Manufacturing method for a contact body of a vacuum interrupter, contact body for a vacuum interrupter and vacuum interrupter comprising such a contact body
The SPS process with placeholder elements addresses the inefficiencies of existing methods, enhancing mechanical and dielectric properties of contact bodies in vacuum switching tubes by ensuring precise shaping and high density without radial deformation.
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Patents
- Current Assignee / Owner
- SIEMENS AG
- Filing Date
- 2022-09-02
- Publication Date
- 2026-06-24
AI Technical Summary
Existing manufacturing processes for contact bodies in vacuum switching tubes are expensive, complex, and result in microstructural weaknesses leading to lower mechanical tensile strengths and dielectric failures, particularly in cracked contact welds.
A manufacturing process using a near-net-shape pre-processed contact body finalized through Spark Plasma Sintering (SPS) with post-densification under mechanical pressure, temperature, and electric current, utilizing a matrix to prevent radial deformation and incorporating placeholder elements to facilitate efficient compaction.
The process enhances mechanical stability, electrical conductivity, and thermal properties, reducing defects and improving dielectric performance by increasing density and tensile strength, while allowing for precise shaping and material composition.
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Abstract
Description
[0001] The present disclosure relates to a manufacturing process for a contact body for a vacuum switching tube, a contact body for a vacuum switching tube and a vacuum switching tube with such a contact body.
[0002] Various manufacturing processes for contact bodies are known in the prior art. In particular, machining from a solid material or assembling from cast or machined parts is expensive and complex.
[0003] It is also known to create contacts through costly arc remelting processes.
[0004] Furthermore, processes are known in which powders or powder mixtures are used as starting materials. For example, EP0731478A2 describes the possibility of sintering contact materials.
[0005] Contacts produced by pressureless sintering exhibit weaknesses in the microstructure of the CuCr composite material produced in this way, for example, which can lead to lower mechanical tensile strengths and dielectric failures, especially in the case of cracked contact welds.
[0006] Document DE 196 12 143 A1 discloses a manufacturing process for a contact body, according to the preamble of claim 1.
[0007] The purpose of the invention is to eliminate the existing disadvantages in the prior art.
[0008] This problem is solved by independent claims 1, 13 and 14, as well as the dependent claims.
[0009] A first embodiment relates to a manufacturing process for a contact body of a vacuum switching tube, wherein the contact body is configured to perform switching operations in the vacuum switching tube for low, medium and / or high voltage applications, and the contact body is formed from a near-net-shape pre-processed contact body, wherein the contact body and the near-net-shape pre-processed contact body have a radial extension and an axial extension, wherein the near-net-shape pre-processed contact body is finalized by means of a PLC process - Spark Plasma Sintering process - wherein, during finalization by means of PLC, a post-densification of the pre-processed contact body in the axial direction takes place in a die made of one or more materials from the material classes of Graphite, TZM, or steel under the influence of mechanical pressure, increased temperature and electric current flow, whereby a radial deformation of the near-net-shape pre-processed contact body is prevented or largely prevented by a matrix adapted to the outer contour of the near-net-shape pre-processed contact body.
[0010] In the SPS process, powders or sintered bodies are sintered and compacted by applying pressure to the object, introducing heat into the object, and flowing an electric current through it. The pressure is preferably applied uniaxially. The object in this case is a near-net-shape pre-processed contact body that is subsequently compacted.
[0011] For the purposes of this disclosure, "finalizing" means post-processing using a PLC method, in which, in particular, the near-net-shape pre-processed contact body is compacted in the axial direction. Thus, finalizing transforms the near-net-shape pre-processed contact body into the final contact body.
[0012] TZM is a solid-solution-hardened and particle-reinforced molybdenum-based alloy. TZM exhibits good strength properties even at temperatures above 1400°C, and especially above 2000°C, which is advantageous for the SPS process.
