific annealing temperature can make its lasting some hrs.Since can consume a large amount of oxygen when polymkeric substance and/or softening agent burning, therefore in sintering procedure, must be ready to oxygen, in case anoxic in the finished product.Really, in sintering procedure, stupalith is carried out the development that significantly chemical reduction can prevent the electric property that requires.Therefore the non-ceramics component that during firing, exists preferably during some volatilizations a large amount of carbon residue of unlikely generation or other can generation in sintering procedure our undesirable material that ceramics component is played the byproduct of reductive action.For example, as you know, the polyolefine degraded time is can volatilization and may reduce the carbonaceous residue of ceramics component can not be created in sintering the time.On the other hand, can produce carbon fibre when some acrylic polymers is heated, thereby not too be applicable to the present invention.

Molding procedure can be carried out by means of the thermoplastic plastics shaping method of various standards.For example can carry out compression moulding, extrusion molding or injection moulding to the pellet of plasticity constituent.Also can adopt the combine forming method to process to material.For example can extruded sheet, carry out drawing, die-cut or be cut into desired shape then.Any waste material of these moulding processes normally can reuse.When adopting the continous way mixing equipment, can combine the mixed processes of continuously shaped operation and composition.

Firing of constituent can be carried out in general kiln.Heat-processed can be carried out in two steps, the softening agent evaporable temperature that earlier constituent is heated to the non-ceramics component of polymkeric substance and so on and does not remove, and then sintering is carried out in intensification.Not so sintering procedure also can be that constituent is brought up to the agglomerating temperature gradually, and volatilization can be carried out in heat-processed.Under any circumstance, the constituent that draws is porous a little, and some shrinks usually, and this is because the cause of having lost some materials and becoming closely knit in sintering process in volatilization process.The product, particularly sintering time that might make by the present invention in short-term, its porousness is undesirable to some purposes.On the other hand, when wishing that solid ceramic contacts with its fluid-tight on every side, then porousness is good.Under any circumstance, reduce porousness and can prolong sintering time, for example last 2 to 24 hours, along with porous minimizing, shrinkability increases.Reduce shrinkability also can adopt metal and do not adopt the oxide compound of metal or carbonate as parent, and in oxidizing atmosphere, carry out sintering, make in sintering process, oxygen to be absorbed.For example, can adopt metallic copper and not adopt the composition of cupric oxide as the constituent of institute of the present invention blending.Under any circumstance, when the product that contains the oxide containing ceramic material was produced in hope, sintering preferably was beneficial to the formation of those potteries in oxidizing atmosphere.Really, the oxygen level in the stupalith finished product depends on the environment at sintering place on some degree.

From the restrictive example of following not tool, can clearer understanding press the product that the present invention makes.

Example 1

36.3 gram Y ₂O ₃, 42.4 the gram BaCO ₃Mix with 5.0 gram polyethylene (particularly U.S.'s Hirst company molecular weight of producing believe be about 2,000,000 GUR412 polyethylene) and 20.0 mineral oil that restrain after 200 eye mesh screens screenings with 21.3 gram CuO.The constituent that draws under about 150 ℃, is adopted melt indexer, and extrusion moulding becomes roughly 2.5 millimeters long, 32 millimeters bar roughly of diameter.By in 1, flooding oil is extracted, and, progressively be heated to 1000 ℃ then, last 4 hours, make polymkeric substance and residual softening agent before reaching sintering temperature, vapor away at room temperature by the material that evaporation drying drew.Ceramic rod is sintered to about 1000 ℃ temperature, lasts 6 hours, then at 2 hours internal cooling to room temperature.The ceramic rod that draws demonstrates at room temperature the resistance in (under promptly about 22 ℃ temperature) about 2.2 Europe, and this is to calculate from the voltage and current that uses general instrument to measure.But when flooding in liquid nitrogen, the resistance of bar then is reduced to 0.23 Europe.

