CA2034248A1 - Method for joining parts of ceramic high-temperature superconductor material - Google Patents
Method for joining parts of ceramic high-temperature superconductor materialInfo
- Publication number
- CA2034248A1 CA2034248A1 CA002034248A CA2034248A CA2034248A1 CA 2034248 A1 CA2034248 A1 CA 2034248A1 CA 002034248 A CA002034248 A CA 002034248A CA 2034248 A CA2034248 A CA 2034248A CA 2034248 A1 CA2034248 A1 CA 2034248A1
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- parts
- gap
- end faces
- temperatures
- heat treatment
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B37/00—Joining burned ceramic articles with other burned ceramic articles or other articles by heating
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B37/00—Joining burned ceramic articles with other burned ceramic articles or other articles by heating
- C04B37/003—Joining burned ceramic articles with other burned ceramic articles or other articles by heating by means of an interlayer consisting of a combination of materials selected from glass, or ceramic material with metals, metal oxides or metal salts
- C04B37/005—Joining burned ceramic articles with other burned ceramic articles or other articles by heating by means of an interlayer consisting of a combination of materials selected from glass, or ceramic material with metals, metal oxides or metal salts consisting of glass or ceramic material
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/45—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on copper oxide or solid solutions thereof with other oxides
- C04B35/4521—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on copper oxide or solid solutions thereof with other oxides containing bismuth oxide
- C04B35/4525—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on copper oxide or solid solutions thereof with other oxides containing bismuth oxide also containing lead oxide
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N60/00—Superconducting devices
- H10N60/01—Manufacture or treatment
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N60/00—Superconducting devices
- H10N60/80—Constructional details
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N60/00—Superconducting devices
- H10N60/80—Constructional details
- H10N60/85—Superconducting active materials
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
- C04B2237/02—Aspects relating to interlayers, e.g. used to join ceramic articles with other articles by heating
- C04B2237/04—Ceramic interlayers
- C04B2237/06—Oxidic interlayers
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
- C04B2237/30—Composition of layers of ceramic laminates or of ceramic or metallic articles to be joined by heating, e.g. Si substrates
- C04B2237/32—Ceramic
- C04B2237/34—Oxidic
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
- C04B2237/50—Processing aspects relating to ceramic laminates or to the joining of ceramic articles with other articles by heating
- C04B2237/78—Side-way connecting, e.g. connecting two plates through their sides
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2237/00—Aspects relating to ceramic laminates or to joining of ceramic articles with other articles by heating
- C04B2237/50—Processing aspects relating to ceramic laminates or to the joining of ceramic articles with other articles by heating
- C04B2237/80—Joining the largest surface of one substrate with a smaller surface of the other substrate, e.g. butt joining or forming a T-joint
Abstract
Method for joining parts of ceramic high-temperature superconductor material Abstract of the disclosure For joining parts of ceramic high-temperature supercon-ductor material of the composition Bi(2+a-b)(Sr(1-c)Cac)(3-a)PbbCu(2+d)Ox, where a is 0 to 0.3, b is 0 to 0.5, c is 0.1 to 0.9 and d is 0 to 2 and x has a value depending on the state of oxidation of the metals present, the end faces of the parts located at a gap spacing apart from one another are heated by means of a fuel gas/oxygen flame to temperatures from 750 to 875°C.
Simultaneously, a rod of the same material above the spacing gap is heated until the melt thereof drips off into the gap between the end faces of the two parts, completely filling the gap. At least the joint region between the two parts is then heat-treated for 7 to 100 hours at temperatures between 780 and 850°C.
Simultaneously, a rod of the same material above the spacing gap is heated until the melt thereof drips off into the gap between the end faces of the two parts, completely filling the gap. At least the joint region between the two parts is then heat-treated for 7 to 100 hours at temperatures between 780 and 850°C.
Description
x~
The present invention relates to a ~ethod for joining parts of ceramic high-temperature superconductor material of the composition Bi(z+ab~(Sr(lc~Cac)(3~Pk~Cu(2+d~C~/ where a is 0 to 0.3, b is 0 to 0.5, c is 0.1 to 0.9, d i~ 0 to 2 and x has a value depending on the state of oxidation of the metals present.