[0013] A near-net-shape pre-processed contact body is understood to be, in particular, a pre-fabricated blank of a contact body that already exhibits the contour of the finished contact body, i.e., the near-net-shape pre-processed contact body after post-processing using a PLC method. The inner contour of the die thus replicates at least the circumferential contour of the near-net-shape pre-processed contact body, so that no or only minimal deformation occurs in the radial direction of the near-net-shape pre-processed contact body—thus, deformation is largely prevented. Minimal deformation is understood to mean a change in length of less than 5%, preferably less than 2%, and particularly preferably less than 1%, in a radial direction.
[0014] The contact body can preferably be a contact disc, a contact carrier, or a complete contact. Axial densification refers to increasing the density of the contact body from, for example, 95% to 98% of the density of a solid body relative to the theoretical density of a solid body—that is, a body made of solid material, i.e., a non-porous body produced not by sintering but by, for example, casting or forming. Such densified, near-net-shape pre-processed contact bodies are particularly inexpensive to manufacture, require little or no rework, exhibit less wear, and are less prone to defects, while simultaneously offering a high degree of freedom in shaping and material composition, and the associated mechanical, electrical, and thermal properties.
[0015] The near-net-shape pre-processed contact body was produced by pressureless sintering. Pressureless sintering refers to sintering processes that do not require any additional pressure to be applied to the sintered body, in this case the contact body, or to processes where the pressure applied to the sintered body is less than 5 MPa, and in particular less than 2 MPa.
[0016] Furthermore, the near-net-shape pre-processed contact body is produced by pressureless sintering and has one or more recesses. The recesses are completely filled with one or more placeholder elements in the radial extent of the near-net-shape pre-processed contact body and are not completely filled with the one or more placeholder elements in the axial direction.
[0017] It is particularly preferred that the missing filling is located as far away as possible from the arc path, and in particular the arc path of the contact disc. In other words, the missing filling is located on the side opposite the arc path. Alternatively, the missing filling can also be located on the side of the arc path and on the side opposite the arc path. A further alternative is that the missing filling can be located on the side of the arc path.
[0018] In particular, it is preferred that one or more of the following be: Slots, recesses, and through-holes These are slots. Slots are, in particular, slots in the arc path, i.e., especially the contact disc, and / or slots in the outer surface of the contact body. for magnetic field generation. Recesses are preferably, for example, recesses in the center of the arc path, i.e., in particular the contact disc, and / or in other areas of the arc path, i.e., in particular the contact disc. One or more through-holes are particularly preferred for holding and mounting the contact body. Such a method and the use of placeholder elements enables a more efficient PLC process without negatively affecting the shape and dimensions relevant to the final properties of the contact body, while still defining a highly predictable end product.
[0019] It is also preferred that one or more placeholder elements are formed with metal or metal alloys.
[0020] It is further preferred that the metal or metal alloys of the placeholder elements are made of or comprise high-strength steels or refractory metals, in particular molybdenum, TZM, and / or tungsten, or the oxides, carbides, or nitrides of refractory metals. Refractory metals are understood to be, in particular, the high-melting-point, base metals of Group 4 (titanium, zirconium, and hafnium), Group 5 (vanadium, niobium, and tantalum), and Group 6 (chromium, molybdenum, and tungsten). The advantage of refractory metals lies particularly in their high melting point, high thermal and electrical conductivity, and low coefficients of thermal expansion. This significantly reduces or eliminates the risk of material bonding between the contact body and the die or contact element, thus achieving a high degree of reusability.Additionally, and optionally, the use of release agents made of graphite, boron nitride, and / or titanium diboride prevents the placeholder elements from sintering with the contact body and / or the die. A coating of the placeholder elements with graphite, boron nitride, and / or titanium diboride is particularly advantageous in preventing this sintering.
[0021] It is also preferred that one or more placeholder elements consist of pre-formed bodies that are inserted into one or more recesses before the PLC process. Such pre-formed bodies replicate the inner contour of a recess to be filled, either individually or in its majority, thus enabling a less labor-intensive and less error-prone process.