Example 2

With 46.2 gram Y ₂O ₃With 53.8 gram BaCO ₃Mix with 5.0 gram polyethylene and 20.0 gram oil.Getting 30 these constituents of gram then further mixes with the copper metal powder material of 8.5 grams.The constituent that draws is squeezed into clavate, extraction and sintering.The ceramic product that draws adopts the product of CuO preparation the same from color and example 1.

Example 3

Be squeezed into the rod of 30 cm long, 2.5 mm dias with the constituent of example 1, and make it form volution during extruding.After cooling, with oil extraction, then with coil as example 1 at 1000 ℃ of following sintering, to make the complete ceramic coil that must be able to handle completely.The same with most of potteries, the coil embrittlement.

Although plastics constituent of the present invention should be molded into the shape of finished product before firing, constituent not necessarily will moulding can not before being about to fire.The tool implementation-specific with the plastic composition of shape in addition can by present method preparation store with plastic form then and shipment when wanting to make the hard product till.For example, available strap material forming mould, length-to-diameter ratio are that 20: 1 and compression ratio are that the plastics constituent that 3: 1 screw-type extrusion machine extrusion molding is made up of polyethylene, mineral oil and pottery is made sheet material.Sheet material can one approximately from carrying out extrusion molding from about 10 to the thickness of about 75 Mills with from about 4 to about 40 inches width under 300 ℃ and about 500 °F.Then can be with through the form of cooled material with its plastics, with its extruded form or further after the moulding (for example cutting) store, when wanting to extract with sintering till.

Form after the net shape, may wish to reduce the plasticity of constituent in case further distortion between carrying and shelf lives.This can reach by extract at least a portion softening agent after moulding, but must carry out before storing and carrying, the volatile solvent that adopts softening agent to use, and this solvent is not effective solvent concerning stupalith or polymkeric substance.For example, when adopting mineral oil, can adopt hexane to extract as softening agent.Even do not consider deposit with handling process in produce undesirable distortion the time, also require at least a portion softening agent is extracted in some purposes, purpose is to prevent that formed material is in heating slump when burning polymkeric substance and residual softening agent.Under any circumstance, after the extraction softening agent, preferably formed material is carried out drying.As long as this at room temperature evaporates residual solvent usually, and can be by heating up and/or vacuumizing the acceleration drying process.

A problem should considering when making the product that shows the resistivity reduction is to provide electrical isolation for it.Everybody also knows, some stupalith has only and shows that at low temperatures resistivity reduces or supraconductivity." low temperature " speech here is meant below room temperature.Show at low temperatures that with preparation relevant two other problem that should consider of product that resistivity reduces is that electro-conductive material is cooled off and provides heat-insulating problem to product.The present invention can be in order to providing the product of above-mentioned one of them or an above problem of special consideration, and be specially adapted to be convenient to produce the constituent that this series products is used.

Wherein one group product comprises the product of the tape channel that resembles pipe that superconducting ceramics makes and so on, and shown in (10) among Fig. 1, passage wherein is for the usefulness of flow-through fluid cooling.Therefore have only when when keeping at low temperatures, just showing the desired resistance that has reduced when the solid part of the product of orthicon wall (12) and so on, just can make refrigerant in the passage of orthicon road (14) and so on, circulate.Certainly, as several applications and designing institute are allowed, also can make outside surface (18) circulation of refrigerant through pipe.Make the refrigerant can be by under the situation of tube wall in the porousness of stupalith, the flow that obvious desirable fluid flows through pipeline should be regulated to remedy refrigerant by increase or loss that tube wall was caused.The refrigerant that is produced (for example liquid nitrogen) helps to make this surface to keep low temperature from the evaporation of tube surface in addition.Not so also each hole can be sealed with suitable overlay.

Be noted that the present invention be not confined under the situation of certain particular job theory that some those skilled in the art that scholar proposes, the conduction of superconductor mainly betides surface of conductors, and conductor inside but is relatively to be in inert condition.Therefore except that cooling passage is provided, use superconductor to consume less material with tubular form, but unlikely minimizing surface-area.