German Patent Application P 3,830,092.3, which is not a prior publication, has disclosed a process for preparing a high-temperature supexconductor of the compo~ition Bi2(Sr,Ca)3Cu20~ with x values fxom 8 to 10. In this case, stoichiometric mixtures of the oxides or carbonates of bismuthl strontium, calcium and copper are heated to temperatures fxom 870 to 1100C to form a homogeneous melt. The homogeneolls melt is cast in molds and solidifies therein. The castings taken from the molds are heat-treated fox 6 to 30 hours at 780 to 850C and then treated for at least 6 hours at 600 to 830C in an oxygen atmosphere. In this way, platelets of an edge length ox diameter of up to several cm and rods of up to 50 cm length and 10 mm diameter can be produced, each of which consist of a pure phase of the compound.
A di~advantage here is that the ceramic high~-temperature superconductor described above is so brittle that it cannot be rolled up for transport in the form of long current conductors onto a drum of large diame~er (for ~xample 2 m) without breaking or suffering crack~ r - 2 ~
particularly if the high-temperature superconduc~or i8 to be used for heavy current transmission.
Geramic high-temperature superconductors in powder form have also already been filled into silver tubes and the tubes have been elongated by swaging and deep-drawing until "wires" of the desired diameter were obtained, the high-temperatuxe superconductor powder present in the interior of the silver tubes being sinterable by heat treatment to give a coherent core. In this case, th~
oxygen required for forming the superconductor diffuses through the wall of the silver tubes.
The said "powder in tube" conductors withstand a certain degree of bending, so that in principle they can be used as current transmission conductors. A disadvantag thereof is, however, that they can be bent without destruction only at a small diameter~ and cannot be interconnected into complicated systems.
It is therefore the object of the present invention to indicate a method fo~ joining parts of ceramic high-temperature superconductor material to give complicated and e~tended structures, in which the junctions are also superconducting. This i5 achieved according tv the invention by heating the end faces of the parts located at a g~p spacing apart from one another by means of a fuel gas/oxygen -flame to temperatures fxom 750 to 875C
and simultaneously heating a rod of the same material above the spacing gap until the melt thereof drips off ~ 3 ~
into ~he gap between the end ~aces of the two parts, completely filling the gap, and then heat-trea~ing ak lea~t the ~oint region between the two parts for 7 to 100 hours at temperatures between 780 and 850C.
If desired, the process according to the invention can also be further developed by a~ heat-treating at temperatures from 815 to ~30C, b) the heat treatment time depending on the thickness of the ~unction, a thicker ~unction requiring a longer heat treatment time and vice versa, c) the end faces of the parts to be joined being in a : mutually parallei arrangement, d) the end faces of the parts to be joined being in a wedge shaped mutual arrangement, and e) the ceramic high-temperature conductor material parts to be join~d being each sheathed by a silver tube.
The co~pounds used according to the invention, for example Bi2(Sr,Ca)3Cu20~ (with x of about 8.~) melt incon-gruently, i~e. they do nat have a melting point, but amelting intervalO Moreover, th~ surface ~ension of this melt to~ards the solid phase in air is so high ~hat the melt does not Lmmediately run off from the solid phase.
The~e two properties are good prerequisites for a behavior which is similar to the joining of metals by autogenouæ welding.
~he melting of the compound Bi2~Sr,Ca)3Cu2O~ (with x of about 8.2~ takes placel for example, above 875C with loss of oxygen, the melting temperature dropping to abou~
780C at x of about 7.5. The solid present after the solidification of this melt is no longer superconducting, but it can be converted again into the superconducting state by heat treatment at about ~00C in a.ir.
In the method according to the invention, care must be taken to ensure that the end faces of the parts to be joined together are ~o hot that they can bond to the ~elt dripping off from the heated rod.
In the method according to the invention, a thin ~unction is heat-treated for 8 to 15 hours, whereas a thicker junction is heat-treated for up to 100 hours.