[0022] It is particularly preferred that the one or more placeholder elements consist of powder(s) that are introduced into the one or more recesses before the PLC process. This allows for the filling of a wide variety of geometries without the need to manufacture a separate form of placeholder element for each geometry. A coating of the powders forming the placeholder elements with graphite, boron nitride, and / or titanium diboride is particularly advantageous to prevent the placeholder elements from sintering with the contact body and / or the die.
[0023] It is particularly preferred that the powder(s) be post-compacted after being introduced and before the PLC process. Post-compaction achieves a high packing density and thus low compressibility of the placeholder element(s) formed from the powder.
[0024] It is particularly preferred that the introduction and subsequent compaction of the powder(s) is repeated several times. This further increases the packing density and achieves low compressibility of the placeholder element(s) formed from the powder.
[0025] It is also preferred that the maximum temperature of the near-net-shape pre-processed contact body during the SPS process does not exceed 99%, preferably 80%, particularly preferably 60%, of the melting temperature of the material of the near-net-shape pre-processed contact body. In the case of alloys or material mixtures, the melting temperature of the material is understood to be the melting temperature of the material with the lowest melting point.
[0026] It is also preferred that the maximum temperature of the near-net-shape pre-processed contact body is maintained for 30s to 15min, preferably for 1min to 5min, during the PLC process.
[0027] It is further preferred that the heating rate and / or the cooling rate to or from the maximum temperature of the near-net-shape pre-processed contact body during the PLC process is from 50K / min to 500K / min, preferably 150K / min ± 10K / min.
[0028] It is also preferred that, at least during the holding, or at least partially during the holding, of a maximum temperature of the near-net-shape pre-processed contact body during the PLC process, a uniaxial mechanical pressure of 5 MPa to 60 MPa, preferably 20 MPa ± 5 MPa, acts on the near-net-shape pre-processed contact body along the axial direction of the near-net-shape pre-processed contact body.
[0029] It is also preferred that, at least during the maintenance, or at least partially during the maintenance of a maximum temperature of the near-net-shape pre-processed contact body during the PLC process, a current density of 0.5 A / mm² to 5.0 A / mm², preferably 1.0 A / mm² to 3.0 A / mm², is effected in the near-net-shape pre-processed contact body.
[0030] The above parameters, process parameters, enable a particularly efficient PLC process, with simultaneously optimal process results.
[0031] A second embodiment relates to a contact body for a vacuum switching tube, wherein the contact body is manufactured according to one or more of the above embodiments.
[0032] Contact bodies manufactured in this way exhibit various advantageous properties. Among other things, the density increases from typically 95% TD (theoretical density) for pressureless sintered bodies to > 98% TD for PLC-finalized contact bodies, i.e., also to greater than 98% TD for post-compacted contact bodies, which leads to increased mechanical stability and improved electrical and thermal conductivity.
[0033] The flexural strength of test elements and contact bodies compacted using PLC also increases by at least 15% compared to pressureless sintered molded bodies.
[0034] Furthermore, an increased tensile strength of at least 15% is achieved in tensile tests for re-compacted test elements and contact bodies. Preferably, a change in the fracture pattern is simultaneously achieved, particularly with regard to CuCr (copper-chromium), where no or only a few chromium particles (less than 5%) are present that are torn out of or protrude from the copper matrix. Instead, it is further preferred that a high number of torn-out chromium particles are present.
[0035] It is preferred that, due to the generally higher mechanical strength compared to pressureless sintered molded bodies, a further reduced contact disc thickness can be achieved or is achieved.
[0036] Furthermore, it is preferred that the higher density and thus higher mechanical strength achieved compared to pressureless sintered molded bodies reduces arcing and increases the electrical lifetime of the contact body and especially the contact disc.
