Sodium-resistant joining glass and the use thereof

Abstract

The sodium-resistant joining glass (1) is substantially free of ZrO.sub.2 and is based on a SiO.sub.2B.sub.2O.sub.3Na.sub.2OAl.sub.2O.sub.3 glass system. It is suitable for producing a joint of a metal and/or ceramic component with a further joining component (2, 3, 4) using the joining glass (1). Feedthrough-devices (20) using the joining glass (1) as fixing material are also disclosed.

Claims

1. A joining glass (1) that is free of ZrO.sub.2 except for at most impurities and that comprises, in % by weight based on oxide content: TABLE-US-00003 SiO.sub.2 40-44 B.sub.2O.sub.3 26-30 Na.sub.2O 5-15 Al.sub.2O.sub.3 17-25 MO .sup.0-<2, wherein MO represents, individually or in any combination, CaO and/or SrO and/or BaO.

2. The joining glass (1) according to claim 1, additionally comprising, individually or in any combination, in % by weight based on oxide content: TABLE-US-00004 ZnO 0-5 TiO.sub.2 0-5 SnO.sub.2 0-5 MgO .sup.0-15.

3. The joining glass (1) according to claim 1, which has a coefficient of linear thermal expansion .sub.20-300 C. in a temperature range of 20 to 300 C. of from 5.510.sup.6 K.sup.1 to 10.510.sup.6 K.sup.1.

4. The joining glass (1) according to claim 1, which has a coefficient of linear thermal expansion .sub.20-300 C. in a temperature range of 20 to 300 C. of from 5.510.sup.6 K.sup.1 to 8.510.sup.6 K.sup.1.

5. The joining glass (1) according to claim 1, which has a coefficient of linear thermal expansion .sub.20-300 C. in a temperature range of 20 to 300 C. of from 6.010.sup.6 K.sup.1 to 8.010.sup.6 K.sup.1.

6. The joining glass (1) according to claim 1, additionally comprising up to 30% by volume of an oxidic filler for setting or adjusting thermal expansion behaviour, corrosion resistance and/or flow behaviour.

7. The joining glass (1) according to claim 6, wherein the filler is in the form of particles and/or fibres.

8. A joint between a first joining component (2) and a second joining component (3, 4, 41), said joint comprising a joining glass (1), wherein the joining glass (1) bonds a joining area of the first joining component (2) to a joining area of the second joining component (3, 4, 41); wherein said joining glass (1) is free of ZrO.sub.2 except for at most impurities and comprises, in % by weight based on oxide content: TABLE-US-00005 SiO.sub.2 40-44 B.sub.2O.sub.3 26-30 Na.sub.2O 5-15 Al.sub.2O.sub.3 17-25 MO .sup.0-<2; and wherein MO represents, individually or in any combination, CaO and/or SrO and/or BaO.

9. The joint according to claim 8, wherein the first joining component (2) comprises a ceramic at least at the joining area thereof and the second joining component (3, 4, 41) comprises a metal and/or a ceramic at least at the joining area thereof.

10. The joint according to claim 9, wherein the ceramic at the joining area of the first joining component (2) and/or at the joining area of the second joining component (3, 4, 41) is selected from the group consisting of alumina, -alumina, -alumina, -alumina and sodium super ionic conductor (NASICON).

11. The joint according to claim 9, wherein the metal of the second joining component (41) has a coefficient of linear thermal expansion .sub.20-300 C. which in a temperature range is greater than or equal to a coefficient of linear thermal expansion .sub.20-300 C. of the ceramic in said temperature range.

12. A joint between a first joining component (2) and a second joining component (3, 4, 41), said joint comprising a joining glass (1), wherein the joining glass (1) bonds a joining area of the first joining component (2) to a joining area of the second joining component (3, 4, 41); wherein the first joining component (2) comprises a metal at least at the joining area thereof and the second joining component (3, 4, 41) comprises a metal at least at the joining area thereof; wherein said joining glass (1) is free of ZrO.sub.2 except for at most impurities and comprises, in % by weight based on oxide content: TABLE-US-00006 SiO.sub.2 40-50 B.sub.2O.sub.3 >25-30 Na.sub.2O 5-15 Al.sub.2O.sub.3 17-25 MO .sup.0-<2; and wherein MO represents, individually or in any combination, CaO and/or SrO and/or BaO.