The sort of pipe shown in Figure 1 can carry out extrusion molding with the common extruding machine that has pipe die again according to mixed polymer of the present invention, softening agent and stupalith and create extremely easily.The pipe that is extruded into is a constituent that is suitable shape, fires because it can or need not to extract in advance softening agent, sinters suitable direct refrigerative vitrified pipe again into.

From following limiting examples, can further understand this set product of making by the present invention.

Example 4

Melt index apparatus is equipped with the mould of using with extrusion molding 1/8 inch diameter tubing.The plasticity constituent that makes example 1 becomes coil by the pipe die extrusion molding with the tube forming that draws.Then with the oil extraction, again the solidified coil heats and at 1000 ℃ of following sintering.The product that draws is the individual tubing pottery coil that four diameters are 1 inch wire turn that has.

Another batch product comprises the insulating products of Fig. 2's the sort of superconducting material insulation rod shown in (20) and so on, and wherein ceramic insulating material (isolator) forms the insulation of electro-conductive material.There are many insulating ceramices also to can be used as heat insulator.Therefore when wanting the conducting element of product is insulated (for example resemble superconduction cylindrical core (22) if do not insulated just be vulnerable to electrical interference), then employing resembles that the sort of ceramics insulator of the annular insulating sleeve shown in (26) insulate beneficial to fuse (22) among Fig. 2.Obviously a plurality of fuses can be embedded in the same sleeve pipe and be insulated by this sleeve pipe.Obviously also available common method manufacturing contains two-layer above bar or the tubing of forming in addition.

Resembling the sort of combined type bar shown in Figure 2 can be easily mix polymkeric substance, softening agent and stupalith according to the present invention and carries out extrusion molding by the common extruding machine that suitable bar-shaped mould is housed then and made.Second kind of constituent comprises polymkeric substance, softening agent and the another kind of insulating ceramic that resembles aluminum oxide or trichroite and so on, can be similarly in addition blending carry out extrusion molding by pipe die then, make in the passage of the tubing that bar can be inserted the tape insulation pottery after the extrusion molding together with conductivity ceramics (or parent).This compound material can be sent in the material extrusion rod-type extruding machine and be extruded into the bar complex body again, two portions combine firmly.Not so pottery (or its parent) bar that also or one or more electric conductivity can be reduced carries out co-extrusion with common method under the situation of the feed existence that another kind is made up of second kind of tape insulation ceramic composition.Under any circumstance, this composite bar is the constituent of being convenient to make with moulding, carry out moulding and fire because it can or need not to extract in advance softening agent, sinter into then and have conductive core and the ceramic round bar that becomes the insulation thimble of an integral body with fuse.For example, one of them special purpose is that the composite bar that is in plastic state is made coil, make fire with sintering after the product (being the conductor of tape insulation) that draws be applicable to the purposes of electromagnetism aspect.

From following non-limiting instance, can further understand the product that this group is made by the present invention.

Example 5

Produce Y by example 1 ₂O ₃, BaCO ₃, the constituent formed of CuO, polyethylene and oil, be extruded into 2.5 millimeters bars of 5 cm long then.

Polyethylene, oil, aluminium, silicon-dioxide and magnesium oxide are mixed the known constituent of formation respectively, so that after sintering, draw ceramics insulator (being trichroite).This constituent (having insulativity) is molded into the sheet material of about 1 mm thick, and the sheet material looping that again this is contained the insulating ceramic parent is on the bar that contains the superconduction parent, to make the about 9 millimeters right cylinder charging of diameter.This charging is filled in the melt index apparatus, and heating is extruded into 2.5 millimeters new bars then.New bar center contains superconductor parent constituent, on every side around insulating ceramic matrix constituent is arranged.From the composite bar that this co-extrusion draws the extraction fuel-displaced after, bar is sintered to 1,200 ℃.The product that draws is to have fuse that the electro-conductive material mainly be made up of yttrium, barium, copper and oxygen makes and the telescopic ceramic composite of being made by insulating material round fuse.