[0037] In contact bodies manufactured according to the above descriptions, there is a lower residual porosity compared to pressureless sintered bodies, recrystallization of a copper or silver material matrix, and an improvement in the bond between the embedded particles, for example, one or more made of chromium, carbon, tungsten, or other materials, and the material matrix. The matrix referred to in this paragraph as copper material matrix, silver material matrix, or material matrix refers to the material structure of the contact body and not to the die in which the contact body is sintered or finalized—in particular, densified—using PLC. The above changes compared to pressureless sintered bodies result in an improvement in the dielectric properties of the contact bodies, in particular a reduction in the probability of breakdown.A reduction in the reignition rate occurs because, after the switch has closed, leading to at least partial welding of the two contact surfaces of the contact elements (melted by arcing and / or fusion bridges), the subsequent opening of the switch and thus the separation of the two contact elements results in more brittle fracture behavior at the separation surfaces with inter-granular cracking (along the grain boundaries) and intra-granular cracking (within the grains themselves). There is less ductile deformation of the material matrix and less pull-out of the embedded particles. This results in a smoother surface that is also retained longer at the facing contact surfaces, with fewer protruding "peaks" or detached particles that could trigger reignitions and thus substantially impair the capacitive switching behavior.
[0038] It is also advantageous that, in the presence of non-circular morphologies of the embedded particles, especially hard particles, SPS finalization enables a reorientation of the textures of these particles, particularly hard particles, within the material matrix, e.g., by "rotating" plate-shaped particles, especially hard particles, more parallel to the contact surfaces. This also promotes the dielectric stability of the contact bodies during switching operations according to the mechanism described above.
[0039] In particular, it is advantageous that after SPS finalization, i.e., post-compaction, no or only minimal mechanical post-processing is necessary to achieve the desired target geometries of the contact bodies that were present before SPS finalization, i.e., before post-compaction.
[0040] The aforementioned methods are particularly suitable for joining several pre-processed sections of a contact body made of different or identical material compositions into a monolithic molded body, thus achieving a kind of gradation within the body. For example, combinations of areas with high mechanical strength, with specific thermo-mechanical properties, resistance to distortion due to temperature changes, good solderability, high electrical current-carrying capacity, or other properties are possible.
[0041] Contact bodies produced according to the above methods can be identified in particular in polished sections, by microstructure analyses and by chemical analyses - especially with regard to the presence of doping elements or auxiliary materials from the sintering processes.
[0042] A third embodiment relates to a vacuum switching tube, wherein the vacuum switching tube contains one, two, or more contact bodies manufactured according to one or more of the preceding embodiments. The contact bodies exhibit the advantages listed above. Figure 1: Schematic representation of a cross-section of a vacuum switching tube; Figure 2: Schematic representation of a contact body; Figure 3: Schematic representation of a contact body in a die for the PLC process; Figure 4: Schematic sectional view of a contact body in a device for a PLC process; Figure 5: Flowchart of a manufacturing process according to the invention.
[0043] The Figure 1Figure 1 shows a schematic representation of a cross-section of a vacuum switching tube 10. The vacuum switching tube 10 shown here has, by way of example, a first wall section made of an insulating material 12, a second wall section made of a metal 14 adjoining it, and a third wall section made of an insulating material 16 adjoining the latter. Alternatively, but not shown here, other wall constructions are also possible, for example, consisting only of an insulating material section to which flanges for fixed and / or moving contacts are attached.
[0044] The vacuum switching tube 10 further comprises a fixed contact flange 18 and a moving contact flange 20. The fixed contact rod 24 is arranged on the fixed contact flange 18. The moving contact rod 26 passes through the moving contact flange 20, and the moving contact rod 26 is gas-tightly connected to the moving contact flange 20 via a bellows 22, so that the moving contact rod 26 is movably arranged along the axial direction 202. A contact body 100 is arranged on both the fixed contact rod 24 and the moving contact rod 26 in the vacuum switching tube 10. The contact bodies 100 are designed as bodies of revolution and have a radial extension 201 and an axial extension in an axial direction 202. The contact bodies 100 are further designed here as fixed contact bodies on the fixed contact rod 24 and as moving contact bodies on the moving contact rod 26.