13. The joint according to claim 12, wherein the metal (41) of the second joining component has a coefficient of linear thermal expansion .sub.20-300 C.>810.sup.6 K.sup.1.

14. An electrochemical energy storage and/or energy generation unit comprising at least one joint according to claim 8.

15. A sodium-sulphur battery or sodium-metal chloride battery comprising at least one joint according to claim 8.

16. An electrical feedthrough-device (20) comprising at least one joint that bonds a joining area of a first joining component (2) to a joining area of a second joining component (3, 4, 41), said joint comprising a joining glass; wherein said joining glass (1) is free of ZrO.sub.2 except for at most impurities and comprises, in % by weight based on oxide content: TABLE-US-00007 SiO.sub.2 40-44 B.sub.2O.sub.3 26-30 Na.sub.2O 5-15 Al.sub.2O.sub.3 17-25 MO .sup.0-<2; and wherein MO represents, individually or in any combination, CaO and/or SrO and/or BaO.

17. An electrical feedthrough-device (20) comprising a metal carrier element (30) with at least one feedthrough opening, and a metal functional component (31), wherein the metal functional component (31) is fixed within the feedthrough opening electrically insulated from the metal carrier element (30) by the joining glass (1) so that the feedthrough opening is sealed; wherein said joining glass (1) is free of ZrO.sub.2 except for at most impurities and comprises, in % by weight based on oxide content: TABLE-US-00008 SiO.sub.2 40-44 B.sub.2O.sub.3 26-30 Na.sub.2O 5-15 Al.sub.2O.sub.3 17-25 MO .sup.0-<2; and wherein MO represents, individually or in any combination, CaO and/or SrO and/or BaO.

18. An installation for disposal of waste, or a nuclear reactor, comprising an electrical feedthrough-device (20) according to claim 17.

19. A method of making a sodium-sulphur battery or a sodium-metal chloride battery comprising the step of hermetically sealing a housing (4) of the battery and/or closing off membrane components (2) of the battery with the joining glass (1) according to claim 1.

20. An electrochemical energy storage and/or energy generation unit comprising at least one joint according to claim 12.

21. A sodium-sulphur battery or sodium-metal chloride battery comprising at least one joint according to claim 12.

22. The installation or nuclear reactor according to claim 18, wherein the nuclear reactor is a breeder reactor.

23. A joint between a first joining component (2) and a second joining component (3, 4, 41), said joint comprising a joining glass (1), wherein the joining glass (1) bonds a joining area of the first joining component (2) to a joining area of the second joining component (3, 4, 41); wherein the first joining component (2) comprises a ceramic at least at the joining area thereof and the second joining component (3, 4, 41) comprises a metal at least at the joining area thereof; wherein said joining glass (1) is free of ZrO.sub.2 except for at most impurities and comprises, in % by weight based on oxide content: TABLE-US-00009 SiO.sub.2 40-44 B.sub.2O.sub.3 26-30 Na.sub.2O 5-15 Al.sub.2O.sub.3 17-25 MO .sup.0-<2; and wherein MO represents, individually or in any combination, CaO and/or SrO and/or BaO.

24. The joint according to claim 23, wherein the ceramic at the joining area of the first joining component (2) is selected from the group consisting of alumina, -alumina, -alumina, -alumina and sodium super ionic conductor (NASICON).

25. The joint according to claim 23, wherein the metal of the second joining component (41) has a coefficient of linear thermal expansion .sub.20-300 C. which in a temperature range is greater than or equal to a coefficient of linear thermal expansion .sub.20-300 C. of the ceramic in said temperature range.