Be noted that constituent of the present invention can be fired easily, because the volatilization of the extraction of softening agent and/or volatilization and polymkeric substance has produced the further hole of the gaseous state resultant that produced of the volatilization passage of overflowing of many formation.Resemble a specific embodiments of the composite prod of bar 20, the constituent of its outside (for example ring-shaped jacket (26)) comprises than evaporable polymkeric substance under the interior part temperature that for example polymkeric substance of fuse (22) is lower.Therefore when the polymkeric substance of interior part volatilizees, the prior volatilization of outside part polymkeric substance will be to have produced the usefulness of many holes confessions at the gas evolution that volatilization produced at fuse place.

Another embodies the example of the present invention aspect insulation shown in the composite sheet (30) of Fig. 3, and this sheet material has one deck conductivity ceramics (32) between two dielectric ceramic layers (36).Those skilled in the art that scholar knows, this composite sheet can be made easily like this: the sheet material that first extrusion molding is made by the constituent that draws by blending of the present invention makes the blend composition that wherein contains conductivity ceramics (or its parent) and polymkeric substance, softening agent and insulating ceramic, the sheet material of pad last layer band conductivity ceramics (or its parent) between two sheet materials that insulating ceramic arranged then is again with in the stratiform constituent feed-in laminating machine.Not so at this moment also available common co-extrusion manufactured composite sheet gives a co-extrusion mould by two extruding machine feed.Under any circumstance; this composite sheet also is that another kind can be made the constituent with moulding easily; fired because it can extract softening agent or need not extraction in advance in advance, sintering makes its formation have the ceramic sheet material of the conductive layer that is subjected to dielectric protection layer then.Before sintering, sheet material can strike out different shape in product processing.Obviously also available common co-extrusion method is set up inside and outside dielectric ceramic layer on the conductivity ceramics pipe.

From following non-limiting instance, can further understand this set product of making by the present invention.

Example 6

Two kinds of used in the example 5 constituents are pressed into the sheet material of about 1 mm thick respectively, again with the sheet material that contains the superconductor parent in the constituent in press with two constituents in contain the insulating ceramic parent sheet layer force together, the sheet material that contains the superconductor parent in the constituent is situated between in two constituents, contains between the sheet material of insulating ceramic parent.Oil is extracted from laminate, again laminate is carried out sintering like that by example 5 and have all ceramic products of the conductive sheet of tape insulation ceramic coating layer of two surfaces to produce.

Example 7

The constituent that example 5 is contained the insulating ceramic parent carries out extrusion molding to make the bar of 2.5 mm dias.Bar being wrapped with the sheet material of the superconduction parent that contains example 1 in the plasticity constituent, wrapped the sheet material that contains the insulating ceramic parent in its constituent again outside this sheet material, is 9 millimeters cylinder charging with the formation overall diameter.Then the pipe mold of this charging by example 4 itself is extruded into the about 3 millimeters tubing of diameter, observe the cross section of this tubing confirm at microscopically, the outside has successive insulating ceramic (trichroite parent) constituent in the tubing, is separated along the length of the tubing superconductor parent constituent layer by about 0.1 mm thick continuously.But because mould structure, the tubing that contains the superconductor parent in the constituent interrupts on periphery along the composite pipe length direction.Oil is extracted from composite pipe, and the pipe fitting heating and the sintering that will harden are the ceramic product that tubular conductor material is made haply to make again, and outside has the successive insulation layer in it.Those skilled in the art that scholar knows do not have the product of above-mentioned peripheral interruption situation to be not difficult with common co-extrusion device fabrication.