[0045] The Figure 2Figure 1 shows a schematic representation of a contact body 100, which is formed with a contact disc 110 and a contact carrier 120. The contact disc 110 has 201 radial recesses 210 and a central recess 210. The contact carrier 120 has spiral recesses 210. The recesses 210 in the contact carrier 120 serve to generate a magnetic field to support an arc quenching process. The radially oriented recesses 210 serve to influence the migration of the base points of an arc and / or to reduce eddy currents, and the centrally arranged recess 210 serves to prevent the formation of an arc in the center of the contact disc 110.
[0046] The Figure 3Figure 1 shows a schematic representation of a contact body 200 in a die 300 for the PLC process. The die 300 can project beyond the near-net-shape pre-processed contact body 200 in the axial direction 202 (not shown here) or be flush (shown here for simplicity). The die 300 limits the near-net-shape pre-processed contact body 200 in its radial extent 201 during a PLC process, so that a change in shape in the radial directions – the radial extent 201 – is prevented or largely prevented, meaning that there are no or only minimal changes in length in the radial extent 201. To prevent a change in the radial expansion of the near-net-shape pre-processed contact body 200 even with recesses 210, placeholder elements 400 are arranged in the recesses 210; two recesses 210 filled with placeholder elements 400 are shown here.To enable axial compaction of the near-net-shape pre-processed contact body 200, the placeholder elements 400 preferably do not extend over the entire axial extent 202 of the recesses 210. This allows for targeted post-compaction of the near-net-shape pre-processed contact body using the PLC process. Additionally, but not shown here, an optional central recess 210 in the contact disc 110 is also available (see figure). Figure 2 , with a placeholder element 400 completely filled in the radial extent 201, wherein the placeholder element 400 preferably does not extend over the entire axial extent 202 of the central recess 210.
[0047] The Figure 4Figure 1 shows a schematic sectional view of a near-net-shape pre-processed contact body 200 in a device for a PLC process. For the sake of simplicity, the near-net-shape pre-processed contact body 200 consists here only of the contact disc, see Figure 110. Figure 2 , obviously the process also works with a contact body 200, which is analogous to the Figure 2or is otherwise constructed. The device has a die 300 in which the near-net-shape pre-processed contact body 200 is inserted, wherein, according to the invention, a placeholder element 400 is inserted in the recess 210, the placeholder element 400 completely filling the recess 210 of the near-net-shape pre-processed contact body 200 in its radial extension 201, and leaving sufficient space in the axial direction 202 for subsequent compaction of the near-net-shape pre-processed contact body 200. During the PLC process, pressure, in particular uniaxial pressure in the axial direction 202, is exerted on the near-net-shape pre-processed contact body 200 by a first punch 350 and a second punch 360, and an electric current is also generated through the near-net-shape pre-processed contact body 200.The current flow also serves to generate Joule heating to achieve the desired process temperature for the PLC process. Additionally and optionally, other heating methods, not shown here, can support the process.
[0048] The Figure 5 Figure 1 shows a schematic flowchart of a manufacturing process according to the invention for a contact body 100. The process steps 1100, 1200, 1300, 1400, and 1500 listed below represent a sequence. Further subdivision of the process steps is possible, but is omitted here for the sake of clarity.
[0049] In a first process step 1100, a near-net-shape pre-processed contact body 200 is produced, preferably by pressureless sintering from one or more powder materials.
[0050] In a second process step 1200, the near-net-shape pre-processed contact body 200 produced in this way is inserted into a die 300 - which is particularly suitable to withstand the process parameters of the PLC process without bonding to the near-net-shape pre-processed contact body 200, in particular without a material bond - and according to the invention, recesses 210 are filled with placeholder elements 400, wherein the recesses 210 in the radial extent 201 of the near-net-shape pre-processed contact body 200 are completely filled with one or more placeholder elements 400 and in the axial direction 202 are not completely filled with the one or more placeholder elements 400.