26. An electrochemical energy storage and/or energy generation unit comprising at least one joint according to claim 23.

27. A sodium-sulphur battery or sodium-metal chloride battery comprising at least one joint according to claim 23.

28. An electrical feedthrough-device (20) comprising at least one joint according to claim 23.

Description

THE BRIEF DESCRIPTION OF THE DRAWING

(1) The invention will be explained in more detail using figures, which are briefly described here. All of the figures are purely schematic; the dimensions of the actual objects can deviate from the dimensions and/or the proportions in the figures, in which:

(2) FIG. 1 a is a cross-sectional view through a first joining component which is provided in certain regions with joining glass;

(3) FIG. 1b is a cross-sectional view through another first joining component which is provided in certain regions with joining glass;

(4) FIG. 2a is a cross-sectional view through a component assembly including a joint;

(5) FIG. 2b is a cross-sectional view through another component assembly including a joint;

(6) FIG. 3 is a cross-sectional view through a ZEBRA battery;

(7) FIG. 4 is a cross-sectional view through another ZEBRA battery;

(8) FIG. 5a is a cross-sectional view through a feedthrough-device;

(9) FIG. 5b is a top view of a feedthrough-device according to FIG. 5a;

(10) FIG. 6 is a cross-sectional view through an alternative feedthrough-device;

(11) FIG. 7 is a cross-sectional view through the containment of a reactor;

(12) FIG. 8 is a cross-sectional view through the containment of a reactor and the reactor itself.

THE DESCRIPTION OF THE PREFERRED EMBODIMENTS

(13) FIG. 1a schematically shows the section through a first joining component. The joining component (2) represents, so to speak, the substrate for the joining glass (1), which is located in certain regions on the surface of the joining component (2) and in these regions has entered into an integral bond with the joining component (2). The region at which the joining glass (1) is present can be the joining areas and are defined herein below as the joining areas at which joints with other joining components are produced. The joining component (2) shown with the joining glass (1) can produce joints with further joining components. In the present example, the joining component (2) consists of -alumina or -alumina or NASICON. As described, it is similarly possible for the alumina (2) of the joining component to be present only at those joining areas at which the bond is produced using the joining glass (1), and for the remaining regions of the joining component to consist of different materials.

(14) FIG. 1b shows substantially the same joining component with a joining glass as FIG. 1a, only that in this example the joining component (3) consists of -alumina or comprises the latter at least at those joining areas at which the joining glass (1) is present. All further statements made in relation to FIG. 1b are also applicable to FIG. 1b.

(15) FIG. 2a shows the section through a joint which is formed by a component assembly, bonded by the joining glass (1), consisting of the first joining component (2) and the second joining component (3). As can be seen with reference to FIG. 2a, the object shown is in principle a combination of FIGS. 1a and 1b. In this figure, the material of the first joining component (2) is again -alumina or -alumina and the material of the second joining component (3) is -alumina. The joining glass (1) bonds integrally to the surfaces of the joining components (2, 3) at the joining areas and can thereby produce a hermetic and durable bond between the joining components (2, 3).

(16) FIG. 2b shows the section through a similar embodiment to FIG. 2a, only that the first joining component is composed of -alumina or -alumina (2) and -alumina (3). In this exemplary embodiment, the second joining component (4) consists of a metal. It is clearly apparent to a person skilled in the art that a multiplicity of different overall components which can be adapted in accordance with the demands in relation to their use can be produced by appropriate combinations from the joints shown.

(17) FIG. 3 shows the section through a schematic ZEBRA battery. The battery is closed off by the jar-shaped housing (4) and the cover (3). The housing (4) and the cover (3) are bonded to one another by the joining glass (1). The cover (3) represents, so to speak, the first joining component and the housing (4) represents, so to speak, the second joining component of the joint described above. In a ZEBRA battery, the housing (4) usually consists of metal, e.g. of a high-grade steel, a nickel alloy or a low-carbon steel, and the cover (3) consists of alumina, in particular -alumina. The joining glass (1) according to the invention reliably and durably produces a tight bond between the two joining components, cover (3) and housing (4), and therefore the contents of the ZEBRA battery are closed off securely in the housing.