Be noted that the co-extrusion method is not to make can be processed into first part to demonstrate the resistivity, the second section that have reduced be the unique method of the matrix material of an isolator.For example, also can heat by the constituent of blending of the present invention or be bonded to the constituent that contains polymkeric substance, softening agent and ceramic insulating material.The bonding of two constituents can be easily by order treat the agglutinating surface in contact at foot in those surfaces remollescent temperature and time that is heated is effectively contacted with fluid-heating medium, will treat then to gather together in each surface of agglutinating to make each surface adhesion of adjoining or be melted in together.The temperature of heating medium is generally from about 180 ℃ to about 1200 ℃, when adopting polyolefine as the component of polymer of constituent preferably at least from about 500 ℃ to about 1000 ℃.Should be enough to surface adhesion is got up and the dimensional stability of unlikely destruction structure with the duration of contact of heating medium, and this when surpassing its fusing point, Heating temperature of each whole constituent is this situation to occur.In general, can be with the duration of contact of heating medium from about 0.05 to about 5 seconds.Heating medium can be that for example air or other resemble the gaseous medium of the gaseous state resultant etc. of combustion of natural gas.Make and adopt polyolefine to obtain gratifying bond effect, can for example adopt the gaseous state heating medium under about 1000 ℃, to bond duration of contact with about 0.2 to 2 second heating medium as the constituent of its component of polymer.In general, corresponding bonding surface temperature is roughly at 180 ℃ to 260 ℃, for example, and about 200 ℃.

Certainly in the process that manufactures a product by the present invention, can adopt co-extrusion and heat seal or agglutinating method simultaneously.For example, resembling the sort of composite bar shown in Figure 2 can carry out co-extrusion and make coil by above-mentioned.Then fire with sintering before the wire turn that adjoins of coil can be carried out heat seal, make that the product that draws behind the sintering is to have cohesive force thereby ceramic conductor tube quite blocky coiled type, its each wire turn is insulated from each other electric.

Obviously, containing product that multilayer conductive and dielectric ceramic layer replacing each other can be simply make by co-extrusion multilayer material or by the sealing constituent that heat seal or bonding have a less lamination.

Another set product comprises those products that resemble the insulated hollow pipe shown in (40) among Fig. 4, and this product not only insulate but also have for the general passage of stream of fluid coolant.The conducting element of therefore working as product, for example superconduction tubular core (42) has only and just shows the desirable resistance that has reduced but when needing to be insulated when remaining on low temperature, then should be equipped with heat insulation and the insulating ceramics insulator, the ring sleeve 46 that for example insulate, and resemble the passage that circulate among the passage (44) has refrigerant.

Resemble the sort of composite pipe blending easily shown in Figure 4 according to polymkeric substance of the present invention, softening agent and stupalith, carry out extrusion molding by the common extruding machine that suitable pipe mold is housed then.The compound material that another kind contains polymkeric substance, softening agent and other insulating ceramic can carry out blending similarly, and the extruding machine that can be contained in the pipe mold in its passage by the common tubing that its size feasible band conductivity ceramics (or parent) is housed carries out extrusion molding then.The tubing of band conductivity ceramics can be sent into compound material in the material extrusion rod-type extruding machine after packing in the tubing of tape insulation pottery, carries out extrusion molding again as the tubing complex body.Not so also can be with its constituent by the tubing (as for example shown in Figure 1) of blending of the present invention, heat seal or be bonded to and contain the outer of polymkeric substance, softening agent and ceramics insulator and put.Produce for carrying out routine, also can make can be by the inboard mould of being with the tubing of conductivity ceramics (or parent) of the overcoat of one or one above tape insulation pottery of common co-extrusion method co-extrusion.In any case, this composite pipe is the constituent of being convenient to make with moulding, fires because it can or need not in advance softening agent to be extracted, sinter into then have can be directly the ceramic tubing of refrigerative conductive layer and insulating coating in addition.

In some application of superconductor, more wish the contacted conducting metal of pottery, particularly superconductivity ceramics that can provide one deck and resistivity to reduce day.It is believed that, if ceramic conductor is temporarily not normal, the integrity that one deck conducting metal can holding circuit, and our invention is limited in the theoretical scope of special utilization.In general, clad can provide added strength to superconductivity ceramics, particularly toughness.

Have been found that having one deck at least as Fig. 2,3 and 4 illustrated those is the composite prod of conductive metal layer, can make by the present invention.For example, the silver-colored covering superconducting material web that can illustrate with (20) of Fig. 2, silver-colored covering (26) wherein surrounds conductivity ceramics (22).Obviously, can in identical silver-colored covering, embed many fuses; And contain bar or tubing more than two layers of constituent, also can adopt common process production.For example, the superconductivity ceramics of a silver-colored covering itself just can provide one to attack ceramic-insulated overcoat.