The heat treatment of the junction between the p~rts can be effected by subjecting the complete newly created shaped part to the heat treatment in an oven. However, _he h~at treatment can also be carried out locally by arranging an electric miniature oven with precise temperature measurement and control around the junction, or by local high-~requency induction heating or by direct he~ting using electrodes arranged transversely to the - 5 - ~33 junction, or by laser pulses.
In the welding according to the invention of shaped parts of high-temperature superconducting ceramic material, sheathed with a silver tube, par~icular care must bP
taken to ensure that the fuel gas/oxygen flame does not come into contact with the silver sheath and melts the latter, since ~he melting points of silver and of the high-temperature superconducting compound are not far apart. The silver-free joint region between the two parts joinad according to the invention can be, if desired, sheathed with silver afterwards.
Applications of the method according to the invention are illustrated diagrammaticall~ and in cross-section in the attachad drawing, in which:
Figure 1 shows the joining of two round rods with end faces arranged mutually parallel, Figure 2 shows the joining of two thic]cer round rods with the end faces in a ~edge~haped mutual arrangement, Figure 3 shows the joining of a thickex round rod and a thinner round rod, with the end faces in a mutually parallel arrangement, Figure 4 shows the joining of a thin disk to a round rod ..... .. .... .. .. . . . . . . . . . . . . . .
- 6 ~
with the end faces in a mu~ually parallel arrangement, Figure 5 shows a device for the local heat trea~ment of joints of round rods, and ~igure 6 shows temperature/resistance diagr~ms.
In Figure 1, the hatching A represen~s the solidified, non-superconducting melt, and the hatching B represents the superconducting compound after further heat treatment.
Illustration a shows the joint of the round rods Lmmediately after solidification of the melt which has dripped into the gap, while illustration b shows the junction after heat treatment for 24 hours at 815C.
In Figure 3, there are cavity regions in the longitudinal axis of ~he thicker and the thinner round rod.
In Figure 5, there is a ceramic heat carrier 1, which contains resistance-heating coils 2, is fi.xed via tube pas~ages 4 in holders 3. 5 represents the joint se~ of two round rods of ceramic high-tQmperature superconduc~or ~0 material. A thermocouple 6 is located closa to the ~oint seam 5.
In Figure 6, three measurements on the parts joinsd according to the invention by the procedure o~ E~ample 1 . . .. . . .. . .. ..
are represented; in detail, curves 1 and 2 show the measuxements on each of the joined parts and curve 3 shows the measurement in the joint region of the two parts beyond the weld.
Example l Two round rods of 5 mm diameter and 150 mm length, prepared by the process according to German Patent Application P 3,830l092.3, were pushed to~ether on a cer~mic substrate, leaving a gap, until their end faces were mutually parallel. The Pnd faces were heated to bright-red heat by means of a natural gas/oxygen flame.
SLmultaneously, a round rod o~ the same material above the gap was heated to such a degree that melt dripped off into the gap. The gap was uniformly ~illed with melt by slowly rotating the two round rods '(cf. Figure l, illustration a). After heat treatment of the joined round rods for 12 hours at 815C in an oven, the ~oint zone between the two ro~nd rods wa~ superconductiny (cf.
Figure 1, illu~tration b).
The transition temperature of the joint zone of the two round rods was 85.5 ~; to the right and lef~ thereof, ~ransi~ion ~emperatures of 86.0 and 85.5 ~ respectively w~re measured (cf. Figure 6).
Example 2 Two round rods of 12 mm diameter and 300 mm length, prepared by the process according to German Patent Application P 3,830,092.3, were placed with their end 5 faces in a wedge-shap~d mutual arrangement. By means of a propane gas/oxygen flame, the open wedge was heated and incipiently melted from the ba~e, before melt from a dripping round rod of the same material dripp~d from above into the wedge and filled it completely (cf. Figure 2). The joined round rods were then heat-treated in an oven for 24 hours at 800C.
In order to check whether the joint zone between the two round rods was now superconducting, -the specific resistance of the joined round rods was measured.