(18) The hollow-cylindrical semi-permeable membrane (2), which is usually produced from -alumina or -alumina, is located in the interior of the housing. The intermediate space between the inner wall of the housing (4) and the outer wall of the membrane (2) is filled by liquid sodium (11), which forms the anode. Through contact with the conductive housing (4), the latter similarly acts as the anode. The inner space of the hollow-cylindrical membrane (2) is filled, for example, with sodium tetrachloroaluminate as the electrolyte (10) and acts as the cathode. The semi-permeable membrane (2) consisting of -alumina or -alumina is permeable only to Na ions. It is bonded to the cover (3) by the joining glass (1). Here, the membrane (2) represents, so to speak, the first joining component and the cover (3) represents the second joining component in the general principle of the joint as described above. In this joint at this region of the ZEBRA battery, it is important that the joining glass (1) is impermeable to the electrolyte (10) and the liquid sodium (11), since otherwise electrolyte (10) and/or the liquid sodium (11) might be contaminated by the respective other substance, and accordingly the battery might be destroyed or at least the capacity thereof might be reduced.

(19) In this example, the cover (3) itself is an electrical insulator, and therefore an electrode (52) is required in order to make it possible to connect the battery with anode and cathode to an electric circuit. In the present example shown in FIG. 3, the metal rod (52) penetrates through the cover (3) through the sleeve (51). At this point, it is likewise conceivable to guide the metal rod (52), or in general terms the electrode, through the cover (2) in a glass-metal feedthrough comprising the joining glass according to the invention.

(20) FIG. 4 shows an alternative embodiment of the ZEBRA battery shown in FIG. 3. Since the joining glass (1) creates an electrically insulating joint between the two joining components at the bond between housing (4) and cover (41), it would also be possible to produce the cover (41) as shown in FIG. 4 from a metal or at least an electrically conductive material and to geometrically configure it in such a way that it does not come into contact with the electrolyte (10), such that it is possible to dispense with the led-through electrode (52) and the cover itself then acts as the cathode. The joining glass then bonds in particular the three joining components of housing (4), cover (3) and membrane (2) at one single region, here in the form of a ring.

(21) FIG. 5a schematically shows the section through a feedthrough-device (20). This feedthrough-device (20) comprises a carrier element (30), which in this example is represented by a metal cylinder. The carrier element (30) usually has the functionality of the outer conductor. In the described application areas, it usually is made of steel. Advantageous embodiments are made of carbon steel, austenitic steel and/or ferritic steel. For specific application areas, the carrier element (30) might be made of Kovar or a ceramic. The carrier element (30) also comprises a feedthrough opening which connects one side of the carrier element (30) with the other. The functional element (31) is arranged within the feedthrough opening. In this example the functional element (31) is represented by a rod which serves as electric conductor, also named inner conductor. The functional element (31) might be composed of different suitable materials such as Kovar and/or copper and/or alloys, for example NiFe alloys and/or CrNi alloys. The joining glass (1) fixes the functional element (31) within the feedthrough opening in an electrically insulating manner and seals the feedthrough opening at the same time. The joining glass (1) according to the invention provides the feedthrough-device (20) with the advantage that the feedthrough opening can be hermetically sealed. For the production of feedthrough-devices (20), the joining glass (1) is usually fused together with the carrier element (30) and functional element (31), thereby establishing a joint connection between the carrier element (30) and the joining glass (1) and the functional element (31).

(22) FIG. 5b shows the top view of the feedthrough-device (20) according to FIG. 5a. As can be seen the functional element (31) is arranged concentrically within the feedthrough opening. This geometry is usually applied in compression seals, in which the thermal expansion of the carrier element (30) is larger than the thermal expansion of the joining glass (1). As effect, during the fusion of the joining glass within the feedthrough opening and subsequent cooling the carrier element (30) so to say shrinks onto the joining glass and thereby generates a compressive stress towards the joining glass (1). This compressive stress enhances the mechanical force which is required to push the joining glass out of the feedthrough opening and thereby enhances the mechanical stability of the whole feedthrough-device (20).

(23) The feedthrough-device (20) as shown in FIGS. 5a and 5b represents a typical device of the class of the so called large feedthrough-devices.

(24) FIG. 6 shows the section through an alternative embodiment of a feedthrough-device (20) with a plurality of access opening within a carrier element (30). This so called planar element has dimensions which are wider than high. The feedthrough openings can be arranged in a matrix. The matrix itself is variable, which means that the location of the feedthrough openings can be chosen according to the desired application. This embodiment can e.g. be used to provide multiple electrical and/or electronic components with electric current, e.g. to power them and/or to lead signals generated by these components through the carrier element (30). The carrier element (30) might or might not seal the housing of a referring device. The carrier element (30) might be manufactured by a metal and/or alloy, or a ceramic, especially the materials described above.