Though silver is a kind of preferred conducting metal, those can keep its electroconductibility and can other conducting metals of evaporable (for example gold) when burning altogether with ceramics component in oxygen-containing atmosphere, also think to be applicable to the present invention.

One as clad web illustrated in fig. 2, by blending one polymkeric substance, softening agent and stupalith of the present invention, and with its extrusion molding by an extruding machine commonly used that suitable clavate mould is housed, just can produce easily.A kind of second constituent includes a polymkeric substance, softening agent and for example pellet of the conducting metal of silver, can by similar methods in addition blending and extrusion molding cross a tubular die, the size of this mould will make the bar that has conductivity ceramics (or parent) can fill in the passage of the tubing that has conducting metal behind extrusion molding.Can be with this mixture feed-in one material extrusion rod-type extruding machine, and be extruded into one again and have the clavate mixture that two parts firmly bond together.Another kind of way is, under the additional feedback material of forming by the constituent that has conducting metal by second kind, and can one of co-extrusion or with ordinary method more than the bar of one the pottery (or its parent) that has the resistivity reduction.Under any situation, a kind of like this bar has been represented and a kind ofly has been convenient to produce and the constituent of product and moulding, because it can need to extract in advance compacted under in advance or not and fire, and sinter one into and have a conductive core and to become the ceramic round bar of the conducting metal covering of integral body with this fuse.For example, a kind of special application be with this mixture by the coiling of its plasticity form, make fire with sintering after this product (the ceramic conductor that covering is promptly arranged) of causing be an open stich that is suitable for electromagnetic application.Obviously, by co-extrusion-contain the extra play of above-mentioned insulating ceramic, can provide one deck additional ceramic insulating layer.

From following limiting examples, the product that this group makes by the present invention will be understood further.

Example 8

With a kind of atomic ratio that contains that can have been bought by W.R.Grace company on the market is that 1: 2: 3 the superconduction powder of yttrium, barium and copper and polyethylene (particularly can have a molecular weight of it is believed that about 2 by what American Hoechst company had bought, 000,000 GUR 412) and mineral oil (the particularly Sunthene 255 that can buy from Sun Chemical company) mix.Being adjusted at 150 ℃ of roller upsetting mixing machines (roller-head mixer) (Haake Rheocord) with 50rpm with one mixes this mixture twice.The constituent of gained is the oil of the powder that accounts for about 82.3 weight %, the polyethylene that accounts for about 2.9 weight % and about 14.8 weight %.At the about 150 ℃ bars that are the about ten sixth inches of diameter with this constituent extrusion moulding of a part down with a small-sized material extrusion rod-type extruding machine.Mix with silver granuel with GUR 412 and Sunthene 255 respectively, with second constituent of oil that a kind of polyethylene with the silver of about 82.3 weight %, about 2.9 weight % and about 14.8 weight % are provided.This argentiferous constituent is extruded into the tubing that external diameter is about 1/4th inches with a small-sized material extrusion rod-type extruding machine down at about 150 ℃.After this tubing cooling, four bar limits of containing the superconduction powder are filled in one section tubing with keeping to the side.With the filler tubing material extrusion rod-type extruding machine of packing into, reheat is to about 150 ℃, and is extruded into a bar that diameter is about 1/8th inches again.This bar has a fuse by the constituent that contains the superconduction powder, the superconduction powder with argentiferous around constituent in aggregates.The extraction of composite bar from immerse hexane is fuel-displaced then, and at room temperature makes the composite bar drying of gained with method of evaporation.Then with bar slowly two hours internal heating to 700 ℃ two hours, under 700 ℃, fired five hours, and at one hour internal heating to about 940 ℃ (promptly being lower than silver point), make polymkeric substance and remaining softening agent before the sintering temperature that arrives pottery, just vapor away, bar was fired under 940 ℃ ten hours respectively, at two hours internal cooling to 650 ℃, six hours internal cooling to 450 ℃ allow it be cooled to room temperature again.These heat, fire with the refrigerative operation all is to carry out in the atmosphere of oxygen.Float when cooling off in the liquid nitrogen of silver-colored covering ceramic round bar on permanent magnet that obtains like this.In addition, may be because the silver color layer be arranged, bar at room temperature also conducts electricity.