At 293 ~ before heat treatment: 1 n~x cm At 293 ~ after heat treatment . 0.001 ~ x cm At 77 R after heat treatment : 0 n x cm Example 3 Example 2 was repeated with the modi~ication that a round rod of 5 mm diameter and 120 mm length and a round rod of 16 m~ diameter and 40 mm length were clamped into a holding device in such a way that their axes were centered and theix end faces were arranged mutually parallel (cf. Figure 33.
- 9 ~
The measurement of the specific re~istance of tha joined round rods gave:
At 293 g kefore hea~ treatments 2~8 n x cm At ~93 K after heat treatment : 0.0015 n x cm At 77 R af~er heat ~reatmen~ : 0 n x cm E~amplQ 4 Example 2 was repeatPd with the modification that a round rod of 5 mm diameter and 80 mm length was joined perpen-dicularly to a circular plate (20 mm di~meter, 5 mm thicknes~) (cf. Figure 4). In this case, care was taken to ensure that the heating of the thin disk was less intensive than that of the round rod.
E~ample 5 Example 2 was repeated with the modifications that round rods of 8 mm diameter were joined to one another and the heat treatment was carried out by local heat trea~ment of the joint zone. For this purpose, an electric miniatuxe oven was used which wa~ placed around the round rod in the region of the ~aint zone and provided with a heat in~ulation of alumina wool. A laterally introduced thermocouple was used for temperature control tcf. Figure 5).
. . .. . . ..
The present invention relates to a ~ethod for joining parts of ceramic high-temperature superconductor material of the composition Bi(z+ab~(Sr(lc~Cac)(3~Pk~Cu(2+d~C~/ where a is 0 to 0.3, b is 0 to 0.5, c is 0.1 to 0.9, d i~ 0 to 2 and x has a value depending on the state of oxidation of the metals present.
German Patent Application P 3,830,092.3, which is not a prior publication, has disclosed a process for preparing a high-temperature supexconductor of the compo~ition Bi2(Sr,Ca)3Cu20~ with x values fxom 8 to 10. In this case, stoichiometric mixtures of the oxides or carbonates of bismuthl strontium, calcium and copper are heated to temperatures fxom 870 to 1100C to form a homogeneous melt. The homogeneolls melt is cast in molds and solidifies therein. The castings taken from the molds are heat-treated fox 6 to 30 hours at 780 to 850C and then treated for at least 6 hours at 600 to 830C in an oxygen atmosphere. In this way, platelets of an edge length ox diameter of up to several cm and rods of up to 50 cm length and 10 mm diameter can be produced, each of which consist of a pure phase of the compound.
A di~advantage here is that the ceramic high~-temperature superconductor described above is so brittle that it cannot be rolled up for transport in the form of long current conductors onto a drum of large diame~er (for ~xample 2 m) without breaking or suffering crack~ r - 2 ~
particularly if the high-temperature superconduc~or i8 to be used for heavy current transmission.
Geramic high-temperature superconductors in powder form have also already been filled into silver tubes and the tubes have been elongated by swaging and deep-drawing until "wires" of the desired diameter were obtained, the high-temperatuxe superconductor powder present in the interior of the silver tubes being sinterable by heat treatment to give a coherent core. In this case, th~
oxygen required for forming the superconductor diffuses through the wall of the silver tubes.
The said "powder in tube" conductors withstand a certain degree of bending, so that in principle they can be used as current transmission conductors. A disadvantag thereof is, however, that they can be bent without destruction only at a small diameter~ and cannot be interconnected into complicated systems.
It is therefore the object of the present invention to indicate a method fo~ joining parts of ceramic high-temperature superconductor material to give complicated and e~tended structures, in which the junctions are also superconducting. This i5 achieved according tv the invention by heating the end faces of the parts located at a g~p spacing apart from one another by means of a fuel gas/oxygen -flame to temperatures fxom 750 to 875C
and simultaneously heating a rod of the same material above the spacing gap until the melt thereof drips off ~ 3 ~
into ~he gap between the end ~aces of the two parts, completely filling the gap, and then heat-trea~ing ak lea~t the ~oint region between the two parts for 7 to 100 hours at temperatures between 780 and 850C.