(25) In FIG. 7, the containment (80) of an energy generation device is shown, for example a reactor, specifically a nuclear reactor or an installation for the disposal of toxic waste. Those have to be safely encapsulated within the containment (80), also in emergency and failure state situations. A feedthrough-device (20) according to the present disclosure is advantageously used in order to provide contact with the generator and/or devices within the containment. Such devices are e.g. devices to monitor the operation conditions of the generator and/or to steer the reactor or other devices.

(26) In FIG. 8, an energy generation device (81) such as a reactor is shown. This schematic illustration also comprises the cooling circuit of the reactor, in case of a fast breeding reactor especially its primary and/or secondary cooling circuit which is operated with liquid sodium as cooling medium. The feedthrough-device (20) can be used to supply steering and/or sensor and/or actuator devices and/or electric motors, especially within electric pumps, with electric current. Furthermore, the containment (80) can be supplied with the feedthrough-device (20) as described in the FIG. 7.

(27) Joining glasses (1) according to the invention were produced in conventional glass-melting processes. The details of glass melting are known to a person skilled in the art and are not repeated at this point.

(28) Table 1 below summarizes compositions and physical properties of four exemplary joining glasses (1) according to the invention, No. 1 to No. 4.

(29) TABLE-US-00001 TABLE 1 Examples of joining glasses according to the invention (compositions are in % by weight based on oxide content) No. 1 No. 2 No. 3 No. 4 Composition: SiO.sub.2 49 44 40 42 B.sub.2O.sub.3 26 26 30 26 Na.sub.2O 8 10 6 15 Al.sub.2O.sub.3 17 20 24 17 Properties: T.sub.g [ C.] 546 488 548 533 Density [g/cm.sup.3] 2.35 2.26 2.43 2.40 .sub.20-300 C. [10.sup.6 K.sup.1] 5.80* 6.61 5.62 8.34

(30) TABLE-US-00002 TABLE 2 Comparative examples of joining glasses (compositions in % by weight based on oxide content) CE 1 CE 2 Composition: SiO.sub.2 69.8 68.0 B.sub.2O.sub.3 15.6 13.0 Na.sub.2O 7.2 12.0 Al.sub.2O.sub.3 5.4 5.0 ZnO 2.0 1.0 BaO 1.0 Properties: T.sub.g [ C.] 505 565 Density [g/cm.sup.3] 2.31 2.44 .sub.20300 C.[10.sup.6 K.sup.1] 5.2 6.7

(31) Table 2 shows the composition and physical properties of joining glasses which lie outside the glass composition range according to the invention and as comparative examples are referred to herein below as CE 1 and CE 2.

(32) The glasses of the comparative examples have higher contents of SiO.sub.2 and lower contents of B.sub.2O.sub.3 and Al.sub.2O.sub.3 than the joining glasses according to the invention.

(33) The resistance of the joining glasses according to the invention as shown in Table 1 was determined compared to glasses CE 1 and CE 2 of the comparative examples shown in Table 2. For this purpose, a glass cube consisting of the glass in question is placed with the edge length in a bath of molten sodium at 300 C. for a defined period of time and the sample appearance, the structure of the sample surface and also the loss of mass are determined. All of the joining glasses according to the invention as shown in Table 1 prove to be more resistant than the comparative examples shown in Table 2 or show a higher coefficient of thermal expansion, which results in an improved ability to provide joining connections with metals as joining partner.

(34) The advantage of the joining glasses according to the invention over the prior art lies in the fact that they can be used for producing joints with ceramics and/or metal and also in the improved chemical resistance thereof.

(35) While the invention has been illustrated and described as embodied in a sodium-resistant joining glass and uses thereof, it is not intended to be limited to the details shown, since various modifications and changes may be made without departing in any way from the spirit of the present invention.

(36) Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

(37) What is claimed is new and is set forth in the following appended claims.