The manufacture method of superconductivity ceramics itself is not thought to depend in clad of the present invention aspect.The powder that uses in the example 8 has more fully in the U.S. Patent application of the unexamined of being submitted to simultaneously by people such as Lundsager and the application No. the (archives 01-7242) and narrates.

The example that another embodies clad of the present invention aspect can be illustrated by one deck conductivity ceramics (32) between two conductive metal (36) among Fig. 3.Obviously, for the personage who is familiar with this area, can produce this composite sheet with following step easily: at first extrusion molding is by the sheet material of the constituent that comprises a conductivity ceramics (or its parent) and a polymkeric substance, softening agent and conducting metal blend composition of blending of the present invention, make a sheet material stratification that has conductivity ceramics (or its parent) between two sheet materials that have a conducting metal then, and with in the constituent feed-in laminating machine after the stratification.Another kind of way is that giving altogether with two conventional extruding machine feedback material, the co-extrusion method of extruded mould also can form composite sheet.In either case; on behalf of another, a kind of like this composite sheet be convenient to produce constituent with moulding, because it can be in advance or need not extract softening agent in advance and fire and sinter into one have protected ceramic layer between conductive metal layer.Can punching press and/or formation sheet material during the product of the manufacturing different shape before sintering.Obviously, also can provide inside and outside two-layer metal clad for the tubing of conductivity ceramics with conventional co-extrusion technology.In addition, insulation layer and clad the two and ceramic layer can be combined as required, thereby increase the practicality of conductivity ceramics.

Be noted that co-extrusion and the nonproductive unique method that can be processed to form the matrix material of integral product, this integral product has one to present outside the first part of resistivity reduction, and also having an each several part both can be that isolator also can be the extention of conducting metal.For example, can use heat seal or the heat bonding of generally narrating in the above.Obviously, the product that contains the multi-turn layer can only be produced by the co-extrusion multilayer or with heat seal or the hot sticky constituent that is connected to less layer.

Another set product has comprised those insulation hollow tubular products that for example can be illustrated by (40) of Fig. 4.These tubing are metalclad each passage that promising round-robin fluid refrigerant provides electroconductibility that also contains.Therefore, conducting element at the product of for example superconduction tubular core (42), although require electroconductibility at room temperature, but also only keep just demonstrate required reduction at low temperatures resistance, at this moment the conducting metal of conduction usefulness both was provided, clad (46) for example for example also provides by it to allow each passage of passage (44) of refrigerant cycle be only favourable.Obviously, also can provide and attack the ceramics insulator overcoat with one.

These examples have been narrated each embodiment of the present invention.The personage who is familiar with this area also can recognize other embodiment from the research of specification sheets of the present invention disclosed herein or practice.Self-evident, under the spirit and scope of not leaving novel concept of the present invention, can carry out various improvement and variation.Certainly, the concrete prescription that the present invention is not subjected to exemplify here yet limits, but it comprises as from the improved form of the present invention in the following claims scope.

Above-mentioned case introduction each embodiment of the present invention.By studying relevant specification sheets of the present invention disclosed herein or practice explanation, those skilled in the art that scholar is understood that other embodiment.Self-evident, under the prerequisite of spirit that does not break away from new principle of the present invention and scope, can carry out various modifications and change to above-mentioned embodiment.It should be understood that in addition the present invention is not limited to cited and indivedual prescriptions and example in this specification sheets, but it comprises that these belong to the various modification that the present invention is carried out of following all claim scopes.