If desired, the process according to the invention can also be further developed by a~ heat-treating at temperatures from 815 to ~30C, b) the heat treatment time depending on the thickness of the ~unction, a thicker ~unction requiring a longer heat treatment time and vice versa, c) the end faces of the parts to be joined being in a : mutually parallei arrangement, d) the end faces of the parts to be joined being in a wedge shaped mutual arrangement, and e) the ceramic high-temperature conductor material parts to be join~d being each sheathed by a silver tube.
The co~pounds used according to the invention, for example Bi2(Sr,Ca)3Cu20~ (with x of about 8.~) melt incon-gruently, i~e. they do nat have a melting point, but amelting intervalO Moreover, th~ surface ~ension of this melt to~ards the solid phase in air is so high ~hat the melt does not Lmmediately run off from the solid phase.
The~e two properties are good prerequisites for a behavior which is similar to the joining of metals by autogenouæ welding.
~he melting of the compound Bi2~Sr,Ca)3Cu2O~ (with x of about 8.2~ takes placel for example, above 875C with loss of oxygen, the melting temperature dropping to abou~
780C at x of about 7.5. The solid present after the solidification of this melt is no longer superconducting, but it can be converted again into the superconducting state by heat treatment at about ~00C in a.ir.
In the method according to the invention, care must be taken to ensure that the end faces of the parts to be joined together are ~o hot that they can bond to the ~elt dripping off from the heated rod.
In the method according to the invention, a thin ~unction is heat-treated for 8 to 15 hours, whereas a thicker junction is heat-treated for up to 100 hours.
The heat treatment of the junction between the p~rts can be effected by subjecting the complete newly created shaped part to the heat treatment in an oven. However, _he h~at treatment can also be carried out locally by arranging an electric miniature oven with precise temperature measurement and control around the junction, or by local high-~requency induction heating or by direct he~ting using electrodes arranged transversely to the - 5 - ~33 junction, or by laser pulses.
In the welding according to the invention of shaped parts of high-temperature superconducting ceramic material, sheathed with a silver tube, par~icular care must bP
taken to ensure that the fuel gas/oxygen flame does not come into contact with the silver sheath and melts the latter, since ~he melting points of silver and of the high-temperature superconducting compound are not far apart. The silver-free joint region between the two parts joinad according to the invention can be, if desired, sheathed with silver afterwards.
Applications of the method according to the invention are illustrated diagrammaticall~ and in cross-section in the attachad drawing, in which:
Figure 1 shows the joining of two round rods with end faces arranged mutually parallel, Figure 2 shows the joining of two thic]cer round rods with the end faces in a ~edge~haped mutual arrangement, Figure 3 shows the joining of a thickex round rod and a thinner round rod, with the end faces in a mutually parallel arrangement, Figure 4 shows the joining of a thin disk to a round rod ..... .. .... .. .. . . . . . . . . . . . . . .
- 6 ~
with the end faces in a mu~ually parallel arrangement, Figure 5 shows a device for the local heat trea~ment of joints of round rods, and ~igure 6 shows temperature/resistance diagr~ms.
In Figure 1, the hatching A represen~s the solidified, non-superconducting melt, and the hatching B represents the superconducting compound after further heat treatment.
Illustration a shows the joint of the round rods Lmmediately after solidification of the melt which has dripped into the gap, while illustration b shows the junction after heat treatment for 24 hours at 815C.
In Figure 3, there are cavity regions in the longitudinal axis of ~he thicker and the thinner round rod.
In Figure 5, there is a ceramic heat carrier 1, which contains resistance-heating coils 2, is fi.xed via tube pas~ages 4 in holders 3. 5 represents the joint se~ of two round rods of ceramic high-tQmperature superconduc~or ~0 material. A thermocouple 6 is located closa to the ~oint seam 5.
In Figure 6, three measurements on the parts joinsd according to the invention by the procedure o~ E~ample 1 . . .. . . .. . .. ..
are represented; in detail, curves 1 and 2 show the measuxements on each of the joined parts and curve 3 shows the measurement in the joint region of the two parts beyond the weld.