[0051] The second process step 1200 can take place outside of a PLC system, within the PLC system, or outside the PLC system but in conjunction with other components of the PLC system. In particular, a first punch 350 and / or a second punch 360 and / or a support element (not shown) for the die 300 and / or the first punch 350 and / or the second punch 360 can already be positioned on the die 300. At the end of the second process step 1200, the die 300, together with the near-net-shape pre-processed contact body 200 and the placeholder elements 400, and optionally with the first punch 350 and / or the second punch 360 and / or the support element for the die 300, is inserted into the PLC system.
[0052] In a third process step 1300, the PLC process is carried out in the PLC system, preferably using one or more of the following parameters, process parameters: The maximum temperature of the near-net-shape pre-processed contact body 200 during the SPS process is no more than 99%, preferably 80%, and particularly preferably 60%, of the melting temperature of the material of the near-net-shape pre-processed contact body 200. The melting temperature refers, as explained above, optionally to the melting temperature of the material with the lowest melting point. The maximum temperature of the near-net-shape pre-processed contact body 200 is maintained during the SPS process for 30 s to 15 min, preferably for 1 min to 5 min. The heating rate and / or the cooling rate to or from the maximum temperature of the near-net-shape pre-processed contact body 200 during the SPS process is from 50 K / min to 500 K / min, preferably 150 K / min ± 10 K / min.At least during the holding, or at least partially during the holding, of a maximum temperature of the near-net-shape pre-processed contact body 200, a uniaxial mechanical pressure of 5 MPa to 60 MPa, preferably 20 MPa ± 5 MPa, is exerted on the near-net-shape pre-processed contact body 200 along the axial direction 202 during the PLC process; at least during the holding, or at least partially during the holding, of a maximum temperature of the near-net-shape pre-processed contact body 200, a current density of 0.5 A / mm² to 5.0 A / mm², preferably 1.0 A / mm² to 3.0 A / mm², is exerted in the near-net-shape pre-processed contact body 200 during the PLC process.
[0053] In a fourth process step 1400, the contact body 100, which was formed from the near-net-shape pre-processed contact body 200 in the third process step 1300, is removed from the PLC system and from the die.
[0054] In a fifth process step 1500, the placeholder elements 400 are removed from the contact body 100, the contact body 100 is optionally checked for errors, defects and other deficiencies and, if necessary, minor rework is carried out on the contact body 100, whereby the rework includes, for example, the removal of burrs and / or other traces on surfaces of the contact body 100 from the manufacturing process, in particular from the PLC process. Patent claims
[0055] 10 Vacuum switching tube; 12 First wall section made of an insulating material; 14 Second wall section made of a metal; 16 Third wall section made of an insulating material; 18 Fixed contact flange; 20 Moving contact flange; 22 Bellows, in particular corrugated bellows; 24 Fixed contact; 26 Moving contact; 100 Contact body; 110 Contact disc; 120 Contact carrier; 200 Near-net-shape pre-processed contact body; 201 Radial extension or radial direction; 202 Axial extension or axial direction; 210 Recesses in near-net-shape pre-processed contact body 200 or contact body 100; 300 Die; 350 First punch; 360 Second punch; 400 Placeholder element; 1100 First process section; 1200 Second process section; 1300 Third process section; 1400 fourth process section; 1500 fifth process section.