Claims (14)

1, a kind of integrated solid thing is characterized in that, this solids comprises the first part of low-resistivity reduction and the second section of conducting metal, and its manufacture method is as follows:

(first) firmly bonds together first constituent and second constituent, the roughly uniform blend composition that described first constituent is made up of following ingredients: demonstrate the stupalith that resistivity reduces at least about 60 weight %, the pellet of the parent of described stupalith, or both; Account for total blend composition about 2 at least a its molecular weight of about 10 weight % and be at least about 100,000 polymkeric substance; With softening agent from about 2 to about 30 weight % described polymkeric substance; Wherein component of polymer and a plasticiser component and ceramics component pellet Fails To Respond, thereby pellet remains unchanged in the blending process basically; And polymkeric substance wherein is to become fluid so that blending and can cured polymer after blending at least under the situation that softening agent exists; And described second constituent is the blend composition that contains the pellet of polymkeric substance, softening agent and conducting metal; With

(second) fires the good blend composition of bonding, makes temperature reach non-ceramics component evaporable temperature earlier, is warmed up to about at least 900 ℃ then, and described temperature is enough to sintered ceramic pellet or their parent and does not cause their volatilizations.

2, the integrated solid thing of claim 1 is characterized in that, in its forming process, blend composition system is bonded on second constituent by co-extrusion.

3, the integrated solid thing of claim 1 is characterized in that, in its forming process, blend composition system by heat seal bond to second constituent.

4, the integrated solid thing of claim 41 is characterized in that, this solids comprises composite bar, and this bar has the first part of the right cylinder fuse that series superconducting material makes and ties up to the metalclad second section that electroconductibility is provided under the room temperature.

5, the integrated solid thing of claim 1 is characterized in that, this solids comprises a slice ceramic sheet material of the resistivity reduction that is clipped between the two clad sheet materials.

6, the integrated solid thing of claim 1 is characterized in that, this solid also comprises the insulating ceramic of at least a portion.

7, the integrated solid thing of claim 1 is characterized in that, the conducting metal in the solids is a silver.

8, the integrated solid thing of claim 7 is characterized in that, this stupalith is 1: 2: 3 the superconducting metal oxide powder of forming by atomic ratio.

9, a kind of method of making the solid phase prod of moulding resistivity reduction is characterized in that this method comprises the following steps:

(first) produces roughly plasticity blend composition uniformly, and this blend composition comprises following composition: show the parent pellet of the stupalith pellet that resistivity reduces, described stupalith or both at least about 60 weight %; Account for the polymkeric substance of about 2 to about 10 weight % at least a molecular weight at least 100,000 of total blend composition; Softening agent with about 30 weight % or following described polymkeric substance; Wherein component of polymer and a plasticiser component and ceramics component pellet Fails To Respond, thereby pellet remains unchanged in the blending process haply; And polymkeric substance wherein, at least under the situation that softening agent exists, thereby be in the course of processing, can form fluid can with pottery and a plasticiser component blending and can cured polymer after blending:

(second) produces a kind of blend composition, and it comprises a kind of polymkeric substance, a kind of softening agent and a kind ofly can keep its electroconductibility and the material of nonvolatile conducting metal during firing.

(the third) firmly blend composition and make it to be molded into the constituent of the desirable shape of formation solid product bonds;

(fourth) removes softening agent with extraction process or volatilization method;

(penta) the heating blend composition makes the polymkeric substance volatilization; With

(own) fires at least about 900 ℃ constituent so that the sintered ceramic composition.

10, the method for claim 9 is characterized in that, extracts softening agent with a solvent to small part after moulding He before firing.

11, the method for claim 9 is characterized in that, polymkeric substance is a thermoplastic polymer, makes it can pass through to improve and reduce the temperature fluidify and the curing of polymkeric substance respectively.

12, the method for claim 9 is characterized in that, described polymkeric substance is a polyolefine.

13, the method for claim 9 is characterized in that, polymer system is selected from the polymkeric substance group who is made up of polyethylene, polypropylene and polystyrene; And softening agent system is selected from by mineral oil, glycol ether, propylene glycol, dipropylene glycol, glycerine, monoacetin, 1, ammediol, tetramethylene glycol, 2, the softening agent group that 3-butyleneglycol, triethyl phosphate, polyvinyl alcohol and polyvinylpyrrolidone are formed.

14, the method for claim 9 is characterized in that, stupalith wherein is a superconductor.

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