Example l Two round rods of 5 mm diameter and 150 mm length, prepared by the process according to German Patent Application P 3,830l092.3, were pushed to~ether on a cer~mic substrate, leaving a gap, until their end faces were mutually parallel. The Pnd faces were heated to bright-red heat by means of a natural gas/oxygen flame.
SLmultaneously, a round rod o~ the same material above the gap was heated to such a degree that melt dripped off into the gap. The gap was uniformly ~illed with melt by slowly rotating the two round rods '(cf. Figure l, illustration a). After heat treatment of the joined round rods for 12 hours at 815C in an oven, the ~oint zone between the two ro~nd rods wa~ superconductiny (cf.
Figure 1, illu~tration b).
The transition temperature of the joint zone of the two round rods was 85.5 ~; to the right and lef~ thereof, ~ransi~ion ~emperatures of 86.0 and 85.5 ~ respectively w~re measured (cf. Figure 6).
Example 2 Two round rods of 12 mm diameter and 300 mm length, prepared by the process according to German Patent Application P 3,830,092.3, were placed with their end 5 faces in a wedge-shap~d mutual arrangement. By means of a propane gas/oxygen flame, the open wedge was heated and incipiently melted from the ba~e, before melt from a dripping round rod of the same material dripp~d from above into the wedge and filled it completely (cf. Figure 2). The joined round rods were then heat-treated in an oven for 24 hours at 800C.
In order to check whether the joint zone between the two round rods was now superconducting, -the specific resistance of the joined round rods was measured.
At 293 ~ before heat treatment: 1 n~x cm At 293 ~ after heat treatment . 0.001 ~ x cm At 77 R after heat treatment : 0 n x cm Example 3 Example 2 was repeated with the modi~ication that a round rod of 5 mm diameter and 120 mm length and a round rod of 16 m~ diameter and 40 mm length were clamped into a holding device in such a way that their axes were centered and theix end faces were arranged mutually parallel (cf. Figure 33.
- 9 ~
The measurement of the specific re~istance of tha joined round rods gave:
At 293 g kefore hea~ treatments 2~8 n x cm At ~93 K after heat treatment : 0.0015 n x cm At 77 R af~er heat ~reatmen~ : 0 n x cm E~amplQ 4 Example 2 was repeatPd with the modification that a round rod of 5 mm diameter and 80 mm length was joined perpen-dicularly to a circular plate (20 mm di~meter, 5 mm thicknes~) (cf. Figure 4). In this case, care was taken to ensure that the heating of the thin disk was less intensive than that of the round rod.
E~ample 5 Example 2 was repeated with the modifications that round rods of 8 mm diameter were joined to one another and the heat treatment was carried out by local heat trea~ment of the joint zone. For this purpose, an electric miniatuxe oven was used which wa~ placed around the round rod in the region of the ~aint zone and provided with a heat in~ulation of alumina wool. A laterally introduced thermocouple was used for temperature control tcf. Figure 5).
. . .. . . ..
Claims (6)
1. A method for joining parts of ceramic high-temperature superconductor material of the composition Bi(2+a-b)(Sr(1-c)Cac)(3-a)PbbCu(2+d)Ox, where a is 0 to 0.3, b is 0 to 0.5, c is 0.1 to 0.9, d is 0 to 2 and x has a value depending on the state of oxidation of the metals present, which comprises heating the end faces of the parts located at a gap spacing apart from one another by means of a fuel gas/oxygen flame to temperatures from 750 to 875°C and simultaneously heating a rod of the same material above the spacing gap until the melt thereof drips off into the gap between the end faces of the two parts, completely filling the gap, and then heat-treating at least the joint region between the two parts for 7 to 100 hours at temperatures between 780 and 850°C.
2. The method as claimed in claim 1, wherein the heat treatment is carried out at temperatures from 815 to 830°C.
3. The method as claimed in claim 1, wherein the heat treatment time depends on the thickness of the junc-tion and wherein a thicker junction requires a longer heat treatment time and vice versa.