Claims
1. Method for producing a contact body (100) of a vacuum interrupter (10), wherein the contact body (100) is designed to perform, in the vacuum interrupter (10), switching operations for low-voltage, medium-voltage and / or high-voltage applications and the contact body (100) is formed from a near-net-shape preprocessed contact body (200), wherein the contact body (100) and the near-net-shape preprocessed contact body (200) have a radial extent (201) and an axial extent (202), wherein the near-net-shape preprocessed contact body (200) is finalized by means of a spark plasma sintering (SPS) method, in which a redensification of the preprocessed contact body (200) is effected in an axial direction (202) in a die (300), which is formed from one or more materials from graphite, TZM or steel, under the action of mechanical pressure, elevated temperature and electrical current flow, wherein a radial change in shape of the near-net-shape preprocessed contact body (200) is prevented or largely prevented with a die (300) which is adapted to the outer contour of the near-net-shape preprocessed contact body (200), wherein the near-net-shape preprocessed contact body (200) has been generated by means of pressureless sintering and has one or more cutouts (210), characterized in that the cutouts (210) are filled completely with in each case one or more placeholder elements (400) in the radial extent (201) of the near-net-shape preprocessed contact body (200) and are not filled completely with the one or more placeholder elements (400) in the axial direction (202).
2. Method for producing a contact body (100) according to Claim 1, characterized in that the one or the multiple placeholder elements (400) are formed with metal or with metal alloys.
3. Method for producing a contact body (100) according to Claim 2, characterized in that the metal or the metal alloys of the placeholder elements (400) are formed from or with high-strength steels or refractory metals or the oxides, carbides or nitrides of the refractory metals.
4. Method for producing a contact body (100) according to one or more of Claims 1 to 3, characterized in that the one or the multiple placeholder elements (400) consist of preformed bodies, which are introduced into the one or more cutouts (210) prior to the SPS process.
5. Method for producing a contact body (100) according to one or more of Claims 1 to 3, characterized in that the one or the multiple placeholder elements (400) consist of powder or powders, which are introduced into the one or more cutouts (210) prior to the SPS process.
6. Method for producing a contact body (100) according to Claim 5, characterized in that the powder or the powders are redensified after being introduced and prior to the SPS process.
7. Method for producing a contact body (100) according to Claim 6, characterized in that the introduction of the powder or powders and the redensification of the introduced powder or powders is repeated multiple times.
8. Method for producing a contact body (100) according to one or more of the preceding claims, characterized in that the maximum temperature of the near-net-shape preprocessed contact body (200) does not exceed 99%, preferably 80%, particularly preferably 60%, of the melting temperature of the material of the near-net-shape preprocessed contact body (200) during the SPS process.
9. Method for producing a contact body (100) according to one or more of the preceding claims, characterized in that the maximum temperature of the near-net-shape preprocessed contact body (200) is held for 30 s to 15 min, preferably for 1 min to 5 min, during the SPS process.
10. Method for producing a contact body (100) according to one or more of the preceding claims, characterized in that the heating rate and / or the cooling rate to or from the maximum temperature of the near-net-shape preprocessed contact body (200) is from 50 K / min to 500 K / min, preferably 150 K / min ± 10 K / min, during the SPS process.
11. Method for producing a contact body (100) according to one or more of the preceding claims, characterized in that at least during the holding, or at least partially during the holding, of a maximum temperature of the near-net-shape preprocessed contact body (200), a uniaxial mechanical pressure of 5 MPa to 60 MPa, preferably 20 MPa ± 5 MPa, acts on the near-net-shape preprocessed contact body (200) along the axial direction (202) of the near-net-shape preprocessed contact body (200) during the SPS process.
12. Method for producing a contact body (100) according to one or more of the preceding claims, characterized in that at least during the holding, or at least partially during the holding, of a maximum temperature of the near-net-shape preprocessed contact body (200), a current density of 0.5 A / mm2 to 5.0 A / mm2, preferably 1.0 A / mm2 to 3.0 A / mm2, is brought about in the near-net-shape preprocessed contact body (200) during the SPS process.
13. Contact body (100) for a vacuum interrupter (10), characterized in that the contact body (100) is produced according to one or more of the preceding claims.
14. Vacuum interrupter (10), characterized in that the vacuum interrupter (10) contains one, two or more of the contact bodies (100) produced according to one or more of the preceding Claims 1 to 12.