4. The method as claimed in claim 1, wherein the end faces of the parts to be joined are in a mutually parallel arrangement.
5. The method as claimed in claim 1, wherein the end faces of the parts to be joined are in a wedge-shaped mutual arrangement.
6. The method as claimed in claim 1, wherein the ceramic high-temperature conductor material parts to be joined are each sheathed by a silver tube.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4004363.0 | 1990-02-13 | ||
| DE4004363A DE4004363A1 (en) | 1990-02-13 | 1990-02-13 | METHOD FOR CONNECTING PARTS FROM CERAMIC HIGH TEMPERATURE SUPER-MATERIAL MATERIAL |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2034248A1 true CA2034248A1 (en) | 1991-08-14 |
Family
ID=6400029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002034248A Abandoned CA2034248A1 (en) | 1990-02-13 | 1991-01-16 | Method for joining parts of ceramic high-temperature superconductor material |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0442289B1 (en) |
| JP (1) | JPH04321569A (en) |
| KR (1) | KR0140380B1 (en) |
| CN (1) | CN1021176C (en) |
| AT (1) | ATE104654T1 (en) |
| CA (1) | CA2034248A1 (en) |
| DE (2) | DE4004363A1 (en) |
| NO (1) | NO179365C (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4208378A1 (en) * | 1992-03-16 | 1993-09-23 | Asea Brown Boveri | Current supply for superconducting appts. - comprises normal-conducting current supply for carrying current to high temp. superconductor |
| JP2907313B2 (en) * | 1993-12-02 | 1999-06-21 | 中部電力 株式会社 | Bismuth-based high-temperature superconductor joining method |
| CN100416714C (en) * | 2003-09-17 | 2008-09-03 | 住友电气工业株式会社 | Superconducting device and superconducting cable |
| JP2018127381A (en) * | 2017-02-08 | 2018-08-16 | 新日鐵住金株式会社 | Method for producing superconductive bulk conjugate |
| US10141493B2 (en) * | 2017-04-11 | 2018-11-27 | Microsoft Technology Licensing, Llc | Thermal management for superconducting interconnects |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0347770B1 (en) * | 1988-06-20 | 1996-03-27 | Daikin Industries, Limited | Process of producing a bismuth system oxide superconductor |
| DE3905424C2 (en) * | 1989-02-22 | 1994-02-17 | Vacuumschmelze Gmbh | Process for producing a superconducting connection between oxide superconductors |
-
1990
- 1990-02-13 DE DE4004363A patent/DE4004363A1/en not_active Withdrawn
-
1991
- 1991-01-16 CA CA002034248A patent/CA2034248A1/en not_active Abandoned
- 1991-01-22 AT AT9191100727T patent/ATE104654T1/en not_active IP Right Cessation
- 1991-01-22 EP EP91100727A patent/EP0442289B1/en not_active Expired - Lifetime
- 1991-01-22 DE DE59101410T patent/DE59101410D1/en not_active Expired - Fee Related
- 1991-02-09 CN CN91100970A patent/CN1021176C/en not_active Expired - Fee Related
- 1991-02-11 KR KR1019910002249A patent/KR0140380B1/en not_active IP Right Cessation
- 1991-02-12 NO NO910557A patent/NO179365C/en unknown
- 1991-02-12 JP JP3018893A patent/JPH04321569A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ATE104654T1 (en) | 1994-05-15 |
| DE4004363A1 (en) | 1991-08-14 |
| NO910557L (en) | 1991-08-14 |
| NO179365B (en) | 1996-06-17 |
| NO179365C (en) | 1996-09-25 |
| NO910557D0 (en) | 1991-02-12 |
| JPH04321569A (en) | 1992-11-11 |
| DE59101410D1 (en) | 1994-05-26 |
| EP0442289B1 (en) | 1994-04-20 |
| CN1054146A (en) | 1991-08-28 |
| CN1021176C (en) | 1993-06-09 |
| KR910015512A (en) | 1991-09-30 |
| EP0442289A1 (en) | 1991-08-21 |
| KR0140380B1 (en) | 1998-06-01 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| FZDE | Discontinued |